Plant Science 1

Jump to each topic by clicking on the relevant box below

Naming Plants:

What is meant by the term: binomial name?

Bi = two / nomial = name

Binomial names are the scientific names for a species.

It consists of genus (genera) and species names.

Each species has a unique binomial name. Closely related species will fall within the same genera and therefore share the genera name.

The species name often tells you something about the plant.

Binomial names are always Latin.

The genus is capitalised and species is lowercase.

Binomial names are italicised. When writing by hand they should be underlined (because handwriting can't be italicised clearly).

An example:

Galanthus nivalis (snowdrop); nivalis = of the snow

What is a cultivar?

Cultivar stands for 'cultivated variety'

A cultivar is a genetic individual that has been selected by people and is maintained in cultivation.

It is given a cultivar name. This is non-Latin and follows the species or hybrid name. It is not italicised, each word is capitalised and it is written within 'Inverted Commas'. If writing by hand, do not underline because it is not italicised unlike the genus and species name.

Cultivars are propagated via cuttings, grafting or tissue culture. This clones the cultivar, meaning genetically identical new plants are produced. These will all share the same cultivar name.

Cultivars are selected for specific qualities such as pathogen resistance, pest resistance, vigour, flower qualities, edible qualities, etc. This makes them very useful in gardens.

A couple of examples: Malus domestica 'Bramley's Seedling' or Salvia nemerosa 'Caradonna'

Why are scientific plant names in Latin?

What is a trade name?

Trade names are used as a marketing tool for plant cultivars.

All over the world plants are being bred and cultivars are selected. Cultivar names are usually given in the local language.

This can be a disadvantage when selling abroad where another language is spoken. For example, an English cultivar name may not capture much attention in France, Germany or Spain. If it were given a local language name in each country it could sell better.

Cultivars can be given a registered trademark name. These can be different in each country it is sold in.

Trade names are always CAPITALISED. They are never Latin words. The cultivar name should also be included as this is universal unlike trade names.

E.g.

Rosa CHANDOS BEAUTY 'Harmisty'

Define the term: propagation To make new individuals of a species or cultivar. This can be via seed or asexual/vegetative propagation.

Define the term: seed A propagule of a plant produced via sexual reproduction. Each seed is genetically different.

Define the term: variation Differences in a plant that's the result of genetic differences or environmental influences

Define the term: clone A genetically identical individual. In plants these can be produced via asexual reproduction

Define the term: asexual reproduction The cloning of a plant via cutting, grafting or tissue culture. This produces genetically identical new plant(s)

What denotes an interspecific hybrid? An x between the genera and hybrid name, e.g. Forsythia x intermedia A hybrid between F. suspensa and F. viridissima

What does PBR stand for? Plant Breeder's Rights

What denotes an intergeneric hybrid? An X before the binomial name, e.g. X Pyraria irregularis. This is a cross of Pyrus communis and Aria edulis. The intergeneric hybrid has a unique genus name that is used for all intergeneric hybrids made using the two genera

Who are PBR's registered with? The Animal and Plant Health Agency (APHA)

What is a subspecies? Differs in some characteristics from the species, usually due to geographical isolation, e.g. Euphorbia characias subsp. wulfenii

Why do people register a plant for PBR? To gain a portion of the sale as royalties. This is a source of income for plant breeders.

What is a botanical variety? A deviation from the type species that's less distinct than subspecies and more distinct than forma. E.g. Salix alba var. vitellina

How long do PBR's last? Potatoes, vines and trees: 30 years All other plants: 25 years

What is a botanical forma? A minor difference from the type species, below the differences seen in varieties and subspecies. E.g. Viburnum plicatum f. tormentosum

What is an F1 hybrid?

F1 hybrids are grown from seed. The F1 seeds are produced by cross pollinating two plants from different breeding lines. The breeding lines are inbred to select for particular traits.

This results in the F1 seeds being genetically quite similar, giving uniform traits.

These traits could be flower colour, pest or pathogen resistance, flavour qualities, etc.

F1 hybrids have hybrid vigour, making them vigorous and strong garden performers.

F1 hybrids are common in annuals and biennials as these can't be cloned and given cultivar names, unlike perennials.

F1 hybrids are given a name, e.g. Helianthus annuus 'Copper Queen' F1 (sunflower 'Copper Queen' F1)

Can a plant species be registered for PBR? No. Only cultivars.

What is an F2 hybrid?

Each number relates to a specific word, so if you think (1)________ is 'bananas' then if (1)________ appears later on in the passage, 'bananas' is the missing word.

All plants have a (1) b________ name. This is the (2)_________ name followed by the (3)_________ name. It's also called the plant's (4) s_________ name, and is in (5)_________ language. This is useful because it means (4)_________ plant names are (6)_________, meaning they are the same around the world. The (2)_________ is always (7)_________ whereas the (3)_________ is always (8)_________ . All (5)_________ plant names are typed in (9)_________. When writing by hand they should be (10)_________.

All plants have a (1) binomial name. This is the (2) genus name followed by the (3) species name. It's also called the plant's (4) scientific name, and is in (5) Latin language. This is useful because it means (4) scientific plant names are (6) universal, meaning they are the same around the world. The (2) genus is always (7) capitalised whereas the (3) species is always (8) lowercase. All (5) Latin plant names are typed in (9) italics. When writing by hand they should be (10) underlined.

Hint: the missing words in a random order species, italics, genus, underlined, scientific, lowercase, capitalised, Latin, binomial, universal

Extra Hint: (1) binomial

Extra Hint: (2) genus

Extra Hint: (3) species

Extra Hint: (4) scientific

Extra Hint: (5) Latin

Extra Hint: (6) universal

Extra Hint: (7) capitalised

Extra Hint: (8) lowercase

Extra Hint: (9) italics

Extra Hint: (10) underlined

Evolutionary Groups:

Name the scientific term for mosses Bryophytes

Name the scientific term for ferns Pteridophytes

Name the scientific term for conifers Gymnosperms

Name the scientific term for flowering plants Angiosperms

What are the two main groups of flowering plants? Monocotyledons and Eudicotyledons

State one similarity and one difference between mosses and ferns.

State one similarity and one difference between ferns and conifers

Similarities:

Both have vascular systems consisting of tracheids and phloem
Both have a perennial life cycle

Differences:

Ferns reproduce via spores where as conifers produce seeds (gymnosperm means 'naked seed', which is a seed that's not enclosed within an ovary)
Conifers produce cones whereas ferns produce sporangia (spore producing structures on the undersides of their fronds)
Conifers are woody whereas ferns are herbaceous

State the similarities and differences between conifers and flowering plants

Similarities:

Both contain phloem
All conifers become woody (lignify) and some angiosperms become woody
Both reproduce via seed
Both produce pollen

Differences:

Conifers have tracheids whereas angiosperms have xylem
All conifers are woody whereas not all angiosperms are woody - some are herbaceous
All conifers are perennial whereas angiosperms have a range of lifecycles (ephemerals, annuals, biennials and perennials)
Angiosperms are broadleaf plants whereas conifers produce needle or scale leaves
Conifers produce cones whereas angiosperms produce flowers
All conifers are wind pollinated whereas angiosperms are either wind or animal (insect) pollinated
Conifers have seeds that are not enclosed by an ovary ('naked seeds') whereas angiosperms have seeds enclosed within an ovary

Each number relates to a specific word, so if you think (1)________ is 'bananas' then if (1)________ appears later on in the passage, 'bananas' is the missing word.

(1)_________ have two seed leaves whereas (2)_________ have (3)_________. (1)_________ have (4)_________ leaf veins whereas (2)_________ have (5)_________ veins. (1)_________ can produce (6)_________, such as in trees and shrubs, whereas (2)_________ do not produce (6)_________. (1)_________ produce (7)_________ root systems whereas (2)_________ have (8)_________ roots. (1)_________ have flowers with (9)_________ and (10)_________ whereas (2)_________ have flowers with (11)_________. (1)_________ flower parts are in multiples of (12)_________ whereas (2)_________ have (11)_________ in multiples of (13)_________. (1)_________ have two germination strategies: (14)_________ where the seed leaves are above ground, or (15)_________ where the seed leaves remain below ground.

(1)Eudicotyledons have two seed leaves whereas (2)monocotyledons have (3)one. (1)Eudicotyledons have (4)reticulate leaf veins whereas (2)monocotyledons have (5)parallel veins. (1)Eudicotyledons can produce (6)wood/lignin, such as in trees and shrubs, whereas (2)monocotyledons do not produce (6)wood/lignin. (1)Eudicotyledons produce (7)tap root systems whereas (2)monocotyledons have (8)fibrous roots. (1)Eudicotyledons have flowers with (9)petals and (10)sepals whereas (2)monocotyledons have flowers with (11)tepals. (1)Eudicotyledon flower parts are in multiples of (12)four or five whereas (2)monocotyledons have (11)tepals in multiples of (13)three. (1)Eudicotyledons have two germination strategies: (14)epigeal where the seed leaves are above ground, or (15)hypogeal where the seed leaves remain below ground.

Hint: the missing words in a random order reticulate, three, eudicotyledons, wood/lignin, sepals, hypogeal, parallel, tap, monocotyledons, tepals, one, fibrous, epigeal, four or five

Extra Hint: (1) eudicotyledons

Extra Hint: (2) monocotyledons

Extra Hint: (3) one

Extra Hint: (4) reticulate

Extra Hint: (5) parallel

Extra Hint: (6) wood/lignin

Extra Hint: (7) tap

Extra Hint: (8) fibrous

Extra Hint: (9) petals

Extra Hint: (10) sepals

Extra Hint: (11) tepals

Extra Hint: (12) four or five

Extra Hint: (13) three

Extra Hint: (14) epigeal

Extra Hint: (15) hypogeal

Up

Define the term: ephemeral A plant that completes several lifecycles in one season

Define the term: annual A plant that completes its lifecycle within one year

Define the term: biennial A plant that completes its lifecycle in two years

Define the term: perennial A plant that lives more than two years

Name the two types of perennials Herbaceous perennials (non-woody) Woody perennials (lignify/produce wood)

Classify conifers and ferns by their lifecycles All conifers are woody perennials All ferns are herbaceous perennials

What is the difference between evergreen and deciduous? Evergreens retain their leaves throughout the year whereas deciduous plants lose their leaves when they are dormant

Where do herbaceous perennials store energy? Either in: rhizomes, bulbs, corms, root tubers, stem tubers or swollen tap roots

Where do woody plants store energy? In their woody stems and root systems

What's the difference between a tree and a shrub? A tree does not naturally produce branches near the base whereas shrubs are branched from near to ground level

Name the stages of a plant lifecycle

Define the term hardy, half hardy and tender

State the RHS hardiness zones for hardy, half-hardy and tender plants

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General Plant Parts:

Complete the labels for this plant:

A

B

C

D

E

F

G

H

Click to reveal answers A: Leaf/lamina B: internode C: Tap root D: Lateral root E: Growing tip/terminal bud/apical bud F: Petiole G: Node H: Axillary bud

State the function of A High surface area to maximise light interception for photosynthesis

State the function of B Contains xylem and phloem to transport water, minerals and sap. Increases height of plant

State the function of C Absorbs water and minerals. Helps to anchor the plant.

State the function of D Absorbs water and minerals. Helps to anchor the plant.

State the function of E Point from which new stem growth arises; contains meristem with constantly dividing cells

State the function of F Positions a leaf in the optimum position to intercept light, which increases photosynthesis

State the function of G Area of plant stem to which leaves attach. Contains axillary buds.

State the function of H A dormant bud that can give rise to new shoots

Flowers:

Define the term: petal (usually) colourful structure that attracts pollinators

Define the term: tepals monocotyledon flowers: petals and sepals are indistinguishable and referred to as tepals

Define the term: corolla collective term for petals

Define the term: perianth includes both the corolla and calyx

Define the term: corona When petals are fused to form a tubular flower

Define the term: receptacle holds all the flower parts

Define the term: sepals protective function, usually green; not always present

Define the term: pedicel flower stalk (ending with the receptacle)

Define the term: calyx collective term for sepals

Define the term: peduncle Stem holding many flowers

Complete the labels for this generalised flower:

A

B

C

D

Click to reveal answers A - D A: Petal (eudicotyledon) or tepal (monocotyledon) B: Sepal (eudicotyledon only) C: Receptacle D: Pedicel

I

L

E

F

G

H

J

K

Click to reveal answers E - L E: Stigma F: Style G: Ovary H: Ovule I: Carpel J: Anther K: Filament L: Stamen

What is the stigma's function? Receives pollen

What is the style's function? Holds the stigma in the optimum position to receive pollen

What is the ovary's function? Contains the ovules, which become the seed. Location of fertilisation

What is the anther's function? Produces pollen

What is the filament's function? Holds the anthers in optimum position to disperse pollen, e.g. via contact with a pollinating insect

Each number relates to a specific word, so if you think (1)________ is 'bananas' then if (1)________ appears later on in the passage, 'bananas' is the missing word.

Monocotyledon flowers have (1)_________ in multiples of (2)_________ whereas eudicotyledon flowers have (3)_________ in multiples of (4)_________. Monocotyledons have pollen with (5)_________ pore/furrow(s) whereas eudicotyledons have pollen with (2)_________ pore/furrow(s).

Hint: the missing words in a random order one, tepals, three, petals, four or five

Extra Hint: (1) tepals

Extra Hint: (2) three

Extra Hint: (3) petals

Extra Hint: (4) four or five

Extra Hint: (5) one

What term is given to a species that has separate male and female plants? Dioecious

What floral structures do male flowers have?

What term is given to a species with separate male and female flowers on the same plant? Monoecious

What floral structures do female flowers have?

What term is given to a species that has male and female parts within the same flower? Bisexual/ hermaphrodite/ perfect

What is cross-pollination?

1. What are each of these inflorescence structures called? (A - G)

2. What are structures H - K called?

A

B

C

H

I

D

E

F

G

J

K

Click to reveal answers A - G A: Spike B: Raceme C: Panicle D: Capitulum E: Simple umbel F: Compound umbel G: Corymb

Click to reveal answers H - K H: Disk floret I: Ray floret J: Pedicel K: Peduncle

Leaves:

Name the leaf arrangements:

A

B

C

Click to reveal answers A - C A: Alternate B: Opposite C: Whorled

Name the leaf margins:

1

2

3

4

Click to reveal answers 1 - 4 1. Entire 2. Serrate 3. Dentate 4. Lobed

Name the leaf shapes:

A

B

C

D

E

F

G

H

I

Click to reveal answers A - I A: Lanceolate B: Linear C: Ovate D: Deltoid E: Spear shaped F: Pinnatisect G: Palmate H: Digitate I: Pinnate

Name the leaf structures:

A

B

C

Click to reveal answers A - C A: lamina B: mid-rib C: petiole

State the differences in leaf venation between leaf A and B

Name the two major plant groups that leaf A and B represent

Name the vessels that plant veins contain
State the function of each vessel

A

B

Roots:

What type of root system is this?
What major plant group does this represent?
What are the main morphological features of this root system?

What type of root system is this?
What major plant group does this represent?
What are the main morphological features of this root system?

Compare the two root systems shown in the diagrams

Tap root systems have a primary root whereas fibrous root systems do not have a primary root.
Primary roots in tap root systems are derived from the radicle whereas fibrous roots are not derived from the radicle.
Tap roots' diameter is not fixed and they can thicken as they age. Fibrous roots have a fixed diameter at maturity.
Tap roots can undergo secondary thickening in woody plants (but not in herbaceous eudicots) whereas fibrous roots do not undergo secondary thickening.
Both tap roots and fibrous roots function to absorb water and minerals, and anchor plants into the soil.

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Leaves:

Name the leaf structures:

A

B

C

D

E

F

G

H

I

J

Click to reveal answers A - J A: Waxy cuticle B: Upper epidermis C: Palisade mesophyll layer D: Vein (containing xylem and phloem) E: Spongy mesophyll layer F: Air space G: Lower epidermis H: Waxy cuticle I: Guard cell J: Stoma (plural: stomata)

What is the function of A? The waxy cuticle helps to waterproof the leaf, reducing water loss. It protects the leaf from pests and pathogens.

What is the function of B? The upper epidermis secretes the waxy cuticle. It's transparent to allow light through.

What is the function of C? Palisade mesophyll cells are packed with chloroplasts, which undertake photosynthesis to produce glucose for the plant.

What is the function of D? Leaf vein containing xylem and phloem, which transport substances to and from the leaf.

What is the function of E? The spongy mesophyll is loosely packed and full of airspaces to facilitate gas exchange.

What is the function of F? Air spaces within which gasses diffuse, bringing carbon dioxide into contact with spongy mesophyll cells.

What is the function of G? The lower epidermis secretes the waxy cuticle. It's transparent to allow light through.

What is the function of H? The waxy cuticle helps to waterproof the leaf, reducing water loss. It protects the leaf from pests and pathogens.

What is the function of I? Guard cells control the opening and closing of a stoma.

What is the function of J? A stoma is a pore allowing gasses to diffuse in/out of the leaf, including carbon dioxide to enter for photosynthesis. The plural of stoma is stomata.

Stems:

Monocotyledon or Eudicotyledon stem? Eudicotyledon stem cross-section

A

B

C

D

E

F

G

Click to reveal answers A - G A: phloem B: cambium C: xylem D: cortex E: Vascular bundle F: pith G: epidermis

Monocotyledon or Eudicotyledon stem? Monocotyledon stem cross-section

1

2

3

4

5

Click to reveal answers 1 - 5 1: vascular bundle 2: cortex 3: epidermis 4: xylem 5: phloem

Each number relates to a specific word, so if you think (1)________ is 'bananas' then if (1)________ appears later on in the passage, 'bananas' is the missing word.

Eudicotyledon and monocotyledon stems both have (1)_______ but only eudicotyledon's (1)_______ have a (2)_______ layer. In eudicotyledons the (1)_______ are arranged in a (3)_______, whereas in monocotyledon stems they are (4)_______ through the stem. Both eudicotyledon and monocotyledon stems have (5)_______ tissue but only eudicotyledons have a (6)_______. Both eudicotyledons and monocotyledons have an outer layer of cells called the (7)_______, which secretes a (8)_______ ________ layer.

Eudicotyledon and monocotyledon stems both have (1)vascular bundles but only eudicotyledon's (1)vascular bundles have a (2)cambium layer. In eudicotyledons the (1)vascular bundles are arranged in a (3)ring, whereas in monocotyledon stems they are (4)scattered through the stem. Both eudicotyledon and monocotyledon stems have (5)cortex tissue but only eudicotyledons have a (6)pith. Both eudicotyledons and monocotyledons have an outer layer of cells called the (7)epidermis, which secretes a (8)waxy cuticle layer.

Hint: the missing words in a random order scattered, pith, epidermis, vascular bundles, waxy cuticle, ring, cortex, cambium

Extra Hint: (1) vascular bundles

Extra Hint: (2) cambium

Extra Hint: (3) ring

Extra Hint: (4) scattered

Extra Hint: (5) cortex

Extra Hint: (6) pith

Extra Hint: (7) epidermis

Extra Hint: (8) waxy cuticle

What is the xylem's function? Transports water and minerals from the roots to above ground parts. In woody plants it becomes lignified, strengthening the stem

What is the phloem's function? Transports sap (which contains sugars, hormones, minerals, salts, water) around the plant

What is the cambium's function? Contains meristem tissue that continuously divides. In vascular bundles these cells differentiate into new xylem and phloem cells

What's the vascular bundle's function? Produces and contains xylem and phloem

What is the cortex's function? Loosely packed with parenchyma cells, which gives strength to the stem. Green stems' cortex contain chloroplasts and undertake photosynthesis

What is the pith's function? Parenchyma cells that form 'packing tissue', adding strength to the stem. They can also store carbohydrates, an energy reserve for the plant

What's the epidermis' function? Transparent, tightly packed layer of cells around the outside of the stem. Secretes the waxy cuticle, which waterproofs the stem to reduce water loss. It also helps protects the stem from pests and pathogens.

Roots:

Monocotyledon or Eudicotyledon root? Monocotyledon root cross-section

Monocotyledon or Eudicotyledon root? Eudicotyledon root cross-section This is a young eudicot root

I

H

Click to reveal answers A - J A: Root hair B: Epidermis C: Cortex D: Endodermis E: Pericycle F: Xylem G: Phloem H: Stele I: Pith J: Vascular cambium

A

B

C

D

E

F

G

H

J

What are the differences between the monocotyledon and eudicotyledon root structures shown in the diagrams above?

What is the function of A? High surface area to maximise uptake of water and minerals from the soil

What is the function of B? Tightly packed surface layer that helps to prevent entry of pests and pathogens

What is the function of C? Packed with parenchyma cells that give structure to the root. They can store water and carbohydrates

What is the function of D? Contains the Casparian strip: a waterproof layer that forces water between cortex cells to cross the cell membrane

What is the function of E? Layer within the endodermis that contains meristematic tissue which produces lateral roots

What is the function of F? Xylem transport water and minerals from the roots to the above ground parts

What is the function of G? Phloem transport sap around the plant. Sap contains sugars, hormones, minerals, water

What is the function of H? Contains the xylem and phloem vessels

What is the function of I? The pith stores nutrients, including starch. Starch is a carbohydrate, which is an energy store

What is the function of J? Contains meristem that continuously divides to form new xylem and phloem

Longitudinal cross-section through a young root:

A

B

C

D

E

F

G

H

1

2

3

Click to reveal answers A - H A: Epidermis B: Root hair C: Cortex D: Endodermis E: Pericycle F: Stele G: Apical meristem H: Root cap

Click to reveal answers 1 - 3 1: zone of differentiation 2: zone of elongation 3: root tip

What is the function of part G? Contains undifferentiated cells that continuously divide, allowing the roots to grow

What is the function of part H? Made of dead cells that protect the apical meristem tissue as the growing root pushes through the soil

What is the function of parts 1 - 3? 1. Zone where root cells differentiate and become specialised in their function. This zone has many root hairs and plays a key role in absorption of water and minerals. There is no waxy cuticle so water can be absorbed freely. 2. The cells in this zone grow longer, which pushes the root tip forward through the soil. 3. The root tip contains meristem tissue from which new root cells are derived. It also has a protective structure in the root cap, which is made of dead cells that protects the apical meristem tissue.

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What is pollination? Pollination is the transference of pollen from a anther to a stigma.

What is the benefit of cross-pollination? Cross-pollination maximises the genetic diversity of seeds because genes from pollen (male) mix with genes in the ovule (female). Increased genetic diversity in the seeds and eventual offspring plants means some individuals are more likely to have adaptations that are better suited to their environment, and therefore survive. This is part of the theory of natural selection proposed by Charles Darwin.

What is cross-pollination? Cross-pollination is when pollen from the anther of one plant is transferred to the stigma of a different plant.

What are vectors cross-pollination? A vector transfers something. Pollen is transferred by three types of vector: animal (insects in the UK), wind and water. In the UK insects undertake pollination. In other countries birds, mammals and other organisms also pollinate flowers. Wind pollinated flowers rely on air currents to transfer pollen from anther to stigma. A small number of aquatic plants are water pollinated, where water currents transfer pollen from anther to stigma.

What is self-pollination? Self-pollination is when pollen is transferred from the anther to the a stigma of the same plant (i.e. the plant pollinates itself)

Why don't plants just self-pollinate? Self-pollination results in a reduced genetic diversity in the offspring. This means the offspring have less genetic diversity than those arising from cross-pollination, and therefore less variation in their characteristics. This means fewer will have adaptations that are advantageous for survival in their environment. However, some plants have flowers that will self-pollinate if they aren't cross-pollinated; this happens at the end of the flower's life. In this instance, seeds from self-pollination is better than no seeds at all.

What is the vector of pollination for this flower?

How is the inflorescence positioned for pollination?

How are flowers generally adapted for this type of pollination?

This flower has:

Brightly coloured petals to attract pollinators
Nectaries at the base of the flowers
Fragrance can be produced to attract pollinators
There are guidelines on the petals (visible to insects that can see UV light) direct pollinators to nectaries
Large petals act as a landing pad for insects
Stigma and stamens are held in a position to maximise transference of pollen, as well as being robust to withstand being bushed against by pollinators
Pollen is large and sticky to attach to pollinators' bodies

A

B

A and B are flowers on the same plant. What is their vector of pollination?

What is the difference between the flowers in A and B?

How are these flowers positioned and adapted for this type of pollination?

Positioning:

The male flowers are positioned high on the plant where their pollen is released into the wind where wind currents are stronger above the plant.

The female flowers are positioned lower on the plant to maximise their chance of pollen-laden winds carrying pollen from nearby plants.

Flower adaptations for wind pollination:

Anthers produce a large amount of small/lightweight pollen
Anthers protrude outside of the flower to maximise exposure to wind
Stigma protrudes outside of flower to maximise exposure to wind
Stigma is sticky so pollen sticks to it
Stigma is has a high surface area (they are often 'feathery') to maximise exposure to the air and therefore wind-blown pollen
Petals and sepals (eudicotyledons), or tepals (monocotyledons), are reduced and dull in colour, or absent
Nectaries are absent

1

2

3

Name parts 1 - 3 1. Pollen grain 2. Pollen tube 3. Ovule

What happens after pollen lands on the stigma, before fertilisation? The tube nucleus grows a pollen tube down the style and into the ovary, connecting with an ovule. The generative nucleus then moves down the pollen tube toward the ovule. During this process it divides into two nuclei

Describe the process of fertilisation

Fertilisation occurs when the two nuclei derived from the generative nucleus enter the ovule.

- One of the male nuclei fuses with the female gamete, forming a zygote (a fertilised egg).

- The other nuclei derived from the generative nucleus fuses with the two polar nuclei in the ovule; this will form the endosperm, a food source for the developing embryo.

This process is called double fertilisation and only occurs in angiosperms.

What is the difference between hermaphrodite, monoecious and dioecious flowers?

Hermaphrodite: (aka bisexual or perfect flowers)

These produce both male (stamens) and female (carpel) in the same flower.

Monoecious:

These are plants that produce separate male and female flowers on the same plant.

Dioecious:

These are plants that have separate male and female plants. Male plants have flowers that only produce stamens; male plants cannot produce fruit/seed. Female plants have flowers that only produce carpels; female plants produce the fruits/seeds.

Describe the strategies to avoid self-pollination

Dioecious plants cannot pollinate themselves because male and female plants are genetically different, ensuring cross-pollination.

Monoecious plants have separate male and female flowers, meaning anthers are physically distanced from stigmas. This reduces the risk of self-pollination.

In hemaphrodite/bisexual/perfect flowers:

Protogyny: where the stigma matures before the anthers, thereby increasing likelihood pollen from another individual of the same species lands on the stigma.

Protandry: where the anthers mature before the stigma; the anthers will have shed their pollen before the stigma becomes receptive to pollen, decreasing risk of self-pollination.

Up

Where does photosynthesis happen?
What is the chemical formula for photosynthesis?
Why is photosynthesis important?
What are the limiting factors to photosynthesis?
How can the rate of photosynthesis be increased in a greenhouse?

1. Where does photosynthesis happen?

In the green parts of a plant, including leaves and stems. Photosynthesis happens within the chloroplasts of cells.

2. What is the chemical formula for photosynthesis?

(in the presence of light and chlorophyll)

Water + carbon dioxide ----------> glucose + oxygen

3. Why is photosynthesis important?

It transfers light energy (usually from the sun) to chemical energy in the form of glucose (a sugar). Glucose is a high energy molecule that's broken down in respiration, which powers all cell processes.

4. What are the limiting factors to photosynthesis?

Suitable temperature, light intensity, carbon dioxide concentration.

Water is not a significant limiting factor as if it's in short supply then stomata will close preventing carbon dioxide entry to the leaf, which prevents photosynthesis occurring. This happens before water concentration would become a limiting factor to photosynthesis.

5. How can the rate of photosynthesis be increased in a greenhouse?

- Maintain an optimum temperature for photosynthesis by heating or ventilating.

- Artificially increase carbon dioxide concentration (best when vents are closed)

- Increase light intensity and/or duration via artificial lighting

- Ensure an adequate supply of water and nutrients to plant roots

Where does respiration happen?
What are the two types of respiration?
What is the chemical formula for each type of respiration?
Why is respiration important?

1. Where does respiration happen?

In all plant cells, in the mitochondria

2. What are the two types of respiration?

Aerobic respiration (with oxygen) and anaerobic respiration (without oxygen)

3. What is the chemical formula for each type of respiration?

Aerobic respiration:

Glucose + oxygen --> energy + carbon dioxide + water

Anaerobic respiration:

Glucose --> (low yield of) energy + ethanol

4. Why is respiration important?

Respiration releases energy which is used to power all plant processes.

Each number relates to a specific word, so if you think (1)________ is 'bananas' then if (1)________ appears later on in the passage, 'bananas' is the missing word.

Organisms, such as plants and green algae use (1)__________ energy to convert (2)__________ and water into (3)__________ and oxygen. The useful product of photosynthesis is (3)__________. Only (4)__________ parts of a plant undertake photosynthesis. They're (4)__________ because these parts contain (5)__________, which contain a (4)__________ pigment called (6)__________ that absorbs (1)__________ energy.

(3)__________ is used in a chemical reaction called (7)__________. (8)__________ (7)__________ occurs when there is (9)__________ available. This results in a high yield of (10)__________ from the (3) __________ molecule. If (9)__________ is not available, for example in (11)__________ soil, then (12)__________ (7)__________ occurs. This results in a (13)__________ yield of (10)__________ and the toxic byproduct (14)__________.

Organisms, such as plants and green algae use (1) light energy to convert (2) carbon dioxide and water into (3) glucose and oxygen. The useful product of photosynthesis is (3) glucose. Only (4) green parts of a plant undertake photosynthesis. They're (4) green because these parts contain (5) chloroplasts, which contain a (4) green pigment called (6) chlorophyll that absorbs (1) light energy.

(3) Glucose is used in a chemical reaction called (7) respiration. (8) aerobic (7) respiration occurs when there is (9) oxygen available. This results in a high yield of (10) energy from the (3) glucose molecule. If (9) oxygen is not available, for example in (11) waterlogged soil, then (12) anaerobic (7) respiration occurs. This results in a (13) low yield of (10) energy and the toxic byproduct (14) ethanol.

Hint: the missing words in a random order green, waterlogged, carbon dioxide, energy, chlorophyll, oxygen, light, ethanol, anaerobic, aerobic, chloroplasts, glucose, low, respiration

Extra Hint: (1) light

Extra Hint: (2) carbon dioxide

Extra Hint: (3) glucose

Extra Hint: (4) green

Extra Hint: (5) chloroplasts

Extra Hint: (6) chlorophyll

Extra Hint: (7) respiration

Extra Hint: (8) aerobic

Extra Hint: (9) oxygen

Extra Hint: (10) energy

Extra Hint: (11) waterlogged

Extra Hint: (12) anaerobic

Extra Hint: (13) low

Extra Hint: (14) ethanol

7. Water Movement Through the Plant

Up

Water movement into a root:

A

B

C

D

E

Click to reveal answers A - E A: Root hair B: water entry via symplastic route C: water entry via apoplastic route D: Casparian strip E: Xylem

How is structure A adapted to its function? This is a root hair which has a high surface area to absorb water and minerals from the soil.

Each number relates to a specific word, so if you think (1)________ is 'bananas' then if (1)________ appears later on in the passage, 'bananas' is the missing word.

Water enters plant cells via a process called (1)__________. (1)__________ is the movement of water from an area of (2)__________ water concentration to an area of (3)__________ water concentration across a (4)__________ ________ membrane. It is a (5)__________ process, meaning it does not require (6)__________.

Water enters roots via (7)__________ routes. One is the (8)__________ route where water enters root cells through the (9)__________ __________ via (1)__________. Water can also enter roots via the (10)__________ route. This is where water travels between (11)__________ by travelling along (12)__________ __________. Water takes this route until it reaches the (13)__________ __________. This is a (14)__________ layer that prevents water travelling further via the (10)__________ route. At this point water is forced to enter via the (8)__________ route, through the (9)__________ __________ via (1)__________.

Water then enters the root's (15)__________ and moves upward toward the stems and leaves. Three main factors enable water to move against gravity within the (15)__________:

(16)__________ __________ is caused by the continual entry of water into the root cells via (1)__________. This forces water into the root's (15)__________ and pushes water further into the plant.
(17) __________ __________, which is the attraction of water to the sides of the (15)__________ due to water's (18)__________ properties.
(19)__________ pull, where by water vapour exits the stomata via (19)__________. Due to water's (20)__________ properties, more water is 'pulled' up the (15)__________ to replace that lost via (19).

(19)__________ is essential for continuous supply of nutrition to a plant via dissolved (21)__________ in the water within xylem. As long as (19)__________ is happening, new (21)__________ enter plant cells, enabling growth and repair of cells.

Water enters plant cells via a process called (1) osmosis. (1) osmosis is the movement of water from an area of (2) high water concentration to an area of (3) low water concentration across a (4) semi/partially permeable membrane. It is a (5) passive process, meaning it does not require (6) energy.

Water enters roots via (7) two routes. One is the (8) symplastic route where water enters root cells through the (9) cell membrane via (1) osmosis. Water can also enter roots via the (10) apoplastic route. This is where water travels between (11) cells by travelling along (12) cell walls. Water takes this route until it reaches the (13) Casparian strip. This is a (14) waterproof layer that prevents water travelling further via the (10) apoplastic route. At this point water is forced to enter via the (8) symplastic route, through the (9) cell membrane via (1) osmosis.

Water then enters the root's (15) xylem and moves upward toward the stems and leaves. Three main factors enable water to move against gravity within the (15) xylem:

(16) Root pressure is caused by the continual entry of water into the root cells via (1) osmosis. This forces water into the root's (15) xylem and pushes water further into the plant.
(17) Capillary action, which is the attraction of water to the sides of the (15) xylem due to water's (18) adhesive properties.
(19) Transpiration pull, where by water vapour exits the stomata via (19) transpiration. Due to water's (20) cohesive properties, more water is 'pulled' up the (15) xylem to replace that lost via (19) transpiration.

(19) transpiration is essential for a continuous supply of nutrition to a plant via dissolved (21) minerals in the water within xylem. As long as (19) transpiration is happening, new (21) minerals enter plant cells, enabling growth and repair of cells.

Hint: the missing words in a random order xylem, semi/partially, Casparian, energy, cell membrane, osmosis, transpiration, apoplastic, root pressure, high, minerals, capillary action, low, symplastic, waterproof, cells, cohesive, two, cell walls, adhesive, passive

Extra Hint: (1) osmosis

Extra Hint: (2) high

Extra Hint: (3) low

Extra Hint: (4) semi/partially permeable

Extra Hint: (5) passive

Extra Hint: (6) energy

Extra Hint: (7) two

Extra Hint: (8) symplastic

Extra Hint: (9) cell membrane

Extra Hint: (10) apoplastic

Extra Hint: (11) cells

Extra Hint: (12) cell walls

Extra Hint: (13) Casparian

Extra Hint: (14) waterproof

Extra Hint: (15) xylem

Extra Hint: (16) root pressure

Extra Hint: (17) capillary action

Extra Hint: (18) adhesive

Extra Hint: (19) transpiration

Extra Hint: (20) cohesive

Extra Hint: (21) minerals

A

B

What do A and B represent? A represents the entry of water into a root hair cell B represents the entry of minerals into a root hair cell

How do A and B differ? A, the entry of water, is via osmosis - a passive process (does not require energy. Water moves from a higher water concentration outside the cell to a lower concentration inside the cell across the semi-permeable cell membrane. B, the entry of minerals, requires energy. Minerals move from a lower concentration outside the cell to a higher concentration inside the cell. The cell uses energy from respiration to undertake active transport, which moves the mineral ions into the cell.

What happens to A and B if roots are in waterlogged soil? Process A, osmosis, continues as normal. The cell cannot control osmosis (the movement of water into or out of a cell) Process B, active transport, requires energy from respiration. In waterlogged soils there is very low oxygen availability, meaning aerobic respiration stops. Only anaerobic respiration can occur. This has a low yield of energy and so fewer mineral ions can be actively transported into the root cells, potentially leading to nutrient deficiency in the whole plant. A byproduct of anaerobic respiration is ethanol, which is toxic and harms the root cells. Eventually root cells die, meaning neither water or minerals enter the roots. At this point plants begin to wilt despite abundant water in the soil.

B

C

A

Name the route through which water enters root cells at point A
Define your answer to question 1
Name the structure that transports water from point A to point B
What else (other than water) travels through this structure?
Name the process occurring at point C
What structures that allow the process named in question 6 to occur?
State the mechanisms through which water can travel from point A to point B
Describe what causes a change to process C if there is a water shortage at the roots
Describe the benefits of ensuring plants have sufficient water and oxygen in the root zone

1. Name the route through which water enters root cells at point A

Osmosis

2. Define your answer to question 1

Osmosis is the movement of water from an area of high water concentration to an area of low water concentration across a semi-permeable ('partially-permeable' is an acceptable synonym) membrane. It is a passive process.

3. Name the structure that transports water from point A to point B

Xylem

4. What else (other than water) travels through this structure?

Minerals (dissolved in water)

5. Name the process occurring at point C

Transpiration

6. What structures allow the process named in question 6 to occur?

Two guard cells create an opening in the epidermis called a stoma

7. State the mechanisms through which water can travel from point A to point B

Root pressure due to water continuously entering via osmosis forces water from point A toward point B. Capillary action due to water's adhesive properties aids water movement up the xylem. Transpiration pull is the most significant factor. Water's cohesive nature means water lost via transpiration exerts a 'pull' on water in the plant, drawing water up the xylem to replace water vapour lost from the leaves.

8. Describe what causes a change to process C if there is a water shortage at the roots

The guard cells will change shape to close the stomata. This will prevent transpiration occurring.

9. Describe the benefits of ensuring plants have sufficient water and oxygen in the root zone

Sufficient water at the roots means water will continuously enter the root cells via osmosis, replenishing the transpiration stream to ensure the plant does not suffer a net loss of water. This also means minerals are continually transported into plant cells via the transpiration stream, enabling healthy growth and repair of cells.

Sufficient oxygen at the roots means aerobic respiration can occur in root cells. This ensures there is sufficient energy for cell processes, including growth, repair and active transport of mineral ions into root cells from the soil.

What benefits does process C bring to urban environments where mature street trees are present?

Transpiration results in a net cooling of the surrounding urban environment. This is a benefit in hot summer weather where the urban heat island effect can cause urban areas to become hotter than surrounding countryside, increasing risk to urban people's health. Mature trees undertake a large amount of transpiration in hot weather, improving urban cooling and lowering the risk of extreme heat to people's health.

1

2

3

4

5

What is happening at point 1? Water crosses the cell membrane via osmosis

What is happening at point 2? Water gathers on the cell's surface

What is happening at point 3? Water on the cell surfaces has evaporated into the leaf's air spaces. The concentration of water vapour inside the leaf's air spaces increases

What is happening at point 4? Water vapour diffuses out of the leaf's stomatal openings from the higher water vapour concentration inside the leaf to the lower water vapour concentration outside the leaf. This is transpiration.

What is happening at point 5? Water vapour has diffused out of the leaf - this is transpiration. Water vapour continues to spread out into the air surrounding the leaf, increasing humidity.

What factors affect the rate of transpiration? Wind speed Temperature Relative humidity Soil moisture Light

The rate of transpiration is different in diagrams A and B.

Name the factor causing a difference in the rate of transpiration
Name one distinct ecosystem each for A and B that is typical of conditions shown in the diagrams
Which situation, A or B, would have the higher rate of transpiration?
Explain your answer to question 3.
Describe the ways that transpiration could be increased in both situations

1. Name the factor causing a difference in the rate of transpiration

Relative humidity

2. Name one distinct ecosystem each for A and B that is typical of conditions shown in the diagrams

A: desert, tundra (these are low humidity environments)

B: tropical rainforest, temperate rainforest (these are high humidity environments)

3. Which situation, A or B, would have the higher rate of transpiration?

A would have a higher rate of transpiration

4. Explain your answer to question 3.

External humidity in A is lower than in B, meaning there is a greater difference in the concentration of water vapour inside and outside the leaf in A. This means there is a steeper concentration gradient so water vapour will diffuse out of the leaf at a greater rate in A than in B.

5. Describe the ways that transpiration could be increased in both situations

Increasing temperature or increasing windspeed.

A

B

Each number relates to a specific word, so if you think (1)________ is 'bananas' then if (1)________ appears later on in the passage, 'bananas' is the missing word.

The (1)________ of transpiration can change depending on (2)________ conditions. If there is a lack of soil (3)________ then (4)________ will close due to a change in the (5)________ of the guard cells. Closed (4)________ means that (6)________ ________ does not exit the leaf, preventing water loss. The disadvantage of this is that (7)________ ________ cannot enter the leaf, preventing (8)________ from occurring if (9)________ is present.

Assuming there is sufficient soil (3)________ the (4)________ will remain open, in most plants, during daylight hours. The (1)________ of transpiration will vary depending on other (2)________ factors:

If the (10)________ speed increases, external humidity around the stomata will (11)________. This causes a difference in (12)________ humidity inside and outside the leaf. The (13)________ humidity outside the leaf means the (1)________ of (14)________ of water vapour from inside the leaf to outside the leaf, through the (4)________, is (15)________. Therefore, higher (10)________ speed (16)________ the (1)________ of transpiration.
An increase in (17)________, for example through the course of a summer day, (16)________ the (1)________ of transpiration. This is because particles of water in water vapour move (15)________ at a higher (17)________, which increases the (1)________ of (14)________ of water vapour from inside the leaf to outside the leaf. Therefore, a higher (17)________ (16)________ the (1)________ of transpiration.

The (1) rate of transpiration can change depending on (2) environmental conditions. If there is a lack of soil (3) water then (4) stomata will close due to a change in the (5) shape of the guard cells. Closed (4) stomata means that (6) water vapour does not exit the leaf, preventing water loss. The disadvantage of this is that (7) carbon dioxide cannot enter the leaf, preventing (8) photosynthesis from occurring if (9) light is present.

Assuming there is sufficient soil (3) water the (4) stomata will remain open, in most plants, during daylight hours. The (1) rate of transpiration will vary depending on other (2) environmental factors:

If the (10) wind speed increases, external humidity around the stomata will (11) decrease. This causes a difference in (12) relative humidity inside and outside the leaf. The (13) lower humidity outside the leaf means the (1) rate of (14) diffusion of water vapour from inside the leaf to outside the leaf, through the (4) stomata, is (15) faster. Therefore, higher (10) wind speed (16) increases the (1) rate of transpiration.
An increase in (17) temperature, for example through the course of a summer day, (16) increases the (1) rate of transpiration. This is because particles of water in water vapour move (15) faster at a higher (17) temperature, which increases the (1) rate of (14) diffusion of water vapour from inside the leaf to outside the leaf. Therefore, a higher (17) temperature (16) increases the (1) rate of transpiration.

Hint: the missing words in a random order temperature, stomata, photosynthesis, environmental, wind, lower, rate, increases, decrease, water, faster, shape, light, water, relative, carbon dioxide, faster, diffusion

Extra Hint: (1) rate

Extra Hint: (2) environmental

Extra Hint: (3) water

Extra Hint: (4) stomata

Extra Hint: (5) shape

Extra Hint: (6) water vapour

Extra Hint: (7) carbon dioxide

Extra Hint: (8) photosynthesis

Extra Hint: (9) light

Extra Hint: (10) wind

Extra Hint: (11) decrease

Extra Hint: (12) relative

Extra Hint: (13) lower

Extra Hint: (14) diffusion

Extra Hint: (15) faster

Extra Hint: (16) increases

Extra Hint: (17) temperature