D3.1 Reproduction

describe angiosperms

• flowering plants, category in the plant kingdom

• have flowers as reproductive structures

• either unisexual or hermaphroditic

describe flowers

• reproductive organs used by sperms

• to produce and transfer gametes between members of a species

draw and annotate structuers of a hermaphroditic flower

Outline pollination to gamete production in the flower

• pollen grain carried by wind or pollinators attack to the stigma

• pollen grain elngates a pollen tube down the style

• the male gamete travel down the pollen tube into hte ovary and ovule

• male gamete fertilise with female gamete in the ovary

pollination is a form of ___ ___

pollination is a form of sexual reproduction

gametes are produced through ___

gametes are produced through meiosis

state 3 basic steps of fertilisation

1. fetilisation

2. develops into embryo

3. within a seed

describe pollen transfer thorugh animals

• attract pollinators as flower are brightly clored, rich with nectar or emit a sweet aroma

describe pollen trnasfer through wind

• common for flowers of grasses or cereal crops

• common for small, unscented and nectar-lless flowers

• usually of dull apperance

why is self fertilisation not favoured?

• reduce genetic variability of hte population

• bree

state 3 mathods to prevent self fertilisation

1. stamens and stigma mature at diff times

2. anthers and stigma are anatomically distanced

3. only accept pollen from another individual in the species

describe self incompatibility

• inability of hermaphroditic flowers to produce zygotes after self pollination

• may occur during pollen germination, growth of the pollen tube, fertilisation

• aloe plants have incompatible genes → doesn’t recognise its own pollen → doesn’t allow fertilisation to occur

why must dispersion of seeds occur

the seed would otherwise compete with the parent plant for resources

describe 3 methods of seed dispersion

1. wind

• seeds are light, with adaptation such as wings or hair

• e.g. dandelion, maple

2. water

• seeds have buoyancy

• specialised structures or husks to help seeds float

• e.g. coconuts can survive 120 days afloat at sea

3. animals

• animals ingest fruits ahve seeds, then discard it

• or they consume the food and discard the seed in their faeces

• seeds can be stored and hidden over winter

• animal adaptations allow seeds to hitch a ride

• seeds may have burrs or velcro to stick to animal bodies

Outline 3 WOW conditions required for germination

1. water

• water absorbed by the micropyle

• cotyldon secretes plant growth substances (hormones and enzymes)

• water rehydrates seed during germination for metabolic processes to occur

2. oxygen

• for aerobic resp → for ATP

• ATP used for most metabolic events in germination

3. warmth

• 25-30 C

• enzymes optimal range, enzymes need for metabolism

• warmth required for SPRINGTIME germination as it warms up the seed after cold in the winter

Describe germination

• resumption of growth by an embryonic plant in seed or fruit

• only in ideal WOW conditions or else it is dormant

state 5 steps of germination

1. uptake of water

2. activation of hormones and enzymes

3. breakdown of starch to maltose in cotyledons

4. transport of maltose to embryo

5. maltose used to build structures and to provide E for aerobic resp

complete when the radicle (primary root) emerges