plant reproduction

2 features that indicate a flower is wind pollinated

• stigmas large, feathery and outside petals

• petals small, not coloured brightly

• anthers outside petals

name the part of the carpel on which the pollen grain lands

stigma

list the contents of a mature pollen grain

• one tube nucleus

• two sperm nuclei

identify the part of the flower which develops into the seed

ovule

identify the part of the flower which develops into the fruit

fruit

pollination

the transfer of pollen from the anther to the stigma of a flower of the same species

self- pollination

the transfer of pollen from the anther to stigma on the same plant

cross-pollination

the transfer of pollen from the anther to a stigma on a different plant

adaption of flower that is wind-pollinated

• petals small, not coloured brightly

• anthers outside petals

• stigmas large, feathery and outside petals

describe main events of pollen grain development

• microspore mother cell (2n) are located in the pollen sacs

• they are diploid

• they divide by meiosis to produce a group of 4 haploid cells called a tetrad

• each tetrad breaks up to form 4 separate haploid pollen grains

• pollen grains divide by mitosis producing 2 haploid nuclei

• tube nucleus-forms the pollen tube

• generative nucleus- forms the male gametes

2 fertilizations occur during sexual reproduction in flowering plants
describe what happens during both of these fertilizations

• one male nucleus fuses with the egg and forms a diploid zygote

• one male nucleus fuses with the 2 polar nuclei and forms a triploid endosperm

what is a cotyledon

a seed leaf

function of cotyledon

• stores food

• absorbs food from endosperm

function of testa

protects the seed

function of plumule

develops into the young shoot

function of radicle

develops into the young root

give 2 methods of fruit and seed dispersal

• wind

• water

• animal

• self

function of petal

attract insects to the flower for pollination

function of anther

produces pollen

function of sepal

protects the flower and prevents it drying out

name a type of pollination other than by animals

wind pollination

two fertilisations occur following pollination, name the products of both fertilisations

diploid zygote

triploid endosperm

way in which seedless fruits can be produced

plant growth regulators

give an example of endospermic and non-endospermic seeds

endospermic-maize

non-endospermic-broad bean

2 advantages for a plant that reproduces by seed

• produces genetic variation

• seeds can be dispersed widely

• survive winter

2 advantages for a plant that reproduces by vegetative propagation

• more reliable

• cheap

• fast

why are fruits formed by plants

• to protect seeds

• aid seed dispersal

vegetative propagation

asexual reproduction in a plant

name any 2 methods of vegetative propagation used by plants and for each method give an example of a plant that carries out that method

stem- strawberry

root-dahlia

bud-onion

leaf-mother of thousands

name 3 methods horticulturist may use to artificially propagate plants

cutting

layering

grafting

micro-propagation

which part of the embryo in a germinating seed give rise to the root

radicle

which part of the embryo in a germinating seed give rise to the shoot

plumule

what way can pollen be carried to the stigma of a flower

wind

water

animals

describe how the generative nucleus gives rise to the male gametes

generative nucleus divides by mitosis

give an account of the development of the egg cell within the ovule

• the megaspore mother cell (2n) divides by meiosis to form 4 haploid cells

• 3 of these cells die

• the remaining cell is called the embryo sac

• the nucleus of the embryo sac divides by mitosis three tines forming 8 haploid nuclei

• 5 of these nuclei will later die remaining 3 are the gametes

• 2 of these form the polar nuclei in the embryo sac

• the remaining female gamete forms an egg cell

state the collective term used to describe the anther and filament of the flower

stamen

describe the main events that occur immediately after pollination

• pollen grain germinates and produces pollen tube

• the tube nucleus digests through the style

• generative nucleus divides by mitosis to form 2 haploid make nuclei gametes and enters the embryo sac

• 1 haploid male fuses with the haploid egg to form the diploid zygote

• the 2nd haploid male nucleus fuses with the 2 haploid polar nuclei to form a triploid endosperm

state the location where food is usually stored in a monocot seed

endosperm

state the location where food is usually stored in a dicot seed

cotyledon

describe how seeds contribute to the formation of fruit

produce plant growth regulators

name a part of a flower from which a fruit may develop

ovary

role of genetics in fruit production

seedless fruits

role of digestion in gemrination

stored food in endosperm and cotyledon

role of respiration in germination

produces ATP to drive cell division

give an example of asexual reproduction in flowering plants

runners-strawberry

when investigating the effect of water, oxygen and temperature on germination

how did you deprive the seeds of oxygen

add water that has been strongly boiled for 5 minutes and left to cool

add a layer of oil to prevent oxygen re-entering

when demonstrating the digestive activity of germinating seeds
what type of agar did you use

starch

name 2 ways cross-pollination can occur in flowering plants

• animal

• wind

• water

what happens to the generative nucleus following pollination

divides by mitosis

forms the male gametes

the human defence system can react against pollen causing respiratory symptoms such as sneezing and watery eyes

what is this reactions commonly known as

hayfever

2 advanatages of sexual reproduction over asexual reproduction in plants

• variation

• less disease

which type of cell division occurs during production of female gametes in flowering plants and humans

meiosis

give the precise location of the production of female gametes in humans and in flowering plants

flowering plants-embryo sac

humans- graafian follicle

give the precise location of fertilisation under normal circumstances in humans and in flowering plants

flowering plants-embryo sac

humans-oviduct

name the next stage of development following formation of the zygote in humans and in flowering plants

flowering plants-embryo

humans-morula

give an advantage and disadvantage of sexual reproduction

advantage-increased variation

disadvantage-requires 2 parents

2 features of vegetative propagation

• no gametes

• one parent

• no variation

give an example of natural vegetative propagation from a leaf and an example from a bud

• leaf-mother of thousands

• bud-onion

following fertlisation, from which part of the flower is the seed formed

ovule

monocotyledonous

one seed leaf

name the site of production of pollen grain

anther

name the structure on which pollen grain must land to complete pollination

stigma

many species have mechanism,s that prevent self-pollination, how could plants benefit from this

greater variation

which part of a flower usually develops into a fruit

ovary

name a structure through which the pollen tube grows in order to reach the embryo sac

stigma

within the pollen tube the generative nucleus divides to form two male gametes

what type of division takes place

mitosis

within the pollen tube the generative nucleus divides to form two male gametes

with what does each male gamete fuse in the embryo sac?

egg and polar nuclei

within the pollen tube the generative nucleus divides to form two male gametes

name the product of each fusion

zygote

endosperm

as the seed forms following fertilisation a food store develops in one of two structure, name these structures

endosperm

fertilsation

formation of zygote

from what structure in the carpel does the seed develop

ovule

the embryo plant within the seed has a number of plants list 2 parts of give their roles

radicle- develops root

plumule-develops shoot

role of ovary

contains ovules

the 2 male gametes in the pollen tube are derived from the generative nucleus

do these gametes forma s a result of mitosis or meiosis

mitosis- 2 daughter cells produced

fate of each of the male gametes

• one fuses with the egg

• one fuses with the endosperm nucleus or polar nuclei