Plant reproduction

What helps plants attract insects

Bright petals

Contain nectar

Stamen

Male part

Anther - Produce pollen

Fillament

Carpel

Female part

Stigma - pollen attaches

Ovary - Produces female gametes

Ovule - contains female gamete

Style - connect stigma to ovary

Pollination

Transfer of pollen fro anther to stigma

2 types of pollination and how

Self-pollination - Own pollen lands on own stigma

Cross-pollination - receive pollen from different plant of same species

What contain the male and female gametes

Male - pollen grain

Female - Ovules

What are the orange bits + describe pollen grain formation

Pollen sacs - Mother cells undergo meiosis t produce 4

Each one then mitoses to form pollen grain with generative and tube nucleus

How are female gametes produced

megaspore undergoes meiosis to produce 4 haploid cells

3 degenerate leaving 1 remaining

Mitoses 3 times to produce Embryo sac with 8 nuclei

What do the 8 nuclei become in the female embyro sac

2 synergids

1 Ovule

3 antipodal cells

2 free polar nuclei

Describe pollination

When pollen lands on the stigma - pollen tube nucleus controls growth of pollen tube

Generative nucleus undergoes mitosis to produce 2 sperm nuclei

Pollen tube make way to micropyle - tube nucleus degenerates

Micropyle

Entrance to ovule (bottom)

Describe fertilisation once sperm nucleus enter the micropyle

First one Fuses with egg cell to form zygote

Other one fuses with 2 free polar nuclei to make triploid endosperm

How does germination happen in monocotyledon

Water absorbed through micropyle

Gibberellin stimulates growth of aleurone layer

This causes amylase and maltase to be synthesised

these break down starch from endosperm to use glucose for respiration

Label A-D + function

Plumule - become first shoot

Radicle - become first root

Cotyledon - Food store

Seed coat

What 3 thing do you need for germination

O2

optimum temperature

water