BY5.3 - Plant Reproduction

Question 0

Name and give the functions of the male reproductive organs of an angiosperm

Answer 0

Collective name: Stamen

1) Filament - supports the anther - contains PHLOEM TISSUE - supplies anther with sucrose and other organic molecules for POLLEN GRAIN FORMATION
2) Anther - Produces pollen grains - contain male gametes

Question 1

Name and give the functions of the female reproductive organs of an angiosperm:

Answer 1

Collective: Carpel

1) Ovary - contains OVULES - contain female gametes
2) Style - stalk structure
3) Stigma - surface receives pollen

Question 2

What is a receptacle?

Answer 2

Apex of the flower stalk

Question 3

What are sepals?

Answer 3

leaf - like structures which protect the flower in bud

Question 4

What is a corolla?

Answer 4

landing platform for insects

Question 5

How do petals attract insects?

Answer 5

• Brightly coloured
• Scented
• Have nectar

Question 6

What is pollination?

Answer 6

The transfer of pollen grains from the anther to the stigma of a plant of the same species

Question 7

What is Self-Pollination?

Answer 7

The transfer of pollen from the anthers to the stigma of the same flower/different flower of the same plant

Question 8

What is Cross-Pollination?

Answer 8

When pollen is transferred from the anther of one flower to the stigma of a flower on a different plant of the same species

Question 9

What is the difference in anthers between Insect and Wind Pollinated flowers?

Answer 9

Insect Pollinated : inside the Flower

Wind pollinated : Outside the flower so wind can blow pollen away

Question 10

What is the difference in Stigmas between Insect and Wind Pollinated flowers?

Answer 10

Insect pollinated: Inside the flower

Wind pollinated: large, feathery stigmas

• large surface area to catch pollen grains

Question 11

What is the difference in pollen grains between insect and wind pollinated plants?

Answer 11

Insect: small amount, sticky pollen

Wind: - large amount

- Small, smooth, light pollen

Question 12

What is the biological term for self-fertilisation?

Answer 12

Inbreeding

Question 13

What is the biological term for cross-fertilisation?

Answer 13

Outbreeding

Question 14

How is genetic variation generated in the genotypes of Self-fertilised species?

Answer 14

1) Random assortment / crossing over in meiosis
2) mutation

Question 15

What effect does Inbreeding have on the genotype of a plant species?

Answer 15

less genetic variation in genotype

Question 16

What is an advantage of Inbreeding?

Answer 16

Offspring produces will have genotypes/phenotypes that are adapted to a stable environment

Question 17

Why is outbreeding more important in terms of evolution?

Answer 17

Different genotypes are required for Natural Selection to occur

Question 18

What is the name of the thick outer wall of a pollen grain?

Answer 18

Exine

Question 19

What is the name of the thin inner wall of a pollen grain?

Answer 19

Intine

Question 20

Describe the formation of a pollen grain:

Answer 20

1) Diploid cells in the pollen sac undergo meiosis to form haploid cells
2) each haploid cell develops into a pollen grain with an exine and intine
3) When the pollen is ripe, the outer layers of the anther dry out
4) the pollen sacs curl away
5) Pollen grain is exposed

Question 21

What is fertilisation?

Answer 21

The process whereby the male gamete fuses with the female gamete to produce a zygote

Question 22

Describe the process of fertilisation in plants:

Answer 22

1) pollen grain lands on stigma
2) Pollen grain absorbs water and germinates
- pollen tube forms
3) Pollen tube secretes pectinase enzymes, digesting style tissues
4) Pollen tube moves down style and enters ovule via the micropyle
5) tip of tube bursts
6) Male gamete nucleus enters embryo sac
7) male nucleus fuses with female nucleus
8) zygote develops

Question 23

What does an Embryonic Plant consist of, and how is it formed?

Answer 23

1) Diploid zygote divides by mitosis - forms embryonic plant
2) Consists of:
a) plumule
b) radicle
c) endosperm
d) cotelydons (1-2)

Question 24

What is the endosperm, and what is it formed from?

Answer 24

1) food reserve for developing embryo
2) formed from embryo sac

Question 25

What is a plumule?

Answer 25

An embryo shoot

Question 26

What is a radicle?

Answer 26

embryo root

Question 27

What is a testa, and what is it formed from?

Answer 27

SEED COAT Formed from INTEGUMENTS

Question 28

What happens to the Micropyle after fertilisation?

Answer 28

nothing - It remains but in the testa

Question 29

What is the seed formed from?

Answer 29

fertilised ovule

Question 30

What is a fruit formed from?

Answer 30

fertilised ovary

Question 31

What are Monocotyledons?

Answer 31

seeds which contain one cotelydon

which forms the first leaf

Cotyledon surrounded by endosperm e.g. cereals

Question 32

What are Dicotyledons?

Answer 32

seeds which contain two cotelydons

cotelydons contain endosperm

e.g. broad bean

Question 33

What are the 3 main requirements for successful germination?

Answer 33

1) temperature - optimum needed for enzymes in germination
2) water - needed for mobilisation of enzymes
- cell transport
- cell vacuolation
3) oxygen - aerobic respiration -> ATP -> metabolism and growth (mitosis)

Question 34

How do broad beans (dicotyledons) germinate?

Answer 34

1) Water absorbed - tissues swell, enzymes mobilise
2) testa ruptured
3) Radicle pushes through testa downwards
4) plumule pushes upwards - Bent over into hook
5) amylase hydrolyses starch to maltose - maltose transported to growing points for respiration
6) plumule emerges, unfurls and begins photosynthesis
7) Cotyledons food reserves are depleted

Question 35

Why is the plumule bent over when it emerges from the testa?

Answer 35

To prevent soil abrasion

Question 36

What occurs to the cotyledons in germination?

Answer 36

1) remain below ground
2) endosperm get depleted within cotyledons