Unit 4 Part 4 - Plants

Question 1

Where are gametes of flowering plants produced?

Answer 1

Females - structures called ovules
Males - structures called pollen grains

Question 2

What does meiosis do in plants?

Answer 2

Gives rise to the ovules and pollen grains

Question 3

What does mitosis do in plants?

Answer 3

produce the actual gametes

Question 4

Why is reduction division not required to produce haploid gametes?

Answer 4

B/c reproductive structures are already haploid

Question 5

Hermaphroditic?

Answer 5

Flowers with male and female structures

Question 6

Self pollination?

Answer 6

A form of sexual reproduction b/c gametes are produced by meiosis and there is a fusion of gamete nuclei to form an embryo

Question 7

Disadvantage if self reproduction?

Answer 7

Loss of genetic variation

Question 8

Cross pollination?

Answer 8

Transfer of pollen produced on one plant w/ another plant

Question 9

How do flowers with petals attract pollinators?

Answer 9

They use shapes, markings, and clours

Question 10

Where does pollen develop?

Answer 10

Develops w/in structures called anthers

Question 11

Stigma?

Answer 11

A sticky structure that’s held upright and pollen grains can easily adhere to when pollinators move onto a dif flower

Question 12

Pollen tube?

Answer 12

Pollen that adheres to a stigma

Question 13

Fertilization in plants?

Answer 13

Pollen tube: carries 2 male nuclei
Ovule: 3 haploid nuclei

One pollen nuclues fertilizes one ovule nuclues to create zygote, other pollen nuclues fertilizes other two nuclei to create endosperm

Question 14

Endosperm chromosome

Answer 14

Has 3 b/c three nuclei were used in order to make it

Question 15

Growth of endosperm

Answer 15

Growth of this triploid tissue produces nutritive endosperm w/in seed that will nourish early plant embryo

Question 16

Common insect pollinators?

Answer 16

Bees, wasps, flies, butterflies, and moths

Question 17

Where are stamens of insect pollinating flowers located?

Answer 17

Usually deep inside the flower so that insects drinking nectar will brush up against the pollen grains

Question 18

Flower parts?

Answer 18

• Sepal
• Petal
• Anther
• Pollen
• Filament
• Stigma
• Style
• Ovary
• Ovary

Question 19

Sepal function?

Answer 19

Protecting developing flower while its inside the bud

Question 20

Petal function?

Answer 20

Usually colourful to attract pollinators

Question 21

Another function?

Answer 21

The part of stamen ( male portion of flower) that produces male sec cells (pollen)

Question 22

Pollen function?

Answer 22

Contains male nuclei used for fertilization

Question 23

Filament function?

Answer 23

The stalk of the stamen that holds up the anther

Question 24

Stigma function?

Answer 24

Sticky part of a carpel ( female portion of flower) which pollen lands on

Question 25

Style function?

Answer 25

Part of the carpel that supports stigma

Question 26

Ovary function?

Answer 26

Base of carpel, containing one or more ovules

Question 27

Ovule function?

Answer 27

Chamber w/in an ovary where the female nuclei develop

Question 28

Mechanisms evolved to promote cross - pollination?

Answer 28

• Different maturation times for pollen and ovules
• Chemical self-incompatibility mechanisms are used
• Some flowering plants produce flowers with only either male or female parts
• Some species can only produce their own gender ( must have one sex features)
• Wind

Question 29

Self incompatibility mechanism?

Answer 29

When pollen of a plant lands on stigma of flower of same plant, protein interactions occur that reduce or stop growth of pollen tube

Question 30

Specifics of self - incompatibility mechanism?

Answer 30

• Pollen grain on stigma fails to germinate into a pollen tube
• Pollen grain germinates but doesn’t enter through stigma into style
• Pollen tube enters ovule but pollen nuclei degenerate before fertilisation can occur
• Fertilization occurs but plant embryo degenerates during early growth

Question 31

Conditions needed for a seed to germinate?

Answer 31

Water
- To re hydrate the dried seed tissue
Oxygen
- To allow aerobic respiration to release adenosine triphosphate
Appropriate temp

Question 32

Radical?

Answer 32

The initial root structure that emerges first

Question 33

What structure appears first in a plant?

Answer 33

The hypocytal