6.3- Germination

Question 1

What are the two classes of angiosperms

Answer 1

monocotyledons
dicotyledons

Question 2

Describe monocotyldons

Answer 2

herbaceous ( can be woody)
vascular bundles scattered
major veins run parallel in leaves
flower parts in multiples of 2 and 3
embryos have one cotyledon

grasses, palms, orchids, banans

Question 3

Describe dicotyldons

Answer 3

herbaceous or woody

vascular bundles in a ring
netted vascular system in leaves

flower parts in multiples of 4 or 5
embryos have two cotyledons

magnolias
oaks
willows
blueberries

Question 4

Draw a flower structure

Answer 4

Carpel- Stigma, Style
Stamen- Anther, Filament
Petal
Ovary
Ovule
Sepa

Question 5

Anther function

Answer 5

produces pollen containing male nuclei

Question 6

Filament function

Answer 6

stalk holding anther

Question 7

Stigma function

Answer 7

sticky top where pollen lands

Question 8

Style function

Answer 8

supports the stigma

Question 9

Petal function

Answer 9

adaptation to attract pollinators

Question 10

Sepal functiion

Answer 10

protects flower while in bud

Question 11

Ovule function

Answer 11

chamber within ovary where female nuclei is produced

Question 12

Adaptations of insect-pollinated flowers to attract pollinators

Answer 12

large and brightly coloured
strong scents and nectar as a reward

pollen is sticky with spikes to adhere to the insect

stigma is sticky to aid in transfer of pollen

Question 13

What does success in plant reproduction depend on

Answer 13

pollination
fertilisation
seed dispersal

Question 14

Def pollination

Answer 14

transfer of pollen from an anther to a stigma

Question 15

Def fertilisation (plant)

Answer 15

fusion of a male and female gamete to form a zygote

Question 16

Def seed dispersal

Answer 16

carrying seeds away from parent plant to reduce competition

Question 17

PROCESS: Sexual reproduction in flowering plants

Answer 17

1. Pollen adheres to stigma and begins forming the pollen tube
2. Pollen tube penetrates style to take the pollen nuclei towards the ovule. Each pollen tube carries two male nuclei
3. Pollen tube enters ovule through the micropyle to deliver male nuclei to female. 4. Fertilisation occurs, forming a zygote

Question 18

What two types of pollination exist

Answer 18

Self-pollination and Cross-pollination

Question 19

Self- pollination

Answer 19

pollen produced and transferred to the stigma within the same plant
fusion of male and female nuclei occurs forming a zygote
genetic variation reduced
flowers contain both male and female structures

Question 20

Cross-pollination

Answer 20

pollen produced in one plant transferred to another
genetic variation
fusion of male and female gametes to produce a zygote
plants have adaptations to attract animal pollinators
plants have both female and male or either or structures.

Question 21

Self-incompatability mechanisms in plants?

Answer 21

reduces genetic variation, affecting gene transcription and thus growth of plant

pollen tube fails to grow from pollen grain
pollen tube fails to penetrate style
pollen tube enters ovule but pollen nuclei degenerates
pollen tube enters ovule, fertilisation occurs, however zygote degenerates.

Question 22

Cross-pollination in plants….

Answer 22

promotes genetic variation even when flowers are hermaphroditic

Question 23

Def hermaphroditic

Answer 23

both male and female structures

Question 24

Various mechanisms that have evolved to promote cross-pollination

Answer 24

1. Different Maturation times
   - pollen and ovule have different maturation times on the same flower to prevent self-pollination
2. Chemical incompatibility
   - pollen and stigma of the same plant are incompatible, therefore pollen tube cannot grow
3. Separate male/female
   - flowers + plants
4. Wind-pollination
   - pollen is light enough to be carried away on the wind.

Question 25

When do seeds form

Answer 25

after successful fertiisation

Question 26

Why do plants produce fruits

Answer 26

the ovary ripens to produce a fruit, using a lot of chemical energy to attract animals to eat and therefore disperse their seeds via egestion away from parent plant

Question 27

Why is seed dispersal required

Answer 27

to distribute seeds away from the parent plant and reduce competition

Question 28

What is seed dispersal

Answer 28

distribution of mature seeds

Question 29

Methods of seed dispersal

Answer 29

Wind/Water - lightweight feather shaped seeds are able to be carried on the wind/water Animals - via egestion, or hooked/sticky seeds catch onto passing animals and drop off later. Explosions - seed pods explode to propel seeds away from parent plant

Question 30

Why does dormancy occur and when does it occur

Answer 30

after a seed is formed in a flower. dormancy is an adaptation to the environment to avoid unfavourable environmental conditions

Question 31

Three factors required for successful germination

Answer 31

Water - rehydrates dried seed tissue - allows enzyme activity - seed swells and the seed coat bursts allowing the embryo plant to exit the seed Oxygen - allows ATP production via aerobic respiration Warmth - warmer temperatures increases germination until a certain point as reactions that take place are controlled by enzymes which cannot function at low temperatures

Question 32

PROCESS: Seed Germination

Answer 32

1. Water is absorbed (imbibition) which ruptures the seed coat 2. activates the production of gibberellic acid which is a plant growth hormone that acts on food storage cells 3. triggers enzyme activity - amylase acts on stored starch to create maltose - maltase acts on maltose to create flucose - peptidase converts stored proteins to amino acids. 4. stored nutrients translocated in phloem to growing points of stem and root 5. amino acids and glucose used for protein synthesis and respiration which results in growth and development of stem and root. 6. Seedling emerges