Bio - 16.3

Question 1

female reproductive parts of the plant

Answer 1

*carpel
1. stigma
2. style
3. ovary
4. ovule

Question 2

male reproductive parts of the plant

Answer 2

*stamen
1. anther
2. filament

Question 3

sepal

Answer 3

• leaf-like structure that form a ring outside the petal of a flower
• to protect the flower while it is a bud
• normally green

Question 4

petals

Answer 4

• coloured structures that attract insects / birds to a flower
• some petals have guide-lines (there is a gland called NECTARY to attract insects who like sugary liquid called nectar)

Question 5

stamens - features (2)

Answer 5

1. anther => structure at the top of the stamen, pollen grains are made inside
2. filament => “stalk” part of stamen, supports anther

*pollen grains => small structures which contain the male gametes of a flower

Question 6

carpel - features (4)

Answer 6

1. stigma => part of flower that receives pollen
2. style => connects stigma to ovary
3. ovary => contains ovule
4. ovule => contains female gametes

Question 7

insects pollinated - features

Answer 7

1. large petals, often with guide-lines
2. strongly scented
3. nectarines at the base of petal
4. anther inside flower
5. stigma inside flower
6. sticky / spiky pollen grains (stick to insects)
7. large quantities of pollen made (either eaten / delivered to wrong plant)

Question 8

wind pollinated - features

Answer 8

1. small / no petals at all
2. no scent
3. no nectaries
4. anthers dangle outside the flower
5. stigmas large, feathery and dangle outside of flower
6. smooth, light pollen
7. large quantities of pollen made (blown away / lost)

Question 9

pollination - definition

Answer 9

transfer of pollen grains from the male part of the plant (stamen) to the female plant (stigma)

Question 10

self pollination - definition

Answer 10

transfer of pollen grains from the anther of a flower to the stigma of the same flower or a diff flower on the same plant

Question 11

cross pollination - definition

Answer 11

transfer of pollen grains from the anther of the flower to the stigma of a flower on a different plant of the same species

Question 12

self pollination - features

Answer 12

• no external agency
• anther and stigma mature at same time
• occurs when flower is closed
• produces homozygous offspring (identical)
• no variations

Question 13

cross pollination - features

Answer 13

• external agent always required
• anther and stigma mature at different time
• occurs when flower is open
• produces heterozygous offspring
• introduces variations

Question 14

steps for fertilisation

Answer 14

1. pollen lands on stigma
2. digestive enzymes eat through the ovary
3. pollen tube grows down to meet ovule for fertilisation
4. female gamete fuses with male gamete
5. forms zygote
6. seed is formed from cell division
7. ovary becomes a fruit

Question 15

3 factors for germination

Answer 15

1. warm temp
2. oxygen
3. water

Question 16

warm temp - germination

Answer 16

• increase growth rate
• enzymic activity

Question 17

oxygen - germination

Answer 17

• needed for aerobic respiration

Question 18

water - germination

Answer 18

• lets the seed swell
• embryo starts to grow
• softens seed coat (testa)
• activate enzymes

Question 19

process of germination

Answer 19

seed absorbs water (micropyle) => testa burst slightly => enzymes activated (amylase + protease) => respiration increased => embryo enlarges => testa bursts open => radicle / root emerges as an anchor (absorbs water and minerals) => followed by shoot / plumule => temp, oxygen and moisture at optimum level

Question 20

germination - enzymes

Answer 20

1. starch
2. protein

Question 21

germination enzymes - starch

Answer 21

starch –(amylase)–> maltose –(maltase)–> glucose

Question 22

germination enzymes - protein

Answer 22

protein –(protease)–> amino acids

Question 23

capacity to respond to changes in the environment - self pollination

Answer 23

low variation => population is less likely to adapt if the environment changes (disease, drought)

Question 24

capacity to respond to changes in the environment - cross pollination

Answer 24

high variation => population is more likely to survive environmental changes due to genetic differences

Question 25

reliance of pollinators - self pollination

Answer 25

doesn't rely heavily on pollinators - can still reproduce if insects / wind are scarce *useful in isolated areas

Question 26

reliance on pollinators - cross pollination

Answer 26

depends on pollinators (insects, wind, water) to transfer pollen between species. without them, reproduction can fail