plants reproduction 3.3, 3.4, 3.5, 3.6, 3.7

Question 1

what are the three natural methods of asexual reproduction in plants?

Answer 1

runners
tubers
bulbs

Question 2

what’s the artificial method of asexual reproduction in plants?

Answer 2

cuttings

Question 3

explain the runners method of asexual reproduction:

Answer 3

a new plant is produced when a runner touches the ground

Question 4

explain the tubers method of asexual reproduction:

Answer 4

swollen underground stems containing lots of stored food
one plant can produce many tubers, which can grow man shoots to form new plants

Question 5

explain the bulbs method of asexual reproduction:

Answer 5

underground buds with thick fleshy leaves contain stored food
the main shoot will grow out of the parent bulb and another will grow out of the daughter bulb forming two plants

Question 6

explain the cuttings method of asexual reproduction:

Answer 6

a piece of a plant stem with a few leaves attached is cut from a healthy plant
planted in damp compost, where it will grow roots and develop into a new plant

Question 7

whats the sex organs of a plant?

Answer 7

flowers

Question 8

whats the three main functions of flowers as sex organs?

Answer 8

• productuion of gametes
• sites of pollination and fertilizaation
• sites of seed and fruit formation

Question 9

what are the two gametes of flowers?

Answer 9

pollen - gamete produced in anther (male)
ova - gamete produced in the ovary (female)

Question 10

explain the structure and process of the gamete pollen:

Answer 10

pollen is the gamete produced in the anther which is part of the male part (stamen) of a flower
- anther
- pollen grains
- pollen sacks
- filament

Question 11

explain the structure and process of the gamete ova:

Answer 11

ova is the gamete produced in the ovules found in the ovary within the female part of the flower
- carpel
- ovule
- ovary
- ova

Question 12

what’s the name of the pollination from one plant to another?

Answer 12

cross pollination

Question 13

what’s the name of the pollination that involved only one plant?

Answer 13

self pollination

Question 14

what’s the structure of a flower?

Answer 14

carpel:
- stigma
- style
- ovary
- ovule
stamen:
- anther
- filament

Question 15

what’s the process of fertilization in plants?

Answer 15

1. pollen grains are deposited into a stigma
2. pollen grain normally grows a pollen tube which grows down the style
3. enzymes are secreted at the tip of the tube which digests the tissues of style
4. when the tube reaches an ovule the male gamete travels through the tube entering a small hole called the micropyle
5. fuses with the female gamete in the process of fertilization
6. the fertilised ovum divides via osmosis to form the embryo
7. the ovule develops a seed
8. the ovary developed into the fruit

Question 16

what happens once fertilization has taken place in plants?

Answer 16

fertilised ovule becomes a seed then an ovary then a fruit

1. zygote develops into an embryonic plant with a small root (radicle) and shoot (plumule)
2. the other contents of the ovule developed into cotyledons, which will be a food store for the young plant when it germinates
3. the ovule wall becomes the seed coat or testa (the hard coating of the seed)
4. ovary wall becomes fruit coat

Question 17

germination:

Answer 17

germinating seeds need a lot of energy so they use their food stores using enzymes and break down the carbohydrate stores
uss fuels in respiration to release energy
this occurs until leaves are in a position to photosynthesise

Question 18

what do plants need to germinate?

Answer 18

oxygen - to aerobically respire
warmth - optimum temperature for enzymes
water - to activate enzymes

Question 19

practical
investigating the conditions needed for germination:

Answer 19

cress seeds are added to cotton wool in test tubes
- tube A put in the fridge and rest on the windowsill
- tube C has moist, boiling water added to the cotton wool and an oxygen absorber so that there is no oxygen
- tube E is wrapped in tin foil
- tube B has no water
- tube D has all conditions needed for germination
check for germination 2-3 days later
combine classes results and calculate % germination

Question 20

how does sexual reproduction occur in plants?

Answer 20

three steps:
- pollination
- fertllisation
- germination

Question 21

what are the features of a flower stamen in both an insect and wind-pollinating plant?

Answer 21

insect - enclosed within the flower
wind - exposed outside petals

Question 22

what are the features of a flower stigma in both an insect and wind-pollinating plant?

Answer 22

insect - enclosed within flower and sticky
wind - exposed outside of petals and often feathery

Question 23

what are the features of flower petals in both an insect and wind-pollinating plant?

Answer 23

insect - large and brightly coloured
wind - small and usually green

Question 24

what are the features of flower nectaries in both an insect and wind-pollinating plant?

Answer 24

insect - present = produce sugary fluid to attract insects
wind - absent

Question 25

why do insect-pollinated flowers have structural adaptions?

Answer 25

to attract insects to them and ensure the insects push close to the stamen and the stigma within the flower

Question 26

why do wind-pollinating flowers have structural adaptions?

Answer 26

need to expose their stamens and stigma to the wind