Reproduction in Plants

Question 1

How does asexual reproduction work?

Answer 1

• Does not involve sex cells or fertilisation
• Only one parent is required

Question 2

Define asexual reproduction

Answer 2

A process resulting in genetically identical offsprings from one parent

Question 3

What happens as a result to offsprings in asexual reproduction?

Answer 3

Genetically identical to the parent and one another

Question 4

Give an example of asexual reproduction

Answer 4

Binary fission of bacteria

Question 5

What are the advantages of asexual reproduction?

Answer 5

• Population can be increased rapidly when conditions are right.
• can exploit suitable environments quickly
• more time and energy efficient
• completed much faster than sexual reproduction

Question 6

What are the disadvantages of asexual repeoduction?

Answer 6

• limited genetic variation in population
• population is vulnerable to changes in condition and may only be suited for one habitat
• disease is likely to affect whole population as there is no genetic variation.

Question 7

Why is asexual reproduction in crop plants adavatagous?

Answer 7

A plant has good characteristics (High yield, disease resistant) can be made to reproduce asexually and the entire crop will show the same characteristics.

Question 8

Define sexual reproduction.

Answer 8

A process involving the fusion of the nuclei of two gametes (sex cells) to form a zygote (fertilised egg cell) and the production of offspring that are genetically different from each other.

Question 9

Define fertilisation.

Answer 9

Fusion of gamete nuclei

Question 10

Define gamete

Answer 10

A sex cell

Question 11

How do gametes differ from normal cells?

Answer 11

Half the no. of chromosomes

Question 12

How many chromosomes are contained in a zygote?

Answer 12

46

Question 13

How many chromosomes does the nuclei of gamete consist?

Answer 13

23 (Haploid)

Question 14

How many chromosomes does the zygote consist of ?

Answer 14

23 pairs (Diploid)

Question 15

What are the adavantages of sexual reproduction?

Answer 15

• increases genetic variation
• the species adapt to new environments due to variation
• disease is less likely to affect population (due to variation).

Question 16

What’s are the disadvantages of sexual reproduction?

Answer 16

• takes time and energy to find mates
• difficult for isolated members of the species to reproduce.

Question 17

What is the advantage for crops that usually reproduce sexually?

Answer 17

Variation increases

Able to survive weather conditions

Question 18

What is the diadvantage for crops that usually reproduce sexually?

Answer 18

May lead to offsprings that are less successful than parent growing.

Question 19

What is the male gamete in a plant?

Answer 19

pollen

Question 20

What is the difference in male gamete from a human and a plant?

Answer 20

The plant one is not capable of locomotion

Question 21

What is the female gamete in a plant?

Answer 21

Stigma

Question 22

What are the 2 ways pollination takes place?

Answer 22

Insect pollinated
Wind pollinated

Question 23

What are the two types of wind pollination?

Answer 23

• Self pollination
• Cross pollination

Question 24

What is the difference in pollen grains repeoduced in insect pollination and wind pollination?

Answer 24

Insects:
- Small amounts
- large
- heavy
- spiky or hv hooks

Wind:
- large amounts
- small
- lightweight
- smooth

Question 25

Define fertilisation in terms of pollination.

Answer 25

Pollen nucleus fuses with an ovum nucleus

Question 26

Briefly name the steps it has to go through to fertilise in a flower.

Answer 26

1. Stigma 2. Style/pollen tube 3. Ovary 4. Ovules

Question 27

What are the factors that affect the germination of seeds?

Answer 27

1. Water 2. Oxygen 3. Warmth

Question 28

How does water affect the germination of seeds?

Answer 28

Allows seed to swell up and the enzymes embryo to start working so that growth can occur

Question 29

How does the oxygen affect the germination of seeds?

Answer 29

so that energy can be released for germination.

Question 30

How does warmth affect the germination of seeds?

Answer 30

Germination improves as temp rises (up to max) as the reactions which take place are controlled by enzyme reactions.

Question 31

Define cross - pollination.

Answer 31

Pollen from one plant is transferred to the stigma of another plant of the same species.

Question 32

Define self pollination.

Answer 32

Pollen from flower lands on it's own stigma or the stigma of another flower on the same plant.

Question 33

How is lack of variation a disadvantage?

Answer 33

Less likely organisms will adapt to suit new conditions.

Question 34

Define germination

Answer 34

It is the start of growth in the seed.

Question 35

Define pollination.

Answer 35

Transfer of the pollen grain to the stigma.