reproduction

Question 1

What is asexual reproduction?

Answer 1

asexual reproduction refers to a parent reproducing an identical offspring without a mate

Question 2

What is sexual reproduction?

Answer 2

sexual reproduction is when both parents are required to produce and offspring.

Question 3

How does a plant reproduce asexually?

Answer 3

Plants reproduce asexually by vegetative reproduction (modification to the stem), this requires specialised plant tissues to grow into a new plant when it becomes separated from the parent plant.

Question 4

list and describe ways a plant can reproduce asexually

Answer 4

• runner: grow horizontally along the ground above giving rise to roots.
  Eg. strawberries
• rhizome: A horizontal underground stem that sends out both shoots and roots. Eg. ginger
• budding: An outgrowth of a new plant form the side of the parent cell
  Eg. prickly pear

Question 5

identify an advantage and disadvantage of asexual reproduction in plants

Answer 5

advantage: Able to reproduce when external pressures are difficult

disadvantage: Less variation which decreases the the ability to adapt

Question 6

In sexual reproduction, plants go through a process of pollination. list the female and male gametes of a plant

Answer 6

female: ovum
male: pollen grains
the stigma is a sticky bulb where it catches the pollen grains. the pollen grains then travel down to the style until it reaches the ovum to fertilise.

Question 7

identify an advantage and disadvantage of sexual reproduction in plants

Answer 7

disadvantage:
- favourbale gene may not be passe s

advantage:
- Ensures survival if reproductive partners are scarce

Question 8

describe how fungi reproduce by budding

Answer 8

1. outgrowth of bud forms on parent cell under favourbale conditions. dna is duplicated and nucleus splits
2. daughter nucleus move into the bud/outgrowth
3. bud pinches inwards at the base of the parent cell and detaches
4. process is repeated, making a chain of independant buds

Question 9

describe the process of binary fission in bacteria

Answer 9

simple version:
1. Cell elongates
2. Genome replicates
3. Duplicated DNA separates
4. Cell wall forms in cleavage furrow
5. Two identical daughter cells are produced

detailed response:
1. cell elongates by building more cell wall

2. bacterial genome replicates and remains attached to the membrane. at the same time, plasmids are replicated
3. duplicated dna begins to seperate, moving towards the poles as the cell elongates more.
4. cleavage furrow begins to form and cell wall begins to form in cleavage furrow.
5. two identical daughter cells are produced

Question 10

What is fertilisation?

Answer 10

fertilisation refers to the fusion of gametes to form a zygote

Question 11

what is external fertilisation?

Answer 11

External fertilisation - when a male sperm fertilises the egg outside of the female’s body, this usually takes place with aquatic animals such as frogs.

Question 12

what is internal fertilisation?

Answer 12

the fusion of gametes that occur inside the female such as humans and whales

Question 13

list advantages and disadvantages of external fertilisation

Answer 13

Advantage:
- Many offsprings are produced
- Less energy and time requirement

disadvantage:
- Not all gametes are fertilised
- Zygotes are more at risk of harm to the environment as they are not protected. (predation and disease)
- Not all offspring surviving

Question 14

list advantages and disadvantages of internal fertilisation

Answer 14

advantage:
- Higher chance of fertilisation because gametes are positioned close together to the female reproductive tract
- Zygotes and gametes are protected from predation and disease
- Increased chance of survival

disadvantage:
- Producing fewer offspring
- More energy intensive for the female
- Risk of sexually transmitted diseases increases.