Introduction (1)

Question 1

What is reproduction?

Answer 1

Reproduction is the ability of organisms to produce a new generation of themselves. It is extremely important for the survival and evolution of a species because through reproduction, an individual passes on its genes to the next generation.

Question 2

What are the two natural types of reproduction? (2)

Answer 2

• Asexual

- Sexual

Question 3

What is asexual reproduction?

Answer 3

production of a new generation of the same species by one parent.

Question 4

What is sexual reproduction?

Answer 4

production of a new generation of the same species by bringing together the genetic material of two parents.

Question 5

What is the similarity between asexual and sexual reproduction? (2)

Answer 5

While there are large differences between the two processes they do have in common that both processes:
•produce the same kind of organisms in order to prevent their species from dying out and becoming extinct.
•result in food being produced, which is vital to feed the world’s growing population.

Question 6

Number of parents in Asexual reproduction vs Reproduction?

Answer 6

Asexual: One, i.e. all individuals can produce offspring
Sexual: Two, with two genders

Question 7

What is the difference in processes between Asexual reproduction vs Sexual reproduction?

Answer 7

Asexual: One stage, i.e. mitosis with no fusion of cells, therefore is quicker.
Sexual: Two stages, i.e. meiosis and fertilisation with fusion of two cells, therefore is slower

Question 8

Gamete formation in Asexual reproduction vs Sexual reproduction?

Answer 8

Asexual: No gametes formed
Sexual: Gametes formed

Question 9

What is the difference in the end result in Asexual reproduction vs Sexual reproduction?

Answer 9

Asexual: Offspring are genetically identical to the parent, i.e. there is no variation because alleles are not shuffled.
Sexual: Offspring are genetically different to parents, i.e. there is variation because alleles are shuffled during:
• meiosis, when gametes are formed
• fertilisation, when alleles are joined in new combinations

Question 10

What is the difference in value between Asexual reproduction vs Sexual reproduction?

Answer 10

Asexual: In unchanging (stable) environment, well adapted individuals are preserved Reproduction is possible where there are no or few mates
Sexual: In changing (unstable) environment, individuals with variations can adapt to new conditions

Question 11

What is the difference between the rate of reproduction between Asexual reproduction vs Sexual reproduction?

Answer 11

Asexual: Faster – all individuals can reproduce offspring
Sexual: Slowerprocess – half population are males who do not produce offspring

Question 12

What is the difference between the energy input in Asexual reproduction vs Sexual reproduction?

Answer 12

Asexual: More efficient, no energy input needed
Sexual: Less efficient, energy input is needed to produce gametes, and find and court a mate

Question 13

What is the difference between the outside agents in Asexual reproduction vs Sexual reproduction?

Answer 13

Asexual: None needed
Sexual: Pollinators often necessary for pollination

Question 14

Ability to adapt to environment in Asexual reproduction vs Sexual reproduction?

Answer 14

Asexual: No
Sexual: Yes

Question 15

Possibility of evolution in Asexual reproduction vs Sexual reproduction?

Answer 15

Asexual: Low – usually no genotype variation
Sexual: Good- genotype variation

Question 16

What are the advantages of asexual reproduction? (4)

Answer 16

The advantages of asexual reproduction include the following: • All individuals can produce offspring therefore there is no expenditure of energy to produce gametes or find a mate.

• The process is simple and fast as it involves only mitosis, e.g. a single bacterium by dividing into two every 20 minutes can produce 16 million bacteria in 8 hours.
• It is very useful in unchanging (stable) conditions, i.e. if the parent is well adapted to a particular environment the genetically identical offspring will also be well adapted.
• A favourable mutation can spread rapidly enabling the population to adapt quickly to new environmental conditions, e.g. resistance to antibiotics and insecticides.

Question 17

What are the disadvantages of asexual reproduction? (2)

Answer 17

• Unless there is a mutation, there is no variation in the offspring as there is no recombination of alleles. If the environment changes the population might be unable to adapt to the new conditions and could die out.
• Overcrowding may occur and resources such as food might be in short supply.

Question 18

What is the advantage of sexual reproduction? (4)

Answer 18

Sexual reproduction results in variation which:

• is the basis of evolution.
• gives organisms a better chance of survival in an unstable environment as the offspring may be able to adapt to the new conditions.
• may prevent the spread of disease as the offspring might be genetically resistant to a particular disease.
• may reduce the chance of inheriting a disease from a parent.

Question 19

What are the disadvantages of sexual reproduction? (4)

Answer 19

• There is a high expenditure of energy as in plants special organs of reproduction need to be produced, i.e. flowers.
• The reproduction process is slower than asexual reproduction as it takes time for gamete production and the meeting of gametes. •Unfavourable mutations and recessive genes might be expressed in the offspring.
• Outside agents may be needed in plants to carry pollen or seeds.