chapter 2 - cell division

Question 1

What are the advantages and disadvantages of asexual reproduction

Answer 1

ADVANTAGES:
faster (quicker population growth)
more energy-efficient
produces identical offspring
does not require the combining of sex cells from two parents

DISADVANTAGES:
low genetic diversity
compounding genetic mutations
increased resource competition

Question 2

What are the advantages and disadvantages of sexual reproduction

Answer 2

ADVANTAGES:
increased genetic variation in offspring

DISADVANTAGES:
much slower than asexual reproduction
requires a lot of energy
it requires time and energy to find a mate and reproduce
- because its so slow if there’s a dramatic population decrease it will take longer to spring back

Question 3

How does independent assortment lead to variation in sexual reproduction

Answer 3

independent assortment is the random orientation of the maternal and paternal homologous chromosomes during metaphase 1 in meiosis, where pairs of homologous chromosomes line up along the metaphase plate INDEPENDENTLY of the other homologous pairs. This leads to a random assortment of paternal and maternal chromosomes in the four haploid daughter cells at the end of meiosis

Question 4

How does crossing over lead to variation in sexual reproduction

Answer 4

During prophase 1 in meiosis, synapsis occurs which is the process of genes located on the same locus swapping over at chiasma which allows DNA from the maternal chromosome to swap with DNA from the paternal chromosome. This means at the end of meiosis, the chromosomes in the four gametes are a recombination of maternal and paternal genes - making each of the gametes genetically varied from each other.

Question 5

How does random fertilisation lead to variation in sexual reproduction

Answer 5

Random fertilisation promotes variation because there is a random fusion of gametes, bringing together chromosomes of alleles in the offspring. The offspring produced in sexual reproduction are genetically different from one another and from their parents resulting in genetic variation within the population because it involves the mixing of genetic information