Chapter 4.7 Sexual Reproduction Increases Variation ✓

Question 1

What are the three things that occur in meiosis that results in variation?

Answer 1

-Crossing over
-Random assortment of chromosomes (independent assortment)
-Fertilisation

Question 2

Define chiasma

Answer 2

The point of contact between two (non-sister) chromatids belonging to a maternal and paternal homologous chromosomes where crossing over may occur

Question 3

Define random segregation

Answer 3

The phenomenon that starts during anaphase 1, when the randomly lined up maternal and paternal homologous chromosomes move to opposite poles of the cell.

Question 4

Define random fertilisation

Answer 4

The union of a male and a female gamete, both haploid, which results in a diploid cell called a zygote; it is random because there is no way of knowing which two gametes, each genetically unique, will form the zygote.

Question 5

Explain why sexual reproduction leads to more variation in a population than asexual reproduction

Answer 5

Sexual reproduction increases variation because it combines DNA from two parents. During meiosis, processes like crossing over and independent assortment shuffles genes, and random fertilisation, adds more variety.
Asexual reproduction produces offspring that are genetically identical to the parent because there is only one parent that creates the offspring so therefore there is no mixing of genetic material.