Genetic Diversity, Mutation and Meiosis

Question 1

What occurs in early interphase in meiosis

Answer 1

DNA replicates

Question 2

What are homologous pairs

Answer 2

Chromosomes with the same genes and gene loci but different alleles

Question 3

Gametes

Answer 3

Haploid sex cells

Question 4

Haploid

Answer 4

Cell with a single set of unpaired chromosomes (one of each homologous pair)

Question 5

Diploid

Answer 5

A cell with complete sets of chromosomes (both homologous pairs)

Question 6

Fertilisation

Answer 6

Fusion of 2 haploid gametes

Question 7

What two things cause genetic variation is meiosis

Answer 7

Crossing over and independent assortment

Question 8

Summarise meiosis

Answer 8

Prophase I - Chromosomes condense and visible
Nuclear membrane break down
Metaphase I - Homologous pairs match up on middle and spindles form and attach
Anaphase I - Spindles contract and chromosomes move to opposite poles
Telophase I - Nuclei reform and cell divides
Prophase II - Nuclei break down
Metaphase II - Chromosomes line up on middle, spindle forms and attach to centromere
Anaphase II - Chromatids separated
Telophase II - Nuclei reform and cell divides

Question 9

Gene mutation

Answer 9

Change to base sequence of DNA during DNA replication

Question 10

Chromosome non-disjunction

Answer 10

When chromosomes do not separate during Meiosis I or Meiosis II causing more chromosomes in one cell