Variation

Question 1

what it means to have more or less variation in a population

Answer 1

More variation means there are many different alleles for traits in a population, making individuals genetically diverse.
Less variation means fewer differences, so individuals are more genetically similar.

Question 2

what the sources of genetic variation are

Answer 2

Genetic variation comes from mutations, independent assortment, crossing over, and random fertilisation.

Question 3

difference between sexual and asexual reproduction

Answer 3

Sexual reproduction involves two parents and produces genetically different offspring.
Asexual reproduction involves one parent and produces genetically identical offspring

Question 4

how sexual reproduction causes genetic variation

Answer 4

Sexual reproduction mixes alleles from two parents, creating new combinations of genes through meiosis and fertilisation.

Question 5

what happens in the cell before meiosis

Answer 5

The cell copies its DNA so each chromosome is made of two identical sister chromatids joined at a centromere.

Question 6

explain the process of crossing over

Answer 6

During meiosis, homologous chromosomes swap sections of DNA, creating new allele combinations on each chromosome.

Question 7

explain the process of independent assortment

Answer 7

Homologous chromosomes line up randomly during meiosis, so each gamete gets a random mix of maternal and paternal chromosomes.

Question 8

can define segregation

Answer 8

Segregation is when allele pairs separate during meiosis, so each gamete gets only one allele for each gene.

Question 9

explain how meiosis affects genetic variation

Answer 9

Meiosis increases genetic variation through crossing over, independent assortment, and segregation.

Question 10

define sister chromatids

Answer 10

Sister chromatids are identical copies of a chromosome, joined together at the centromere after DNA replication.

Question 11

define homologous chromosomes

Answer 11

Homologous chromosomes are pairs of chromosomes (one from each parent) that have the same genes in the same order, but may have different alleles.

Question 12

define meiosis

Answer 12

Meiosis is a type of cell division that produces four genetically different haploid gametes from one diploid cell.