INHERITANCE AND VARIATION AQA GCSE

How many parents are needed for asexual reproduction?

• Two parents
• One parent
• Two parents and two grandparents

What is fertilisation?

• When the nuclei of egg and sperm fuse
• When an egg is released from the ovary
• When a new body cell is created

How many chromosomes are present in human gametes?

• 46
• 92
• 23

Why does a dominant allele create a higher probability of an offspring affected by an inherited disease?

• Only one dominant parental allele is needed to produce a 50% chance of an individual being affected by a particular genetic condition
• The parents always pass on these alleles
• Dominant alleles are more common than recessive alleles

What phenotype is produced from an XY genotype?

• Female
• Male
• Cystic fibrosis

Why does cystic fibrosis need two alleles to cause the disease?

• It is a recessive disorder - you need two recessive alleles to cause the condition
• The alleles are dominant and you need two of them
• You need a dominant and a recessive allele to cause the condition

What is an example of a dominant genetic disorder?

• Cystic fibrosis
• Tuberculosis
• Polydactyly

What causes variation?

• Your environment

• Your genes and your environment

• Your genes

• Your names

What is variation?

• Racial diversity

• The variation of females and males

• Variation of personalities

• The differences between the individuals in a species

Where are genes found?

• In the mitochondria

• In our bone marrow

• Chromosomes, in the nucleus of a cell

• In our brains