B12 Genetics

Question 1

If an organism has two identical alleles for a trait, it is ______ for that trait.

Answer 1

Homozygous

Question 2

Which part of the cell is affected by cystic fibrosis?

Answer 2

The cell membrane

Question 3

What organs does cystic fibrosis affect and how?

Answer 3

Thick, sticky mucus builds up in the air passages and in the pancreas.

Question 4

List 2 types of embryonic screening:

Answer 4

• Pre-implantation genetic diagnosis (PGD)
• Chorionic villus sampling (CVS)

Question 5

How does PGD work?

Answer 5

Cells are removed from embryos during IVF for gene analysis, to decide which ones should be used for implantation.

Question 6

How does CVS work?

Answer 6

A sample of cells are extracted from the placenta at between 10-13 weeks of pregnancy for gene analysis. If the embryo is found to have a genetic disorder, the pregnancy can be terminated

Question 7

List 2 arguments in favour of genetic screening:

Answer 7

• Reduces healthcare costs by reducing population with genetic illnesses
• Stops people from having disorders that lead to low quality of life

Question 8

List 3 arguments against genetic screening:

Answer 8

• Expensive
• Could increase prejudice towards genetic disorders by insinuating that they are undesirable
• People could select embryos based on desirable traits

Question 9

Define allele

Answer 9

Version of a gene

Question 10

Define genotype

Answer 10

Combination of alleles