CB11: Mendelian genetics & inheritance patterns

Question 1

What does Mendelian inheritance apply to?

Answer 1

Monogenic traits

Question 2

What is the law of segregation?

Answer 2

Only one of the 2 copies of a gene is given to a gamete randomly.

Question 3

What is the law of independent assortment?

Answer 3

Alleles of 2 or more different genes are segregated independently.

Question 4

What is the law of dominance?

Answer 4

Heterozygous individuals only show the dominant phenotype.

Question 5

What is incomplete dominance?

Answer 5

The dominant allele only partially masks the recessive allele.

Question 6

What is co-dominance?

Answer 6

Both alleles show.

Question 7

What is a monohybrid cross?

Answer 7

A cross involving only 1 gene.

Question 8

What is a dihybrid cross?

Answer 8

A cross involving 2 genes.

Question 9

What is a test cross?

Answer 9

A cross to see if an individual with the dominant phenotype is homozygous or heterozygous.

Question 10

How do you perform a test cross?

Answer 10

You cross the test individual with a recessive parent.

Question 11

If the result of the chi-squared test is lower than the critical value, what does this mean?

Answer 11

That the statistical difference is not significant, so the hypothesis is confirmed.

Question 12

What are monogenic traits?

Answer 12

Traits that involve only 1 gene, so the gene has a strong effect while the environment has a small effect.

Question 13

What are oligogenic traits?

Answer 13

Traits that involve a few genes, where the genes and environment have a relatively similar effect.

Question 14

What are polygenic traits?

Answer 14

Traits that involve many genes, so the environment has a strong effect while the genes have a more minor effect.

Question 15

What is the wild type?

Answer 15

The most common allele in a population.

Question 16

What is loss of function in genetic mutation?

Answer 16

When an allele (usually recessive) produces less products.

Question 17

What is haplosufficiency in loss of function?

Answer 17

When the mutation is from the recessive allele so the phenotype remains.

Question 18

What is haploinsufficiency in loss of function?

Answer 18

When the mutation is from the dominant allele so the phenotype changes.

Question 19

What is gain of function in genetic mutation?

Answer 19

When an allele (usually dominant) produces more products leading to a change in phenotype.

Question 20

What is an isoallele?

Answer 20

A mutation where the product does not change so the phenotype remains.