Chapter 18: Inheritence

Question 1

What is an allele?

Answer 1

Alternate forms of the same gene found on corresponding gene locus of homologous chromosomes

Question 2

What is the difference between pheontype and genotype?

Answer 2

Pheontype is the expressed trait (physical trait) of an organism, genotype is the genetic make-up of an organism (combination of genes)

Question 3

What does it mean when a trait is homozygous?

Answer 3

The 2 allels that control that trait are identical (PP or pp)

Question 4

What does it mean when a trait is heterozygous?

Answer 4

The 2 alleles that control that trait are different (Pp)

Question 5

What is the difference between complete and incomplete domincance?

Answer 5

Complete: The combination of the dominant and recessive allele expresses the trait of the dominant allele

Incomplete: The combination of the dominant and recessive allele expresses the traits of both alleles leaning more to the dominant phenotype

Question 6

What is codominance?

Answer 6

Both alleles having an equal effect on the phenotype of the offspring

Question 7

What are variations?

Answer 7

Differences in traits between individuals of the same species

Question 8

What is the difference between discontinued and continued variation?

Answer 8

Discontinued variation is brought about by one or a few genes (blood type), while continued variation is brought about by the additive effect of many genes (skin tone)

Question 9

What is a sex-linked gene?

Answer 9

A gene that is located on sex chromosomes

Question 10

Which sex chromosome has more genes found on it?

Answer 10

X-chromosome

Question 11

What are some X-linked disorders?

Answer 11

Red-green colourblindness, Muscular Distrophy