Genetics

Question 1

Gene

Answer 1

Genetic Material (RNA or DNA) coding for a single gene product ( Peptide, rRNA, tRNA)

Question 2

Locus

Answer 2

The chromosomal Location of a gene

Question 3

Allele

Answer 3

One Variant of a gene. Eye color alleles will code for the same trait but one may code for brown and the other may code for blue

Question 4

Homologous Chromosomes

Answer 4

Chromosomes that code for the same set of genes (but may have different alleles) one received from each parent

Question 5

How many chromosomes in humans?

Answer 5

46 chromosomes, 23 pairs. 1 pair related to gender

Question 6

Law of Segregation

Answer 6

Separation of alleles in haploid gametes. Mendel. We are diploid but they separate in your gametes

Question 7

Law of Independent Assortment

Answer 7

Genes assort independently to the progeny. Linkage violates this

Question 8

Complete Dominance

Answer 8

When a Heterozygote has the phenotype of 1 of the alleles (the dominant one)

Question 9

incomplete dominance

Answer 9

phenotypes of progeny are blends of the parental phenotypes. Black person and White person will have Tan kids

Question 10

Codominance

Answer 10

Both inherited alleles are completely expressed. Blood types ABO

Question 11

Pleiotropism

Answer 11

When a gene has multiple phenotypes associated with its expression

Question 12

polygenism

Answer 12

when multiple genes affect a trait. Opposite of Pleiotropism

Question 13

Penetrance

Answer 13

Probability of an organism with a specific genotype will express a specific phenotype.

Question 14

Expressivity

Answer 14

Term describing the variation of a phenotype for a specific genotype. (degree of yellowness, dark-light)

Question 15

Epistasis

Answer 15

Occurs when the expression of a gene us dependent upon another gene. Gene for red hair dependent on gene for male pattern baldness. Can’t have red hair if you’re bald.

Question 16

Which sex is responsible for determining sex of child

Answer 16

father. Can only get an X from mom, Can get either an X or Y from dad.

Question 17

Colorblindness

Answer 17

X-linked recessive. Usually only present in males

Question 18

Mitochondria

Answer 18

Have own DNA/ribosomes. All from Mother

Question 19

Turner’s Syndrome

Answer 19

1 sex chromosome X. Develops as female, results from nondisjunction.

Question 20

Kleinfelter’s syndrome

Answer 20

3 sex chromosomes. XXY. Male. nondisjunction

Question 21

Point Mutations

Answer 21

Substitution, insertion, deletion. Change of single nucleotide.

Question 22

Missense Mutation

Answer 22

Point mutation leading to a codon coding for a different amino acid (substitution). Could be deleterious or not. If you change out one non polar AA for another non polar one it’s ok. If you swap it with a charged AA it could be bad. 3rd base of codon not a big deal.

Question 23

nonsense mutation

Answer 23

point mutation leading to a stop codon

Question 24

frameshift mutation

Answer 24

insertion or deletion leading to a change in the reading frame of a gene. Add one or remove one nucleotide. Causes major changes, almost always deleterious.