Genetics

Question 0

Locus def

Answer 0

The chromosomal location of a gene

Question 1

Gene def

Answer 1

Genetic material coding for a single gene product (peptide, rRNA or tRNA)

Question 2

Allele def

Answer 2

One variant of a gene

Question 3

Homologous chromosomes def

Answer 3

Chromosomes that code for the same set of genes

• may have different alleles
• one recieved from each parent

Ex) both chromosomes have hair color on their gene
One may have blonde one may have brown

Question 4

Genotype vs phenotype
B=brown
B=blue

Answer 4

Genotype: BB
Phenotype: brown

Question 5

Law of segregation

Answer 5

Separation of alleles in the haploid gametes

-the two alleles for a gene separate into our gametes

Question 6

Law of independent assortment

Answer 6

Genes assort independently into the progeny

Question 7

Complete dominance

Answer 7

When a heterozygote has the phenotype of only one of the alleles (the dominant one)

Question 8

Incomplete dominance

Answer 8

Phenotypes of the dominance are blends of the parental phenotypes

Question 9

Codominance

Answer 9

Both inherited alleles are completely expressed

Question 10

YyRr x YyRr

Answer 10

Y_R_ 9
Y_rr 3
yyR_ 3
Yyrr 1

Question 11

Test cross

Answer 11

Determines a genotype

-cross with a homozygous recessive

Question 12

Pleiotropism

Answer 12

When a gene has multiple phenotypes associated with its expression

Question 13

Polygenism

Answer 13

Multiple genes affect a single trait

Question 14

Penetrance

Answer 14

Probability an organism with a specific genotype will express a particular phenotype

Question 15

Expressivity

Answer 15

Term describing the variation of phenotype for a specific genotype

Question 16

Epistasis

Answer 16

Occurs when the expression of a gene is dependent upon another gene
-expression of red hair is dependent on whether you have hair

Question 17

Out of the 46 chromosomes, which are linked to our gender

Answer 17

2 x and y chromosomes

All orher 44 chromosomes are called the autosomes

Question 18

If you are a female what are your chromosomes

Male?

Answer 18

Female: xx
Male: xy

Question 19

Who determines the sex of the offspring?

Answer 19

The male

• the female always provides an x
• it is up to the male whether he provides an x or y

Question 20

X or y chromosome larger

Answer 20

X-has many genes

Y-is very small, not many genes

Question 21

Turner syndrome

Answer 21

Child only has an x chromosome

• ends up a female
• from nondisjunction

Question 22

Kleinfelter syndrome

Answer 22

Child has three sex chromosome

• xxy
• develop as a male
• from nomdisjunction

Question 23

Point mutation

Answer 23

Substitution, insertion, deletion

-change of a single nucleotide

Question 24

Missense mutation

Answer 24

Point mutation leading to a codon coding for a different amino acid
-may or may not have a big affect on the protein

Question 25

Point mutation that has no consequence

Answer 25

Point mutation in the third position of the codon

Question 26

Nonsense mutation

Answer 26

Point mutation that leads to a premature stop codon

Question 27

Frame-shift mutations

Answer 27

Insertion or deletion lesding to a change in the reading frame of a gene