Test 5- Genetics Review

Question 1

Gene

Answer 1

unit of biological inheritance (DNA that codes for a particular protein)

Question 2

Allele

Answer 2

one of two or more genes at the same loci on homologous chromosomes (Brown eyes Vs Blue eyes- same gene but different allele)

Question 3

Locus

Answer 3

location on a chromosome

Question 4

Homozygous

Answer 4

both alleles are the same (BB or bb)

Question 5

Heterozygous

Answer 5

the alleles are different (Bb)

Question 6

Dominance

Answer 6

allele which is always expressed (B? = BB or Bb)

Question 7

Recessive

Answer 7

allele which is expressed only if the individual is homozygous for it (bb)

Question 8

Genotype

Answer 8

the total generic makeup (what your genes are- BB = (not) Bb)

Question 9

Phenotype

Answer 9

the set of expressed traits (what you look like- BB = Bb)

Question 10

Principle of Segregation

Answer 10

genes do not blend (DNA strands don’t mix)

Question 11

Principle of Independent Assortment

Answer 11

genes that are not on the same chromosome are not inherited together

Question 12

Probability

Answer 12

Punnet Squares

Question 13

P generation

Answer 13

the original organisms (homozygous = RR or rr)

Question 14

F1 generation

Answer 14

the first offspring (heterozygous = Rr)

Question 15

F2 generation

Answer 15

the second generation result of (F1 x F1)- the interesting one

Question 16

Dihybrid cross

Answer 16

cross involving two different genes (example: RrTt x RrTt)

Question 17

Incomplete Dominance

Answer 17

multiple alleles interfere with each other’s expression generating an “in-between” effect. (RR= Red; WW = White; RW = Pink)

Question 18

Co-dominance

Answer 18

when multiple alleles are both expressed, but do not interfere with each other. (blood types AB = AB not A or B or even mixed AB (p. 344)

Question 19

Polygenic Traits

Answer 19

Traits that are controlled by more than one gene (skin color in humans)

Question 20

Sex-linked traits

Answer 20

variations from standard Dominance Recessive are derived from the fact that makes lack the second set of genes females possess on their second X chromosome

Question 21

Mitochondrial Inheritance

Answer 21

Inheritance seems to pass only from mother to offspring.

Question 22

Pedigree Chart

Answer 22

a graphic organizer that assists scientists in discovering the nature of a particular genetic characteristic- if the parents are the same as each other but different from the child then whatever the child has is recessive

Question 23

TTFFGGHH

Answer 23

1/4 x 2/4 x 0 x 1/4

Question 24

Ttffgghh

Answer 24

2/4 x 0 x 1/2 x 1/4

Question 25

T_F_G_H_

Answer 25

3/4 x 4/4 x 1/2 x 3/4 = 9/32

Question 26

ttFfggHH

Answer 26

1/4 x 2/4 x 1/2 x 1/4 = 2/64