lecture 25 - inheritance

Question 1

inheritance

Answer 1

transfer of hereditary traits from one generation to the next

Question 2

alleles

Answer 2

alternative forms of a gene that codes for the same trait and are on the same location on homologous chromosomes

Question 3

mutation

Answer 3

permanent change in an allele that leads to a different version of the same trait

Question 4

genotype

Answer 4

genetic makeup

Question 5

phenotype

Answer 5

phydical expression of a gene

Question 6

punnett square

Answer 6

inheritance of dominant and recessive alleles for normal traits

Question 7

punnett square example

Answer 7

parent 1 = Bb
parent 2 = Bb

B = brown, dominant
b = blue, recessive

outcomes:
BB - brown
Bb - brown
Bb - brown
bb - blue

number of genotypes = 3
number of phenotypes = 2

Question 8

homozygous

Answer 8

two of the same alleles
eg. BB, or bb

Question 9

heterozygous

Answer 9

two different alleles
eg. Bb

Question 10

punnitt square examples of:

heterozygous dominant trait
homozygous dominant trait
homozygous recessive trait

Answer 10

hetero dom - Bb (50%)
homo dom - BB (25%)
homo recessive - bb (25%)

Question 11

heterozygous alleles can show co dominance, waht does this result in

Answer 11

a shared phenotype

Question 12

dominant allele

Answer 12

fully expressed
masks recessive
controls phenotype

Question 13

recessive allele

Answer 13

fully masked by dominant
controls recessive trait

Question 14

abnormaliteis from cells division (2)

Answer 14

nondisjuction
translocation

Question 15

nondisjunction

Answer 15

abnormal number of chromosomes

also called aneuploidy

can be monosomy or trisomy

Question 16

translocation

Answer 16

interchanging of chromosome portions between non homologous chromosomes

Question 17

genetic imprinting

Answer 17

mutated gene or and abnormal trait particularily inhertied form teh mother OR father

Question 18

nondisjuction in meiosis 1 results in

Answer 18

4 cells:

2 are trisomy
2 and monosomy

Question 19

nondisjunction in meiosis 2

Answer 19

4 cells
1 trisomy
1 monosomy
2 normal

Question 20

X and Y protein coding genes numbers

Answer 20

X - 1100. Y 60

X is much larger than Y

Question 21

X chromosome inactivation. what is it and function

Answer 21

transcriptional silencing of one X in females

• equalizes gene dosage
• makes sure there is one functional X in each body cell
• occurs early in development in all cells except in oocytes

other X becomes a barr body