Lecture 7

Question 0

What are 3 sex limited characters?

Answer 0

determined by autosomal genes
expressed in only one sex
have zero penetrance in opposite sex

Question 1

What are sex infulenced characters? 3

Answer 1

determined by autosomal genes
inherited according to mendelian prinicples
expressed differently in males and females

Question 2

What are four characteristics of cytoplamically inherited traits? is it present in males and females?

Answer 2

yes

Question 3

Cytoplamic inhertd traits…. Is usually inherited how?

Answer 3

from one parent, usually maternal parent

Question 4

Reciprocal crosses give…. in cytoplamically inherited traits

Answer 4

results

Question 5

What is a characteristic of cytoplasmically inherited traits?

Answer 5

exhibit extensive phenotypic variation, even within a single family

Question 6

What is the genetic maternal effect?

Answer 6

phenotype of the offspring is determined by the genotype of the mother

Question 7

In cytoplasmic inheritance, who is the genes inherited from?

Answer 7

only from one paretn

Question 8

Who are the genes inherited from in the genetic maternal effect?

Answer 8

are inherited from both parents but the offspring’s phenotype is determined by the mother’s genotype, not its own

Question 9

What is genomic imprinting ?

Answer 9

Differential expression depending on whether it is inherited from the male or the female parent.

Question 10

What are examples of genomic imprinting?

Answer 10

prader-willi and angelman syndromes

Question 11

What is genomic imprinting due to?

Answer 11

DNA methylation differences in sperm and eggs

Question 12

What are symptoms of Prader-Willi?

Answer 12

small hands and feet
short stature
poor sexual development
mental retardation
voracious appetites, usually obese
mutations is always inherited from father

Question 13

What is the genetic variation with prader-willi?

Answer 13

deletion in long arm of chromsome 15

Question 14

What is the genetic variation for angelman syndrome?

Answer 14

deletion in long arm of chromosome 15

Question 15

What are the symptoms of angelman syndrome?

Answer 15

exhibit frequent laughter
uncontrolled muscle movement
large mouth
unusual seizures
mutation is always inherited from mother

Question 16

What is the methylation of DNA in mammals?

Answer 16

Methylation is erased in germ cells of each generation and then reestablished in the course of gamete formation

Question 17

What are the different levels of methlyation?

Answer 17

sperm and eggs undergo different levels of methylation, resulting in the differentail expression of male and female alleles in the offspring

Question 18

sex linked characteristics

Answer 18

genes located on the sex chromosome

Question 19

sex influenced characteristic

Answer 19

genes on autosomal chromosomes that are more readily expressed in one sex

Question 20

sex limited characteristic

Answer 20

autosomal genes whose expression is limited to one sex

Question 21

genetic maternal effect

Answer 21

nuclear genotype of the maternal parent

Question 22

cytoplasmic inheritance

Answer 22

cytoplamic genes, which are usually inherited entirely from only one parent

Question 23

genomic imprinting

Answer 23

genes whose expression is affected by the sex of the transmitting parent

Question 24

an allele whose product is functional only at certain temps?

Answer 24

temp sensitive allele