Lecture 7 Flashcards Preview

Undeleted > Lecture 7 > Flashcards

Flashcards in Lecture 7 Deck (25):
0

What are sex infulenced characters? 3

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

1

What are 3 sex limited characters?

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

2

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

yes

3

Cytoplamic inhertd traits.... Is usually inherited how?

from one parent, usually maternal parent

4

Reciprocal crosses give.... in cytoplamically inherited traits

results

5

What is a characteristic of cytoplasmically inherited traits?

exhibit extensive phenotypic variation, even within a single family

6

What is the genetic maternal effect?

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

7

In cytoplasmic inheritance, who is the genes inherited from?

only from one paretn

8

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

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

9

What is genomic imprinting ?

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

10

What are examples of genomic imprinting?

prader-willi and angelman syndromes

11

What is genomic imprinting due to?

DNA methylation differences in sperm and eggs

12

What are symptoms of Prader-Willi?

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

13

What is the genetic variation with prader-willi?

deletion in long arm of chromsome 15

14

What is the genetic variation for angelman syndrome?

deletion in long arm of chromosome 15

15

What are the symptoms of angelman syndrome?

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

16

What is the methylation of DNA in mammals?

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

17

What are the different levels of methlyation?

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

18

sex linked characteristics

genes located on the sex chromosome

19

sex influenced characteristic

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

20

sex limited characteristic

autosomal genes whose expression is limited to one sex

21

genetic maternal effect

nuclear genotype of the maternal parent

22

cytoplasmic inheritance

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

23

genomic imprinting

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

24

an allele whose product is functional only at certain temps?

temp sensitive allele