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Flashcards in Lecture 7 Deck (25)
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0
Q

What are 3 sex limited characters?

A

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

1
Q

What are sex infulenced characters? 3

A

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

2
Q

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

A

yes

3
Q

Cytoplamic inhertd traits…. Is usually inherited how?

A

from one parent, usually maternal parent

4
Q

Reciprocal crosses give…. in cytoplamically inherited traits

A

results

5
Q

What is a characteristic of cytoplasmically inherited traits?

A

exhibit extensive phenotypic variation, even within a single family

6
Q

What is the genetic maternal effect?

A

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

7
Q

In cytoplasmic inheritance, who is the genes inherited from?

A

only from one paretn

8
Q

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

A

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

9
Q

What is genomic imprinting ?

A

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

10
Q

What are examples of genomic imprinting?

A

prader-willi and angelman syndromes

11
Q

What is genomic imprinting due to?

A

DNA methylation differences in sperm and eggs

12
Q

What are symptoms of Prader-Willi?

A
small hands and feet
short stature
poor sexual development
mental retardation
voracious appetites, usually obese
mutations is always inherited from father
13
Q

What is the genetic variation with prader-willi?

A

deletion in long arm of chromsome 15

14
Q

What is the genetic variation for angelman syndrome?

A

deletion in long arm of chromosome 15

15
Q

What are the symptoms of angelman syndrome?

A
exhibit frequent laughter
uncontrolled muscle movement
large mouth
unusual seizures
mutation is always inherited from mother
16
Q

What is the methylation of DNA in mammals?

A

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

17
Q

What are the different levels of methlyation?

A

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

18
Q

sex linked characteristics

A

genes located on the sex chromosome

19
Q

sex influenced characteristic

A

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

20
Q

sex limited characteristic

A

autosomal genes whose expression is limited to one sex

21
Q

genetic maternal effect

A

nuclear genotype of the maternal parent

22
Q

cytoplasmic inheritance

A

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

23
Q

genomic imprinting

A

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

24
Q

an allele whose product is functional only at certain temps?

A

temp sensitive allele