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ANSC exam 3 (last part before final) > Genetics > Flashcards

Flashcards in Genetics Deck (40):
1

what are genetics

1. transfer of genetic info from one generation to the next
2. allow for existence and adaptation of a species or population

2

define genotype

individuals genetic makeup

3

define pheotype

1. expression of an animals genotype
2. genetics + environment

4

with regards to animal breeding, how do genetics come into play

evaluation of the genetic value of domestic livestock

5

what are the 3 types of genetics with food animal production

1. population genetics
2. quantitative genetics
3. molecular genomics

6

what is population genetics

1. study of allele frequency distribution and change due to natural selection, genetic drift, mutations, and gene low
2. attempts to explain adaptation

7

what is quantitative genetics

1. study of inheritance of continuously measured traits (height and weight) and their mechanisms
2. development of EBV in sheep, EPD in pigs and beef, and PTA in dairy

8

what does EBV, EPD, and PTA stand for and what are they based off of

1. Expected breeding value
2. Expected Progeny Difference
3. Predicted Transmitted Ability

based off of
1. parents performance
2. individual performance
3. progeny performance

9

What is genomics

study of genetics which applies to DNA, DNA sequencing, bioinformatics, and analyze function and structure of genomes

10

what is the central dogma theory

1. developed by Watson and Crick in 1953
2. Genetic material (genotype) is deoxyribonucleic acid which transfers sequential information to make a protein
3. no reverse flow from protein to RNA or DNA

11

What are the 2 steps in protein synthesis

1. Transcription
2. Translation

12

What is transcription

1. first step in protein synthesis
2. DNA to RNA
3. occurs in nucleus

13

what is translation

1. RNA to protein
2. occurs in cytoplasm

14

What is DNA a sequence of

nucleotides

15

what is the sugar in DNA

deoxyribose

16

There are nitrogenous bases in DNA,
1. what are the 2 base groups
2. what are the 2 parts for each group

1. Purines: Adenine & Guanine
2. Pyrmidines Thymine & cytosine

17

what does SNP stand for

single nucleotide polymorphism
(phosphate group)

18

What is the RNA function

to copy DNA code

19

what are the 3 steps in the RNA copying process

1. Transfer (tRNA): matches the genetic code in a 3 nucleotide sequences called anitcodon

2. Messenger (mRNA): encodes for tRNA and moves RNA to cytoplasm

3. Ribosomal (rRNA): structural component of ribosomes (site of protein synthesis

20

what are codons

the genetic code

21

mitosis

process which separates chromosomes into 2 identical daughter cells

22

meiosis

special type of cell division necessary for production of gamates

23

homozygous

similar pari of alleles

24

heterozygous

2 different alleles

25

what is gene expression

info from a gene is used in the synthesis of a functional gene product

26

what is an allele

one of a number of alternative forms of the same gene or gene locus

27

define locus

group of genes

28

what is a dominate allele

member of gene pair in which it masks the phenotype expression of the other allele
*designated by a capital letter

29

recessive allele

member of an allele pair which is only expressed when the dominant allele is absent

30

dominant vs recessive examples in cattle and horses

1. cattle
-black vs red coat
- white face vs colored face
2. horse
-black vs brown

31

what is co-dominance

situation where neither gene is dominant so each trait is expressed in the offspring
example is roan

32

what is incomplete dominance

no dominance exists and heterozygous offspring appear intermediate
ex:
RR=red
rr=white
Rr=pink

33

What is Epistatis

genes at different loci interact with one another

expression of genes at one loci is influenced upon presence of alleles at one or more loci

34

example of epistasis

horse coat color
*gene alleles present at E locus and A locus determine color

35

Explain the E locus

Mainly for body color
*E(dominant) = eumelanin expressed (black)
*e(recessive)= eumelanin is restricted which means phaeomelanin is expressed (red)

36

Explain A locus

A(dominant)= restricts eumelanin to horse points which are the mane, tail, and legs

a(recessive)= do not restrict the eumelanin

37

Explain multiple alleles

*phenotype expression is controlled by many gene locations for example the blood type in humans is controlled by 3 allels

38

explain sex linked inheritance

1. X-linked genes
*passed via non-homologous portion of the x chromosomes
*passed to male (XY) or female (XX)
EX is calico cats
2. Y-Linked
*via non homologous portion of Y chromosomes
*passed only to male

39

Explain sex related inheritance

same gene is expressed differently depending on sex of animal
*horns in sheep
-males genes for horns are dominant over polled
-female gene for polled is dominant over horns

40

explain sex limited traits

genes carried by both sexes, but only expressed by one sex
-female milk production, litter size, egg production
-male: libido, chryptorchid