Exam 1 Flashcards
Animal Breeding
Discipline in animal science that utilizes the principles of genetics and statistics with the goal of improvement of animals.
Animal Breeding
Science that helps in the quest to breed better animals.
What is a long strand of DNA in the nucleus of a cell
Chromosomes
What is a specific place on a chromosome occupied by a gene
Locus
The basic unit of inheritance
Gene
An alternative form of a gene
Allele
A genetic composition of an individual
Genotype
Physical expression of a genotype
Phenotype
An individual possessing two different alleles at a locus
Homozygote
BB
Homozygote dominant
Bb
Heterozygote
bb
Homozygote recessive
Segregation occurs when gametes are formed at meiosis and each gamete gets only one of the pair of genes at a locus
Segregation and recombination
Recombination occurs when the gametes, which are discrete units, recombine at fertilization
Independent assortment
Factors appear in pairs and a random member of the pair is passed from parent to progeny
Law of Segregation
One factor is capable of masking the presence of the second factor in the expression of a phenotype
A dominant gene
A factor being masked is called what?
Recessive
A strain in which animals of like phenotypes perpetuate those phenotypes in their progeny
Pure breeding strain
What generation is always heterozygous
F-1
Pure breed strains are
homozygus
A progeny resulting from the mating of different pure breeding strains
Hybrid
Mating F-1 animals back to an animal of one or the other of the pure breeding strains used to create the F-1 animals
Backcross
Among themselves
Inter se
A cross involving one parent showing the dominant phenotype and one parent completely recessive
Test cross
What describes inheritance fo multiple traits?
Law of independent assortment
Following the inheritance of more than one trait at a time
Combinations of traits
Chromosomes appear in
Pairs
Organisms having 2n chromosomes
Diploid
Organisms having n chromosomes are referred to as
Haploid
Gametes are the reproductive cells, often called what?
Sex cells
The male gamete is
Sperm
The female gamete is an
egg
Gametes are what
Haploid
What is the random deduction from diploid to haploid?
The formation the gametes
What is the random union of gametes?
The formation of zygote
What is the mathematical likelihood that a particular event will occur?
Probability
P = # of observations of the event/# of total observations
Definition of probability
Probability that one event occurs is not influenced by the occurrence of a second event
Independent events
Probability of two or more events occurring together - -Can be recognized by the word “AND”
Joint probability
AND = joint probability = x multiply
Hybrid’s are
Heterozygous
Dyhybrid’s are
Heterozygous for two different traits
From mating dyhibrids, what is the probability of a progeny with black coat color and spotting
Joint Probability Example
The occurrence of one event preludes the occurrence of a second event. Also, represented by the word OR.
Mutually exclusive events
Probability of an event A given a second event has occurred.
Conditional probabilities
more crossovers mean
that two loci are far apart
Formation of gametes is a ____ reduction from diploid to haploid
random
df=
number of categories -1
if X^2 >cv
rejected
if X^2 <cv
fail to reject
