Stutts - ANSC 4395 Animal Breeding &
Genetics - Test 2 Exam Q’s and A’s
Gregor Mendel - -Father of Genetics
mid 19th century
performed breeding experiment with peas
-Gene - -Basic unit of inheritance
Segments of DNA
Short segments of chromosomes
-Chromosomes - -Long strands of DNA and associated proteins present in
the nucleus of every cell
Present in pairs
-Homologs - -Pair of chromosomes having corresponding loci
-Locus - -The specific location of a gene on a chromosome
-Allele - -an alternative form of a gene
-Dominance of alleles - -how one allele reacts to another allele
-Multiple alleles - -more than two possible alleles at a locus
A a a' a''
-Genotype - -The combination of genes at a particular locus
-Homozygous - -a one-locus genotype containing functionally identical
genes ex:BB, bb
-Heterozygous - -a one-locus genotype containing functionally different
genes ex: Gg, Bb
-Law of Segregation - -Mendel's 1st law
In the formation of a germ cell or gamete, the two genes at a locus in the
parent cell are separated, only one gene being incorporated into each germ
cell.
-Meiosis
-Entire homologous chromosomes seperated
-Germ Cells - -contain half the number of chromosomes and half the
number of genes as normal body cells
, -Law of Independent Assortment - -Mendel's 2nd law
Genes assort independently during meiosis if all possible gametes are
formed in equal proportions
-Linkage - -The occurrence of two or more loci of interest on the same
chromosomes
-Crossing over - -a reciprocal exchange of chromosome segments between
homologs
prior to the time chromosomes are separated to form gametes
-Recombination - -the formation of a new combination of genes on a
chromosome as a result of crossing over
-Gamete Selection - -the process that determines which egg matures and
which sperm succeeds in fertilizing the egg
-Punnett Square - -commonly used device for determining the possible
zygotes obtainable from the mating of any two parental genotypes
-GG - -homozygous dominant
-Gg - -heterozygous (dominant)
-gg - -homozygous recessive
-Mendelian Sampling - -The random sampling of parental genes caused by
segregation and independent assortment of genes during germ cell
formation and by random selection of gametes in the formation of the
embryo
-Dominance - -An interaction between genes at a single locus such that in
heterozygous one allele has more effect
-Simple Inherited Traits - -explains why we got various phenotypes in
specific proportions when we make specific matings
-polygenic inheritance - -chief source of hybrid vigor and inbreeding
depression
-Complete Dominance - -A form of dominance in which the expression of
the heterozygote is identical to the expression of the homozygous dominant
gene type
-Ex: polled train in cattle, color in Angus cattle
-P= polled, PP=polled, Pp=polled, pp=horned
Genetics - Test 2 Exam Q’s and A’s
Gregor Mendel - -Father of Genetics
mid 19th century
performed breeding experiment with peas
-Gene - -Basic unit of inheritance
Segments of DNA
Short segments of chromosomes
-Chromosomes - -Long strands of DNA and associated proteins present in
the nucleus of every cell
Present in pairs
-Homologs - -Pair of chromosomes having corresponding loci
-Locus - -The specific location of a gene on a chromosome
-Allele - -an alternative form of a gene
-Dominance of alleles - -how one allele reacts to another allele
-Multiple alleles - -more than two possible alleles at a locus
A a a' a''
-Genotype - -The combination of genes at a particular locus
-Homozygous - -a one-locus genotype containing functionally identical
genes ex:BB, bb
-Heterozygous - -a one-locus genotype containing functionally different
genes ex: Gg, Bb
-Law of Segregation - -Mendel's 1st law
In the formation of a germ cell or gamete, the two genes at a locus in the
parent cell are separated, only one gene being incorporated into each germ
cell.
-Meiosis
-Entire homologous chromosomes seperated
-Germ Cells - -contain half the number of chromosomes and half the
number of genes as normal body cells
, -Law of Independent Assortment - -Mendel's 2nd law
Genes assort independently during meiosis if all possible gametes are
formed in equal proportions
-Linkage - -The occurrence of two or more loci of interest on the same
chromosomes
-Crossing over - -a reciprocal exchange of chromosome segments between
homologs
prior to the time chromosomes are separated to form gametes
-Recombination - -the formation of a new combination of genes on a
chromosome as a result of crossing over
-Gamete Selection - -the process that determines which egg matures and
which sperm succeeds in fertilizing the egg
-Punnett Square - -commonly used device for determining the possible
zygotes obtainable from the mating of any two parental genotypes
-GG - -homozygous dominant
-Gg - -heterozygous (dominant)
-gg - -homozygous recessive
-Mendelian Sampling - -The random sampling of parental genes caused by
segregation and independent assortment of genes during germ cell
formation and by random selection of gametes in the formation of the
embryo
-Dominance - -An interaction between genes at a single locus such that in
heterozygous one allele has more effect
-Simple Inherited Traits - -explains why we got various phenotypes in
specific proportions when we make specific matings
-polygenic inheritance - -chief source of hybrid vigor and inbreeding
depression
-Complete Dominance - -A form of dominance in which the expression of
the heterozygote is identical to the expression of the homozygous dominant
gene type
-Ex: polled train in cattle, color in Angus cattle
-P= polled, PP=polled, Pp=polled, pp=horned
