ANIMAL BREEEDING AND GENETICS LECTURE ANSCI

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quantitative traits

discrete in phenotypic expression, one or two genes determine the genotypic ratio and does not change despite different environment

qualitative traits

continuous in phenotypic expression, can have two or more traits to determine genotypic expression, may change based on the environment

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animal breeding

involves selective mating of domestic animals to improve desirable traits of the next generation

genetic

the study of heredity, the way where traits from the parents are passed down to their offspring

gregor johann mendel

the father of genetic who studied the garden pea

wilhelm johannes

the one who coined the term gene

gene

it is the basic and functional unit of heredity, its is also a segment of dna located in the chromosome

locus

this is where the genes stays and located in the chromosomes

genotype

genetic composition of organism that determines its phenotypesgen

phenotype

the observable trait of organisms

additive gene action

when many genes acts to determine the phenotype

non-additive gene action

this gene action takes control on the observable trait which only uses one or two traits to determine the phenotype

dominant gene

this is the gene that masks the expression of its allele

recessive trait

this is the one that is being masked on by the other allele

codominance

situation where heterozygous shows the phenotypic effect of both trait equally

incomplete or partial dominance

mixture of two traits

overdominance

gene action that results from the interaction of genes that are alleles and the result surpassed the average trait of the parent

epistasis

when one gene modify the other gene. its the interaction of pair that is not allele

gametogenesis

the process where gametogenesis and oogenesis occur

spermatogenesis 

spermatozoon is produced during this process

oogenesis

oocytes are produced in this process

mitosis

produces two genetically identical daughter cell from parent cell

meiosis

process of division of two chromosomes

diploid

produced or happened during mitosis

haploid

the gametes are halved

spermatogonia 

the baby cell that yet to become sperms, this is diploid cell that happen on mitosis

primary spermatocytes

undergoes meiosis 1 and produces haploids

secondary spermatocytes

undergoes meiosis 2 and creates spermatids

spermatids

immature sperm that waits to be matured. this undergoes spermatogenesis to transform it into sperm

GnRH, FSH, LH

hormones that stimulates spermatogenesis

mother cells

the cells formed during fetal development

fetal development

what stage does oogonia undergoes mitosis

primary oocyte

when oogonia enters meiotic division

diplotene stage or prophase 1

this is where the primary oocyte stays until it reached puberty

secondary oocyte

released during ovulation and can be fertilized

second meiotic division

happens when fertilization occurs and it completes secondary meiosis, forming mature ovum and another polar body

fertilization

refers to the process that results in the formation of zygote

zygote

fusion of two haploids  to form diploid

mendelism

the theory of heredity as formulated by gregor mendel

seed color, seed, shape, pod color, pod shape, flower color, stem height, flower position

7 traits of peas that mendel studied

law of segregation

this law states that every individual organisms contains two alleles for each trait and these alleles segregates during meiosis such that each gamete only contains only one of the alleles  

law of dominance

there are recessive and dominant alleles in this law. it states that if its a pair of dominant and recessive trait, it will follow the dominant trait

law of independent assortment

allele of different genes separate independently during gamete formation

test cross

mendel came up wityh this way on how he can distinguish an organism with dominant phenotypes if its homozygote or heterozygote