Intro to Animal Science genetics and reproduction

Exam Two

Diploid Cells

contain two complete sets of chromosomes, one set inherited from each parent.

haploid cells

(sperm and egg cells), which have only 23 chromosomes (one set).

Trisomy

Chromosomal abnormality

Genome

Complete DNA sequence of an organism

Karyotype

Visual arrangement of chromosomes

Qualitative Trait

Not Influenced by Environment, These traits fall into clear, non-overlapping categories (what you can visually see)

Heritability

Mendel’s Law of Independent Assortment

that alleles for different genes sort independently

Linkage

when genes are located close together on the same chromosome. Since they are close together, they tend to be inherited together, not independently.

Epistasis

when the expression of one gene depends on the other

sex-linked trait

Gene on X or Y chromosome

sex-limited trait

expressed only in one sex due to specific genetic instructions or hormones unique to that sex

two copies of a lethal dominant allele?

They are non-viable

Deleterious recessive traits

expressed only when the allele is homozygous

Semi-lethal traits

reduce viability or performance but are not always fatal.

Punnett square

Predict offspring ratios

Mutations

permanent changes in the DNA sequence

Point mutations

Affect a single nucleotide. These include substitutions, insertions, and deletions.

Frameshift mutations

Insert or delete nucleotides, shifting the reading frame of the gene.

Chromosomal mutations

Involve large changes in chromosome structure or number

Mutations in somatic cells

are not passed down to offspring

mutations in germline cells

are inherited

Proofreading enzymes

proteins that help fix mistakes during DNA replication

economically important trait in livestock

Reproduction

Reproductive Efficiency

Offspring per breeding female

testes

Produce sperm (spermatogenesis) and testosterone

Scrotum

House Testes and Regulate temperature

Vas deferens

Transports sperm to the urethra 

Accessory glands

adds nutrients and buffers to semen

what does the sperm head contain

DNA, and Acrosome

Acrosome

enzyme needed to penetrate egg during fertilization

what does the mid-piece of sperm contain

contains mitoconria for energy 

Estrogen

Regulates menstrual cycle and promotes female secondary sexual characteristics

Progesterone

Prepares uterus for pregnancy and supports gestation

where does fetilizatin take place

oviducts

uterus function in reproduction

implantation and nurishment 

cervix

a barrier between uterus and vagina

What is the role of GnRH in the estrous cycle

Triggers FSH and LH release

what is the function of FSH

stimulates follicle growth

function of LH (Luteinizing Hormone)

induces ovulation, and mantains corpus luteum

corpus luteum

froms the ruptured follicle after ovulation, produces progesterone, thickens the uterine lining 

Progesterone

Maintains pregnancy

what is the function of Prostaglandin F₂α (PGF₂a)

lipid compound that helps restart the estrous cycle by dissolving the corpus luteum

primary goal of artificial insemination

Maximize superior genetics

estrous synchronization

Make females come into heat together

What does a breeding soundness exam (BSE) evaluate in males

Ability to breed successfully

segment of the poultry oviduct is the site of fertilization

Infundibulum

Magnum

Adds albumin (egg white)

Isthmus

Adds shell membranes

Uterus (Shell gland)

Forms the shell

Vagina (chicken)

Passes the egg to the cloaca

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