Genetics, Reproduction, Breeding - ANIMAL SCI 101 UMASS AMHERST

Animal Science 101 UMASS Amherst STUDY

Genetics

The study of heredity

Heredity

The passing of traits from parent to offspring

How traits passed from parent to offspring

Cell → Tissue → Organ → Organ System → Animal

Nucleus' contains what tissue?:

Epithelial

Connective

Muscle

Neural

Nucleus contains what organ system?:

Integumentary

Skeletal

Nervous

Muscular

Cardiovascular

Lympathic/Immune

Respiratory

Digestive

Urinary

Endocrine

Reproductive

Phenotype

The physical appearance/characteristics of an individual

Chromosomes

Coiled mass of DNA and protein that carry genetic information

Autosomes (Human Chromosomes)

Chromosome pairs numbered 1 to 22, excluding the sex chromosomes. The 23rd pair of chromosomes are known as the "Sex Chromosomes"

Genetic Female: XX

Genetic Male: XY

Karyotype

A visual representation of the chromosomes of a species

Bird chromosomes

Sex chromosomes denoted as 'Z' or 'W'

Females determine the sex. sperm always carry a Z chromosome, while eggs may carry a Z (carries sex-linked genes) or a W (smaller chromosome).

Homologous chromosomes

Chromosomes that occur in pairs and carry the same genes

Locus

The specific location of a gene on a chromosome

Alleles

Different forms of a gene that affect the same trait

Homozygous (AA)

An individual with matching alleles at a locus

Heterozygous (Aa)

An individual with different alleles at a locus

Multiple Alleles

Genes with more than or equal to (≥) three alleles

One animal (alleles)

Only 2 alleles exist at each locus.

Population (alleles)

A group of individuals of the same species with many different alleles

Gene Expression

The process by which a gene is used to create a functional protein

Dominant allele

An allele that is expressed to the exclusion of the other
Capital letter, ex: BB

Recessive allele

An allele that is only expressed when the dominant allele is absent

Lowercase, ex: bb

Gene

A segment of DNA on a chromosome that codes for a protein

Nucleotide

A building block of DNA, consisting of a sugar, phosphate, and nitrogen base

DNA

A double helix structure made up of two strands of nucleotides

Transcription

The process of copying a gene into messenger RNA (mRNA)

Translation

The process of reading mRNA to produce a protein

Ploidy

The number of copies of each chromosome in a cell

Diploid

2 copies of each chromosome in body cells (somatic cells)

Haploid

Having one copy of each chromosome in germ cells

Principles of Inheritance

Each parent produces reproductive cells called gametes.  

In the formation of gametes, the parental alleles separate so that each gamete contains only half of the genetic code the parent possesses. 

Inheritance

The method by which alleles are passed from one generation to the next

Gametes

Reproductive cells that contain half of the genetic code of the parent

Mitosis

replication of dying cells and replacement of them through a process of division. result in each daughter cell being exactly the same as the parent cell (full, diploid set of chromosomes)

Meiosis

Type of cell division that creates egg and sperm cells, is genetically unique from the parent, and contains only half the number of chromosomes (DNA)

Meiosis

Cell division in gametes, resulting in half the number of chromosomes

Spermatogenesis

The production of sperm in the testes

Oogenesis

The production of eggs in the ovaries

Gene Effect

The influence of genes on the expression of a trait

Dominance

The relationship between alleles where one is expressed over the other

Codominance

The relationship between alleles where both are expressed in the phenotype

Incomplete dominance

The relationship between alleles where the heterozygote appears as an intermediate between the two alleles

Epistasis

The interaction of multiple gene pairs to influence gene expression

Male Reproductive System function

Produce hormones

Produce spermatozoa

Deliver spermatozoa to the female at the appropriate time

Reproduction

The process of producing offspring

Hypothalamus

The part of the brain that regulates reproductive ability through hormone secretion

GnRH

Gonadotropin-releasing hormone secreted by the hypothalamus

Pituitary Gland

The gland that secretes hormones to regulate reproductive ability

LH

Luteinizing hormone secreted by the anterior pituitary gland

FSH

Follicle-stimulating hormone secreted by the anterior pituitary gland

Testes

The male reproductive organs that produce sperm and hormones

Scrotum

The sac of skin that houses the testes

Cryptorchid

An undescended or retained testicle

Spermatic Cords

Tubular structures that extend from the inguinal ring to the testes

Penis

The male breeding organ

Testicular Descent

The process of the testes moving from inside the abdomen to the scrotum

Epididymis

The storage and maturation site for sperm

Ductus deferens

The duct that carries sperm from the epididymis to the urethra

Urethra

The tube that carries urine and semen out of the body

Accessory Sex Glands

Glands that contribute secretions to semen

Female Reproductive System

The structure and function of the female reproductive system

Ovaries

The female reproductive organs that produce eggs and hormones

Oviducts

Tubes that transport eggs from the ovaries to the uterus

Uterus

The hollow muscular organ where the embryo implants and develops

Cervix

The smooth muscle sphincter between the uterus and vagina

Vagina

The muscular tube that connects the cervix to the vulva

Vulva

The external female genitalia

Oogenesis

The production of eggs in the ovaries

Hypothalamic-Pituitary-Gonadal Axis

The hormonal regulation of the reproductive cycle

Ovulation

The release of a mature egg from the ovary

Corpus Luteum

The structure that forms from the collapsed follicle after ovulation

Estrous Cycle

The reproductive cycle of female mammals

Proestrus

The stage of the estrous cycle where follicles begin developing

Estrus

The stage of the estrous cycle where the female is sexually receptive

Metestrus

The stage of the estrous cycle after ovulation

Diestrus

The stage of the estrous cycle where the corpus luteum is at its maximum size

Anestrus

The stage of the estrous cycle where there is temporary ovarian inactivity

Breeding

Using genetics to improve a species or breed

Gene

Segment of DNA that codes for a unique protein

Nucleotide

Sugar + phosphate + nitrogen base

Mutation

Chemical change in a gene that alters DNA

Allele

Different forms of a gene

Myostatin gene

Gene responsible for muscle growth and fat deposition

Inheritance

Passing of traits from parents to offspring

Simple trait

Trait determined by a single gene

Polygenic trait

Trait determined by multiple genes

Sex-linked inheritance

Genes located on the sex chromosomes

Inbreeding

Mating of closely related individuals

Linebreeding

Inbreeding to concentrate genes of an ancestor

Outbreeding

Mating less closely related individuals

Crossbreeding

Mating animals from different breeds

Genome

Complete set of genes and associated DNA

Genomics

Study of gene function and relationships

Genome map

Known order of genes on a chromosome

Genome mapping

Locating and identifying genes on chromosomes

Marker-assisted selection

Using DNA markers to select individuals with desired traits

Genomic testing

Testing for specific DNA markers

Heritability

Measure of genetic influence on a trait

Breeding value

Value of an animal as a parent

EPD

Expected Progeny Difference

Sire summary

Summary of genetic values for bulls