1. Animal Physiology and Understanding Animal Reproduction
Essential Standard 8.00
Understand animal reproduction
Objective 8.02
Understand genetics of animal breeding.

2. Animal Cell
The body is made up of millions of tiny structural units called cells!
The cell is the basic unit of the body that supports and sustains life of an animal.

3. Animal Cell
Nucleus
Cytoplasm
Cell Membrane

4. Cell Parts Protoplasm Cell Membrane Centrosome
The material or contents inside of a cell
Cell Membrane
A thin layer of protein and fat that surround the cell
Some substances can pass into the cell
The membrane blocks other materials from entering
Centrosome
Small body where the microtubules are made
The centrosome divides during mitosis

5. Cell Parts Nucleus Cytoplasm Golgi Body
Gives cell ability to grow, digest good, and divide
Contains chromosomes and DNA
Cytoplasm
A jellylike substance that gives the cell shape and contains components necessary for cell functions
Golgi Body
Located near the nucleus and produces the membrane that surrounds the lysosomes.

6. Cell Parts Lysosome Mitochondrion Nuclear Membrane
Round shaped organelles that contain digestive enzymes that allow for digestion of cell nutrients
Mitochondrion
Rod-shaped organelles that contain digestive enzymes that allow for digestion of cell nutrients
Nuclear Membrane
The membrane that surrounds the nucleus

7. Cell Parts Nucleolus Endoplasmic Reticulum Vacuole Ribosomes
Organelle found inside the nucleus
Produced ribosomal RNA
Endoplasmic Reticulum
Transports materials through the cell
Vacuole
Fluid filled membrane that fills with food and waste products inside the cell
Ribosomes
Site of protein synthesis

10. Cell Division

11. Mitosis
Type of cell division that increases the total number of cells and results in animal growth with the chromosome pairs being duplicated in each new cell
Results in animal growth
Animals begin as a single cell
Chromosomes are duplicated in each new cell as division occurs

12. Mitosis Steps Prophase Metaphase Anaphase Telophase
The nucleolus disappears and centrioles move to opposite end of the cell
Fibers begin to form and extend the centromeres
Metaphase
Spindle fibers align the chromosomes along the middle of the cell nucleus
Anaphase
The paired chrosomes separate and move to opposite sides of the cell
Telophase
Nuclear membrane forms around the newly dividied chromosomes and cell membrane begins to contract

16. Mitosis Video
Mitosis Video

17. Meiosis
Type of cell division that produces the sex cells or gametes that have ½ the number of chromosomes that body cells have

18. Gamete Formation
One set of chromosomes come from the sperm and one from the ovum
The zygote that is created during fertilization has chromosomes from each parent
Chromosomes match up with one another based on the genetic information they carry.

19. Sex Cell Formation
Sex cell formation of the sperm and ova are also produced through meiosis
Production of sperm is called spermatogenesis
Male animals begin producing sperm at sexual maturity
Spermatocytes divide into spermatids through meiosis
Production of ovum is called oogenesis
Females also begin producing ova at sexual maturity
The oocytes divide and form an ovum
The ovum contains cytoplasm and stored food.
It provides nourishment for the zygote and embryo.

21. Meiosis Video
Meiosis Video

23. Chromosomes Rod shaped bodies Made of protein
Found in the cell nucleus
Exist in pairs except for gamete cells
The number of chromosome pairs differ for various animals
Cattle 30
Swine 19
Horses 33
Chickens 39
Humans 23

24. Genes Located on chromosomes Thousands found in each animal
Control inherited characteristics from parents
Carcass traits
Growth rate
Feed efficiency
Two types of inherited traits
Dominant
Recessive

25. Two Types of Genes Dominant Recessive
Hides the effect of recessive genes (covers recessive traits)
Represented by a capital letter
Recessive
Masked by dominant genes (can show up in heterozygous gene pairs)
Pp x Pp combine as homozygous recessive “pp”
In this case, if “p” is the recessive trait for horns, the calf will have horns.

26. Homozygous and Heterozygous
Homozygous gene pair
Carries two genes for a trait
Polled cow might carry the gene PP
Heterozygous
Carries two different genes that affect a trait
Polled cows might carry a recessive gene with the dominant Pp

27. Heritability Estimates

28. Heritability
Estimated the likelihood of a trait being passed on from the parent to the offspring
Heritability estimates vary from 0% to about 70%
If a trait is highly heritable, a producer will see improvements faster than traits that have a low heritability estimate
Heritability estimates for traits in beef cattle are generally higher than for traits in swine.

29. Heritability
Heritability traits are usually higher for carcass quality traits than for reproduction traits in both swine and cattle.
Traits with low heritability estimates are improved most through environment.
Those traits with high heritability estimates are improved most by selective breeding and environmental improvements.

30. Questions?

31. Parts of the Cell Inside the Cell Video
Web Resources
Parts of the Cell Inside the Cell Video