Animal Science Frameworks Presentation Unit 2 Mr. Sullivan

Mendel’s Contributions to the Study of Genetics ► In the mid-1800's, an Austrian monk named Gregor Mendel conducted experimental crosses with pea plants to understand the basic patterns of inheritance. ► Mendel's approach provided the basis for modern genetics.

Mendel's Four Principles of Inheritance ► Genes In Pairs: Genetic characters are controlled by unit factors (genes) that exist in pairs in individual organisms. ► Dominance and Recessive ness: When two unlike unit factors responsible for a single character are present in a single individual, one unit factor is dominant to the other, which is said to be recessive. ► The Principle of Segregation: During the formation of gametes, the paired unit factors separate (segregate) randomly so that each gamete receives one or the other with equal likelihood. ► The Principle of Independent Assortment: During gamete formation, segregating pairs of unit factors assort independently of each other.

The Functions of Cells ► Cells: the cell theory states that a cell is the basic unit of life. ► All organisms are made up of one or more cells.

Cells Must: ► Take up nutrients from the external environment. ► Excrete waste products into the external environment. ► They must work to make the organism survive. ► Reproduce

Functions of Chromosomes ► Chromosomes are small strands of genetic material that reside in the nucleus. ► They are made of a compound that controls inheritance. ► The compound is DNA (Deoxyribonucleic Acid).

Functions of Genes ► Chromosomes contain genes ► Genes are small pieces of DNA ► They tell cells what to do ► The color of your hair and various other physical characteristics are thanks to your genes

Genotype ► The genotype of an animal is its actual genetic code. ► It can NOT be changed by environmental factors.

Phenotype ► The appearance of an animal. ► Some phonotypical traits can be changed with contributors to environment.

Pure Breeding ► Inbreeding: is the mating of closely related animals. ► Linebreeding: is the mating of related animals that are not immediate family members.

Crossbreeding ► Crossbreeding or Outbreeding: is the mating of animals that are not related.

Factors to Consider in Selecting Breeding Animals ► Mate the “Best” with the “Best” ► The most recent and useful data to observe is the Expected Progeny Difference commonly called the EPD.

Expected Progeny Difference (EPD) ► EPDs are records of relatives within and without the herd (even dead ancestors).

Genetic Engineering and its Effect on the Livestock Industry ► Genetic Engineering is a process that begun with the domestication of livestock. ► From the first human decisions made as to what animals should be culled from a herd to the latest efforts in embryo transplanting and cloning (which is done excessively without public knowledge).

Genetic Engineering and its Effect on the Livestock Industry ► The most predominant effect on the livestock industry is the dramatic depletion of the Small Farmer ► Those producers not able to incorporate the latest technological advances in their production fall behind.