Animal Science Animal Science Frameworks Frameworks

Presentation Unit 2Presentation Unit 2

Mr. SullivanMr. Sullivan

Mendel’s Contributions to the Mendel’s Contributions to the Study of GeneticsStudy of Genetics

► In the mid-1800's, an Austrian monk In the mid-1800's, an Austrian monk named Gregor Mendel conducted named Gregor Mendel conducted experimental crosses with pea plants experimental crosses with pea plants to understand the basic patterns of to understand the basic patterns of inheritance. inheritance.

►Mendel's approach provided the basis Mendel's approach provided the basis for modern genetics. for modern genetics.

Mendel's Four Principles of Mendel's Four Principles of Inheritance Inheritance

► Genes In PairsGenes In Pairs: Genetic characters are controlled : Genetic characters are controlled by unit factors (genes) that exist in pairs in by unit factors (genes) that exist in pairs in individual organisms. individual organisms.

► Dominance and Recessive nessDominance and Recessive ness: When two unlike : When two unlike unit factors responsible for a single character are unit factors responsible for a single character are present in a single individual, one unit factor is present in a single individual, one unit factor is dominantdominant to the other, which is said to be to the other, which is said to be recessiverecessive. .

► The Principle of SegregationThe Principle of Segregation: During the : During the formation of gametes, the paired unit factors formation of gametes, the paired unit factors separate (segregate) randomly so that each gamete separate (segregate) randomly so that each gamete receives one or the other with equal likelihood. receives one or the other with equal likelihood.

► The Principle of Independent AssortmentThe Principle of Independent Assortment: : During gamete formation, segregating pairs of unit During gamete formation, segregating pairs of unit factors assort independently of each other. factors assort independently of each other.

The Functions of CellsThe Functions of Cells

►Cells: the cell theory states that a cell Cells: the cell theory states that a cell is the basic unit of life.is the basic unit of life.

►All organisms are made up of one or All organisms are made up of one or more cells.more cells.

Cells Must:Cells Must:

►Take up nutrients from the external Take up nutrients from the external environment.environment.

►Excrete waste products into the Excrete waste products into the external environment.external environment.

►They must work to make the organism They must work to make the organism survive.survive.

►ReproduceReproduce

Functions of ChromosomesFunctions of Chromosomes

►Chromosomes are small strands of Chromosomes are small strands of genetic material that reside in the genetic material that reside in the nucleus.nucleus.

►They are made of a compound that They are made of a compound that controls inheritance.controls inheritance.

►The compound is DNA The compound is DNA (Deoxyribonucleic Acid).(Deoxyribonucleic Acid).

Functions of GenesFunctions of Genes

►Chromosomes contain genesChromosomes contain genes►Genes are small pieces of DNAGenes are small pieces of DNA►They tell cells what to doThey tell cells what to do►The color of your hair and various The color of your hair and various

other physical characteristics are other physical characteristics are thanks to your genes thanks to your genes

GenotypeGenotype

►The genotype of an animal is its actual The genotype of an animal is its actual genetic code.genetic code.

► It can NOT be changed by It can NOT be changed by environmental factors.environmental factors.

PhenotypePhenotype

►The appearance of an animal.The appearance of an animal.►Some phonotypical traits can be Some phonotypical traits can be

changed with contributors to changed with contributors to environment.environment.

Pure BreedingPure Breeding

► Inbreeding: is the mating of closely Inbreeding: is the mating of closely related animals.related animals.

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

CrossbreedingCrossbreeding

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

Factors to Consider in Selecting Factors to Consider in Selecting Breeding AnimalsBreeding Animals

►Mate the “Best” with the “Best”Mate the “Best” with the “Best”►The most recent and useful data to The most recent and useful data to

observe is the Expected Progeny observe is the Expected Progeny Difference commonly called the EPD.Difference commonly called the EPD.

Expected Progeny Difference Expected Progeny Difference (EPD)(EPD)

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

Genetic Engineering and its Genetic Engineering and its Effect on the Livestock IndustryEffect on the Livestock Industry

►Genetic Engineering is a process that Genetic Engineering is a process that begun with the domestication of begun with the domestication of livestock.livestock.

►From the first human decisions made From the first human decisions made as to what animals should be culled as to what animals should be culled from a herd to the latest efforts in from a herd to the latest efforts in embryo transplanting and cloning embryo transplanting and cloning (which is done excessively without (which is done excessively without public knowledge).public knowledge).

Genetic Engineering and its Genetic Engineering and its Effect on the Livestock Industry Effect on the Livestock Industry

►The most predominant effect on the The most predominant effect on the livestock industry is the dramatic livestock industry is the dramatic depletion of the Small Farmerdepletion of the Small Farmer

►Those producers not able to Those producers not able to incorporate the latest technological incorporate the latest technological advances in their production fall advances in their production fall behind.behind.