Transcript Unit 2 - Glen Rose FFA

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.