Download Genetics Primer

Genetics Primer
Who is Gregor Mendel?
O The father of “modern genetics”
O First studied inheritance patterns using garden
pea plants
O He observed that traits were inherited as
separate units.
O His work formed the foundation for the era of
modern genetics, the study of the function and
behavior of genes.
Genes
O The basic units of heredity.
O Every living organism carries a set of genes inside its
cells.
O Biochemical information that is transmitted from
generation to generation by DNA (deoxyribonucleic
acid).
O Our genes are the genetically unique blueprint that
makes us who we are.
O The color of a flower, your pet’s coat pattern, the ability to
have musical talent
O Only identical twins have genes that are exactly the same!
Who are geneticists?
O Scientists who study genes and their variations.
O Their goal is to: understand how information is
encoded in genes and how it is transmitted
from one generation to the next.
O They also study how disease may be caused and
how to manipulate genes (genetic engineering)
Why is Genetics Important?
Current issues
O Cloning
O Treating disease with stem cell and gene therapy
O Conducting genetic testing for human disease
O Understanding products with risk-vs.-benefit
controversies ( UV rays, radiation, food additives,
agricultural chemicals)
Currently,
O Scientists are creating genetic maps, a process to chart
position of known genes and other markers relative to
each other.
O Now using genetic engineering techniques they are
mapping the genomes of many species.
O Genome- the whole hereditary information of an organism
that is encoded in the DNA or an organism
O Why: understand disease, appropriate treatment plans,
design of medication
Mendel’s Rules: A Pattern of
Inheritance
O Genotype: combination of genes that code for a trait
O Phenotype: describes the physical manifestation of
that trait
O 1.
that the inheritance of each trait is determined
by genes that are passed on to descendants
unchanged
O 2.
that an individual inherits one such unit from
each parent for each trait
O 3.
that a trait may not show up in an individual but
can still be passed on to the next generation.
Exceptions to Mendel’s Rule
1.
Incomplete dominance: the inheritance of a dominant and
recessive trait results in a blending
2.
Quantitative inheritance: Multiple genes control the trait ( ex.
Skin color)
3.
Multiple genes: Certain traits are controlled by multiple genes
that have complex rules of dominance
4.
Gene linkage: When certain genes occur close together on the
same chromosome, they can act as one prior to dividing in
development
5.
Sex-linked traits: Because the sex chromosomes differ from a
male and female different traits may be carried ( Hemophilia,
color blindness)