Genetics

Who is the father of genetic?

Gregor Mendel

Alleles:

Different forms of the same gene

Dominant:

The allele represented by a capital letter, and masks the recessive allele

Recessive:

The allele represented by a lowercase letter, gets masked by the dominant allele

Genotype:

An organism’s genetic makeup

Phenotype:

An organism’s physical looks

Heterozygous:

Two DIFFERENT alleles (ex: Hh)

Homozygous:

Having the SAME two alleles (ex: HH)

Name all the dominant disorders and explain them:

• Huntington’s disease: A disease where the nervous system degenerates

• Achondroplasia: A disorder that causes dwarfism and abnormal bone growth

These diseases are represented by a dominant allele

Name all the recessive disorders and explain them:

• Cystic Fibrosis: A disease that causes thick mucus to build up in the lungs

• Albinism: Lack of pigment in the body

• PKU: A disease where an enzyme responsible for breaking down amino acid is missing

What are a male’s sex chromosomes?

XY

What are a female’s sex chromosomes?

XX

The 23rd pair of chromatid are the sex chromosomes. What are the rest called?

Autosomes

Is the sex of the child determined by the male or female?

Male

What are sex linked traits?

Traits passes down by genes on the sex chromosomes.

What are the 2 most common human traits found in the X chromosome and explain them:

• Hemophilia: A blood clotting disorder

• Red-green colorblindness: difficulty telling the difference between red and green

Remember: X^H is normal and X^h is hemophilia because hemophilia is a recessive disorder

What is a pedigree?

A genetic representation of a family tree that shows traits or a disease

REMEMBER:

In an autosomal dominant pedigree there will be an equal amount of females and males that carry the trait/disease

In a recessive pedigree there will be few people with the trait/disease

In a sex-linked pedigree mainly males will be affected

Antigens:

Proteins on the blood cell that show what blood type it is

Antibodies:

Fight against unfamiliar blood types

What blood type is the universal donor and why:

Blood type O because it has no antigens

What blood type is the universal recipient and why?

Blood type AB because it has no antibodies.

What is the scientific way of saying the blood clumped up?

Agglutination

Codominance:

The expression of BOTH traits. So if a black feathered chicken had a baby with a white feathered chicken then the baby would have BOTH white and black feathers.

Incomplete Dominance:

A BLENDING of two opposing alleles. So if a red and white flower were crossed, the offspring is pink.

Polygenic inheritance:

Traits controlled by 2 or more gene pairs. Examples are skin color, eye color and height.

Height is a polygenic type of inheritance because…

It produces a bell shaped curve on a graph/a range of phenotypes