21st Century - Biology,(B1)

Order from largest -----> Smallest

Cell --> Nucleus --> Chromosome --> Gene

Gene's are codes for make a certain protein.

Proteins
Structural proteins are one's that are in skin, hair, bones,
For example: Collagen found in tendons, bones.

Functional proteins are one's that are used to help the function of organs.
For example: Amylase helps to break down starch during digestion.

Description of genes:

Genotype: All of the genes an organism has.
(Bb, bB, BB, bb)

Phenotype: The characteristics that an orgaism displays.
(with ______, without ______)

Chromosomes:

Two Chromosomes are NEVER identical,
---> They have different allels.

23 pairs of chromosomes, 46 individual chromosomes.

Homozygous: Two alleles the same.

Heterozygous: Two alles that are different.

Genetic disorders:

Cystic Fibrosis (Recessive)
(Ff, fF) = Carrier
(ff) = Sufferer

Huntingdon's disease (Dominant)
(Hh, hH, HH) = Sufferer

Disorders are inherited through faulty genes.

Symptoms

Cystic Fibrosis
- Breathing difficulty
- Chest infections
- Difficulty in digesting food
- Thick sticky mucus

Huntingdon's disease
- Tremors
- Clumsiness
- Memory loss
- Mood changes
- Poor concentration

23rd pair = Sex chromosome pair

** = Female                 XY = Male

Lack of the Y allele causes female characteristics

Y produces a protein that triggers the development of the testes.

Genetic testing (Embryo's)

IVF embryo's can be tested for certain genetic disorders.
When tested, only healthy one are emplanted - Others are destroyed

Who can be tested?

Adults
They can be tested to see if their chilren will inherit a disorder.
Children
They can be tested to see if they have inherited the disorder.
Both
They can be tested for the genetic disorder before drugs are prescribed to them.

Inaccurate - Contaminated/Misinterpreted results
Unsafe - Miscarriages increase chance from 0.5-1% of cases, due to tesing on the amniotic fluid around the fetus.
Unfair - If proven positive, should other members of the family be tested? Should they be allowed to have children?
Termination - Parents unable to cope with a child with a disorder. Reasons: The child has a right to life, Abortion is always wrong.
Discrimination - Employers may not employ someone with a disorder. Employers may take extra care of those with a disorder.
Isolation - Insurance companies may refuse giving life insurance to those with a disorder