Genetics

• branch of biology that deals with inheritance
• ( what is passed on from one generation to the next )

visible traits, physical features

genetic make up of the person, not visible

• instructions of phenotype in genotype,
• - genetic make up has genetic code of phenotype

- different versions of a gene/same location, express same trait

• - meiosis, genes shuffled by crossing over
• - independent assortment

" same " alleles that code for (express) the same trait

Alleles code for different traits

• represented by the first Capitalized letter of the dominant trait
• - express the trait, whether its in heterozygous/ homozygous

• - is represented by the first non- capitalized letter of the dominant trait
• - will express trait only if it's in a homozygous condition

a method of finding out the inheritance pattern of a trait between two single organisms

• is a cross between F1 offspring (first generation offspring) of two individuals that differ in two traits of particular interest. For example: RRyy/rrYY or RRYY/rryy parents result in F1 offspring that are heterozygous for both R and Y (RrYy).
• - A dihybrid cross is often used to test for dominant and recessive genes in two separate characteristics.

2 alleles and neither one is dominant over another

whether an organism is homozygous or heterozygous for a certain condition

phenomenon where the effects of one gene are modified by one or several other genes

• is a term which describes the tendency of certain loci or alleles
• to be inherited together. Genetic loci on the same chromosome are
• physically close to one another and tend to stay together during meiosis

relative positions of genes on a chromosome

rate of cross over, how far apart genes are, independant assortment is not going to shuffle genes

usually the inheritance of genes on the x chromosome

size of the chromosomes, X is bigger and Y is smaller

• Sex-linked
• traits are a special case. They are controlled by genes on the sex
• chromosomes, X and Y. The female has two X chromosomes and the male has
• one X and one Y. Both males and females are equally likely to have a
• recessive allele on one X chromosome. However, if a female has a
• recessive allele, there's a good chance that the OTHER X chromosome will
• have a dominant allele, nullifying the effect of the recessive allele
• on the first X chromosome. But, a male does not have another X
• chromosome. So, if he has the recessive allele on his one X chromosome,
• he will have the trait. Period.

cells with an active maternal X chromosome and cells with an active paternal X chromosome

A Barr body is the inactive X chromosome in a female somatic cell, or the inactive Z in a male, rendered inactive in a process called lyonization,

more than 2 alleles code for the same trait

Antigens: substance or molecule that when introduced into the body triggers the production of an antibody by the immune system which will then kill or neutralize the antigen that is recognized as a foreign and potentially harmful invader

Antibody:proteins, are used by the immune system to identify and neutralize foreign objects, such as bacteria and viruses

Because it does not contain any "A" or "B" proteins. "O"- Negative would not contain the rhesus "Rh" factor either, further making it the universal donor.

O negative is the universal donor because there are absolutely no proteins on the RBCs, which means that anyone can receive that blood without suffering rejection. That is the same reason that people with O negative can only receive O negative.

• both alleles are visible in the phenotype
• - both individually expressed

type of inheritance in which one allele for a specific trait is not completely dominant over the other allele. This results in a combined phenotype (expressed physical trait).

recieves any blood type becasue they have both A and B antigens

the antibodies in your plasma will recognize the transfused (donor) blood as foreign and will attack and destroy the donor red blood cells, the RBC will clump together (aggutination) which causes kidney failure and liver failure and even death

"Rhesus monkey " an antigen that can be present on the surface of the RBC

cause: The 1st pregnancy is fine, the placenta hides RBC of fetus from immune system so mother doesnt produce Rh antibodies, but at delivery the placenta tears and there is mixing of the 2 blood and mother gets exposed to Rh and antibodies produce but by that time baby is already delivered, but the 2nd pregnancy, the Rh antibodies will cuase agglutination(clump and stick together) b/c it was explosed to in first pregnancy

Treatment: give mother RhoGam -> anti Rh gamma globulin(protein) it is against Rh label

one pair of alleles causes many changes in phenotype(expressions)

• -caused by a dominant allele
• - causes the collegen fibres to be too elastic
• - many symptoms, joints elastic(easy to dislocate), skin elastic, cant change shape of lens so cant see far

• when you have many pairs of allels/genes
• - wide range of particular phenotypes

• -temperature drops in nose, ears, toes, so alleles get expressed (darker features)
• - the hairs stays dark but base of hair is white
• - allele -> pigment (melanin) "expressed" only if temperature drops lower than 37 degrees

• study of family to figure out genotype of person
• -if dominant, a child that has the trait must have at least one parent also have the trait