Genetics Problems SB2C: Using Mendel’s Laws, explain the role of meiosis in reproductive variability.

Select the term that best describes… Both alleles are the same: heterozygous or homozygous Bb: heterozygous or homozygous BB : heterozygous or homozygous Both alleles are different : heterozygous or homozygous bB : heterozygous or homozygous bb : heterozygous or homozygous

Select the term that best describes… bb: genotype or phenotype BB : genotype or phenotype Bb : genotype or phenotype Black hair : genotype or phenotype Physical characteristics : genotype or phenotype Actual genes (alleles) : genotype or phenotype

A green pea plant (Gg) is crossed with a yellow pea plant (gg).

A tall plant (TT) is crossed with a tall plant (Tt).

A tall plant (Tt) is crossed with a short plant (tt).

A red flower (Rr) is crossed with a white flower (rr).

A white flower (rr) is crossed with a white flower (rr).

A black chicken (BB) is crossed with a black chicken (BB).

Codominance: fighting for control Both alleles want to be dominant so BOTH phenotypes will appear. BB black BW black and white WW white A black goat (BB) with a white goat (WW).

Incomplete dominance: a mixture No allele is fully dominant so there is a mixture or blend in the phenotypes. RR red flowers RW pink flowers WW white flowers A red flower (RR) with a white flower (WW)

Sex Linked Traits Genes are located on the sex chromosomes. Colorblindness: 1 in 12 males, 1 in 200 females. WHY? XX normal female *Cross a Normal Male with a XX c carrier female carrier female. X c X c colorblind female XY normal male X c Y colorblind male

What are blood types? There are 3 alleles or genes for blood type: A, B, & O. Since we have 2 genes, there are 6 possible combinations. Blood Types AA or AO = Type A BB or BO = Type B OO = Type O AB = Type AB

How common is your blood type? 46.1% 38.8% 11.1% 3.9%

Blood Transfusions A blood transfusion is a procedure in which blood is given to a patient through an intravenous (IV) line in one of the blood vessels. Blood transfusions are done to replace blood lost during surgery or a serious injury. A transfusion also may be done if a person’s body can't make blood properly because of an illness. Who can give you blood? People with TYPE O blood are called Universal Donors, because they can give blood to any blood type. People with TYPE AB blood are called Universal Recipients, because they can receive any blood type. Rh +  Can receive + or - Rh -  Can only receive - Universal Donor Universal Recipient

Rh Factors Scientists sometimes study Rhesus monkeys to learn more about the human anatomy because there are certain similarities between the two species. While studying Rhesus monkeys, a certain blood protein was discovered. This protein is also present in the blood of some people. Other people, however, do not have the protein. The presence of the protein, or lack of it, is referred to as the Rh (for Rhesus) factor. If your blood does contain the protein, your blood is said to be Rh positive (Rh+). If your blood does not contain the protein, your blood is said to be Rh negative (Rh-). A+ A- B+ B- AB+ AB- O+ O-

Blood Type Problems: i A, i B, i AB, i 1) Both the father and mother have type O blood. 2) The father is type A homozygous, the mother is type B homozygous. 3) The father is type A heterozygous, the mother is type B heterozygous. 4) The father has type O blood, the mother has type AB blood.

Dihybrid Cross: Two traits Let’s Play: er.com/punnett- square-calculator er.com/punnett- square-calculator

Additional Practice A homozygous dominant brown mouse is crossed with a heterozygous brown mouse (tan is the recessive color). Two heterozygous white rabbits are crossed (brown is the recessive color). Two heterozygous red flowers are crossed (white flowers are recessive). A heterozygous white rabbit it crossed with a homozygous black rabbit.