Genetics

My Grandpa and Grandma both have blood type AB and my dad has blood type A. My Mom has blood type AB. Dad and mom have me! What is the probability I can have blood type B?

• 0%

• 25%

• 50%

• 100%

Albinism is a recessive sex linked trait on the X allele in aliens. If an albino alien is born to two parents who are purple, what conclusion may be drawn about the genotypes of the parent aliens?

• Both parents must be homozygous for the coloration gene.

• Both parents must be heterozygous for the coloration gene.

• The female parent must have two recessive alleles for the coloration gene.

• No conclusion may be drawn about the parental genotypes based on the information given.

Baldness is a sex-linked trait. If we could see the pedigree chart for several more generations of the family illustrated here, we would expect

• more males to be bald

• more females to be bald

• no females to ever be bald

• an equal number of males and females that are color blind.

Based on the Law of Dominance, we would expect _____ percent of the offspring from this cross to have small teeth.

• 0%

• 25%

• 75%

• 100%

Start with the P generation with the following genotypes (AA x aa). Based on classical Mendelian inheritance, how will a cross between two homozygous parents, one dominant and one recessive, influence future generations?

• The F₁ generation will show an even split between the dominant phenotype and the recessive phenotype.

• The F₁ generation will all show the dominant trait and future crosses will continue to produce genotypes expressing the dominant trait.

• Although the F₁ generation will all show the dominant trait, the offspring will all be heterozygous and increase chances of future variation.

• The F₁ generation will show a mix of the dominant phenotype and recessive phenotype and over generations the recessive trait will increase in number.

The pedigree above shows a cross between an affected female and unaffected male for Huntington's disease. Huntington's disease is autosomal dominant. In this case, what is the chance that the two parents at the top have a child who carries the trait for huntington's, but does not show it.

• 0%

• 25%

• 50%

• 75%

• 100%

In the image, the squares represent males, the circles females. The darkened shapes represent those who are affected. The diagonal line represents deceased subjects.

What do the darkened squares represent?

• normal males

• normal females

• affected males

• deceased females

In the diagram, the top square and circle represent the _____________ generation.

• F1

• F2

• G

• P

In a classic experiment using pea shape, Mendel conducted two separate genetic crosses. In the first cross the parent plants were “true breeding” for pea shape; one had round peas ( R )and the other had wrinkled (r). The first cross produced a filial 1 generation of all round peas. In the second cross, Mendel bred plants from the filial 1 generation. This cross produced different results. Out of approximately 1000 plants, about 75% were round and 25% were wrinkled.

From these experiments, Mendel developed four hypotheses. They include all BUT....

• one heritable factor may be dominant and mask the other factor.

• any organism that "shows" a heritable factor must be homozygous.

• an organism has two "heritable factors", now called genes, one from each parent.

• a sperm or egg carries only one heritable factor for each trait in the offspring.

Both male and female gametes are created during the process of meiosis. The formation of male gametes or sperm is called spermatogenesis. After telophase II of spermatogenesis, there would be __________ male gametes created that are all genetically __________.

• 2; identical

• 2; different

• 4; identical

• 4; different