Biology Chapter 23

What are the chances that two individuals with wavy hair (an incomplete trait) will have a curly-haired child? Curly hair and straight hair exhibit incomplete dominance. -none -50% -75% -25%

25%

In guinea pigs, B = black, b = brown, S = short hair, s = long hair. Two heterozygous individuals reproduce. The expected results are: -9 black long hair, 3 black short hair, 3 brown long hair, 1 brown short hair. -9 brown short hair, 3 black long hair, 3 brown long hair, 1 black short hair. -9 black short hair, 6 black long hair, 3 brown long hair, 1 black short hair. -9 black short hair, 3 black long hair, 3 brown short hair, 1 brown long hair.

9 black short hair, 3 black long hair, 3 brown short hair, 1 brown long hair

Some plants fail to produce chlorophyll, due to a recessive trait. If we locate a pea plant that is heterozygous for this trait, self-pollinate it, and harvest the seeds, what are the likely phenotypes of the resulting offspring? -About one-half will be green and one-half white since that is the distribution of the genes in the parents. -About one-fourth will be white and three-fourths green since it is similar to a monohybrid cross. -About one-fourth will be green and three-fourths white since it is similar to a monohybrid cross. -All will be green with chlorophyll since that is the dominant trait.

About one-fourth will be white and three-fourths green since it is similar to a monohybrid cross.

In a Mendelian monohybrid cross involving two homozygous genotypes, the ____ generation is always completely heterozygous. -F2 -P -P2 -F1

F1

A man with AB blood type can have a child with type O. True or False?

False

In peas, yellow is dominant over green in seeds. With which of these is it best to cross a yellow-seeded pea plant to determine whether it is homozygous or heterozygous? -a pure yellow-seeded plant -a heterozygous yellow-seeded plant or a pure yellow-seeded plant -a heterozygous yellow-seeded plant -a green-seeded plant

a green-seeded plant

Alternative forms of a gene that influence the same trait and are found at the same location in homologous chromosomes are called: -incomplete dominance. -phenotypes. -alleles. -genotypes.

alleles

Mendel's law of segregation implies that the two members of an allele pair: -are distributed to the same gamete. -are assorted dependently. -are distributed to separate gametes. -are segregated pairwise.

are distributed to separate gametes

You have two true-breeding rose bushes, one with red flowers and one with white flowers. A cross between these two roses yields a bush with white flowers that have red splotches. What condition does this demonstrate? -codominance -incomplete dominance -environmental effects -polygenetic inheritance

codominance

The _____ indicates the gene combination of an individual. -genotype -loci -homozygous -phenotype

genotype

In a testcross, an organism with a dominant phenotype, but unknown genotype is crossed with which of the following to establish its genotype? -heterozygous -homozygous dominant -heterozygous dominant -homozygous recessive

homozygous recessive

Cold weather can change the ______ of a Himalayan rabbit. -phenotype -genotype -alleles -sex

phenotype

What genetic disorder is associated with the lack of an enzyme necessary for the normal metabolism of the amino acid phenylalanine? -phenylketonuria (PKU) -cystic fibrosis (CF) -sickle cell disease -Huntington disease

phenylketonuria (PKU)

Traits that are controlled by several sets or pairs of alleles, such as skin color and height in humans, are the result of what form of inheritance? -incomplete dominance -simple Mendelian inheritance -polygenic -codominance

polygenic

In which kind of cross could you expect to find ratios of 1:1:1:1 among the offspring? -one-trait test cross -dihybrid cross -monohybrid cross -two-trait test cross

two-trait test cross

Common fruit flies, Drosophila melanogaster, have been used as model organisms to study inheritance in animals for many years. Flies with the yellow body phenotype make no melanin. Look at the image above to see diagrams representing the "wild-type" and "yellow body" flies. In an experiment, Karen crossed a true-breeding line of wild-type flies with yellow body flies. All the offspring of those crosses were wild-type. Then Karen crossed the offspring with each other. She got 328 yellow body flies and 1014 wild-type flies. What is the probably inheritance pattern for the yellow body allele? -Wild-type is recessive to yellow body. -Yellow body is recessive to wild-type. -Wild-type and yellow body are incompletely dominant. -Wild-type and yellow body are codominant.

yellow body is recessive to wild-type