bio ch 12

A and B are independent events. The probability that A will happen is 1/4 and the probability that B will happen is also 1/4. What is the probability they will both happen?

1/16

In mice, the allele for black fur is dominant to the allele for brown fur. If a male homozygous black mouse is crossed with a female brown mouse, what proportion of the black F2 offspring do you predict will be homozygous?

1/3

At one gene locus in humans there are 2 alleles: one for curly hair and another for straight hair. Neither allele is dominant, and heterozygous individuals have wavy hair. At a second gene locus, 3 alleles control ABO blood type. The alleles at these 2 gene loci assort independently. A man with straight hair and A blood marries a woman with wavy hair and B blood. Their first child has straight hair and O blood. What is the probability that their next child will have wavy hair and blood type AB?

1/8

Cystic fibrosis is an inherited disease that affects breathing and digestion. It is caused by a single recessive allele. Two parents without cystic fibrosis have a child who has cystic fibrosis. What is the probability that their third child will be a boy with cystic fibrosis?

1/8

Cells from the fruit fly Drosophila melanogaster contain four pairs of chromosomes. What is the number of possible chromosome orientations in that cell?

16

In humans, brown eyes are dominant to blue eyes. If a blue-eyed man marries a brown-eyed woman whose mother has blue eyes, what is the expected genotypic ratio among the offspring?

1:1

In pea plants, the allele for round seeds is dominant to the allele for wrinkled seeds. At another gene locus, the allele for yellow seeds is dominant to the allele for green seeds. These two allele pairs assort independently. If a plant breeder crosses two plants that are both heterozygous at both gene loci, what proportion of the offspring will produce round, green seeds?

3/16

What would be a likely outcome if the alignment of maternal and paternal chromosomes during metaphase of meiosis did not adhere to Mendel's Law of Independent Assortment?

Alleles for genes would tend to be inherited together because chromosome pairs would align non-randomly.

The fact that maternal and paternal chromosome pairs line up randomly during metaphase of meiosis supports Mendel's

Law of Segregation

According to Mendel's Principle of Independent Assortment

each pair of alleles segregates independently of the other allele pairs.

Prior to the 20th century, the most common explanation of inheritance can best be described as

inheritance results from a blending of traits within fixed, unchanging species.

A trait is most likely to exhibit continuous variation if it is controlled by

many gene loci, each with several possible alleles.

You are tossing a six-sided die. Because you cannot roll both a 2 and a 5 on a single toss, these two events are called

mutually exclusive

The physical basis for the segregation of alleles when gametes are formed is

separation of homologous chromosomes during anaphase I followed by separation of sister chromatids during anaphase II.

The physical basis for the independent assortment of alleles when gametes are formed is

the independent alignment of homologous pairs during metaphase I.

According to Mendel's Principle of Segregation

the two alleles at each gene locus separate during gamete formation.