Chapter 19

1.

1 point

Mendel’s laws of inheritance govern:

the behavior of chromosomes during mitosis

the behavior of chromosomes during meiosis

the behavior of gametes during fertilization

the behavior of genes during recombination

2.

1 point

If a heterozygous organism shows a mutant phenotype, the mutant allele is:

Dominant

Blended

Lethal

Recessive

3.

1 point

Which of the following is the term for a cell produced by the fusion of two gametes?

Egg

Somatic cell

Germ cell

Zygote

4.

1 point

Mendel chose to study traits that are inherited in a discrete fashion. What does this mean?

He studied traits that came in distinct forms

He studied traits that affected only one part of his experimental organism.

He studied genes that he knew were on separate chromosomes

He study traits that did not affect organism viability

5.

1 point

Which of the following mutations is not typically found in a genetic screen?

Loss-of-functions mutations

Lethal mutations

Dominant mutations

Gain-of-function mutations

6.

1 point

Down syndrome, a human disease characterized by severe mental retardation, is caused by an error in meiosis, Which of the following is to blame?

Independent assortment

Nondisjunction

Gain-of-function mutation

Single nucleotide polymorphism

7.

1 point

Before the advent of recombination DNA technology, most genes were identified by observing the process disrupted when the gene was mutated.

True

False

8.

1 point

In humans, genes associated with red-green colorblindness and hemophilia are typically inherited together because:

the two genes produce gene products that interact with each other

the two genes are both recessive

the two genes are dominant

the two genes lie close together on the same together

9.

1 point

Which of the following statements is not true of SNPs and haplotype blocks?

SNPs are linked to their nearest neighbors, and in many cases these haplotype blocks have not been broken up by meiotic recombination.

Haplotype blocks represent allele combinations that were passed down from particular ancestors long ago

A single haplotype block consists of all the SNPs on a single human chromosome

10.

1 point

Which is NOT a function of crossing-over?

The creation of new combinations of maternal and paternal genes on individual chromosomes

The correct pairing of maternal and paternal chromosomes in the zygote

The proper segregation of maternal and paternal homologs

11.

1 point

Gregor Mendel, the father of genetics, studied inheritance in which of the following organisms?

Peas

Fruit flies

C. elegans

Dogs

E. coli

12.

1 point

In the first division of meiosis, the random assortment of maternal and paternal chromosomes into different cells has the potential to produce how many genetically different gametes in an organism with a haploid number of n chromosomes

2n

n^2

2^n

2/n

13.

1 point

If the blended inheritance theory were true, when true-breeding green peas are crossed with true-breeding yellow peas the result would be?

75% of the peas would be yellow, 25% would be green

Green Peas

Yellowish-green peas

Half green/half yellow peas

Yellow Peas

14.

1 point

In the first meiotic division, for each chromosome, allocation of the maternal or paternal or maternal homolog to one daughter cell or the other is random.

True

False

15.

1 point

Albinism is caused by a recessive mutation. If two albino parents have children with normal pigementation, you can conclude:

the parental mutations are in different genes

the parental mutations are in the same gene

You cannot make a conclusion based only on this information

16.

1 point

Which of the following statements accurately describes the process of meiosis?

Meiosis occurs by two rounds of cell division, without DNA replication

Meiosis begins with a single round of DNA replication, followed by two rounds of cell division

Meiosis begins with a single round of DNA replication, followed by a single round of cell division

Meiosis occurs by a single round of cell division, followed by DNA replication

17.

1 point

In a diploid organism loss of function mutations are usually recessive because:

They are complemented by gain of function mutations

They are so rare

The other, normal copy of the gene does the job

18.

1 point

An individual that possesses two identical alleles is said to be ________ for that trait?

Heterozygous

Homozygous

Homologous

Heterologous

19.

1 point

Which of the following statements does not describe the advantage of sexual reproduction?

Allows for parents to produce large numbers of offspring

Sexual reproduction can speed the elimination of deleterious alleles from a population

Reshuffling genes through sexual reproduction can help a species survive in an unpredictably variable environment

None of these

20.

1 point

Which of the following terms is used for the physical connections that correspond to crossovers between two non-sister chromatids?

Homologs

Chiasmata

Alleles

Bivalents

21.

1 point

A pedigree show the ______ of each family member for the trait of interest

Genotype

Phenotype

Chromosome

Wealth

22.

1 point

Gain-of-function mutations are usually _______.

Recessive

Dominant

23.

1 point

A diploid organism that reproduces sexually produces _____ gametes.

Somatic

Conjunctional

Haploid

Diploid

24.

1 point

Alleles that arose recently in evolutionary history:

tend to be found in a larger haplotype block

are not found in haplotype blocks

are found in multiple haplotype blocks

tend to be found in a smaller haplotype block

25.

1 point

Which of the following terms is used for a cell or organism that contains the wrong number of chromosomes?

Aneuploid

Diploid

Polyploid

Haploid

26.

1 point

Which of the following meiotic divisions produces haploid cells from diploid parent cells

Both of these

Meiosis I

Meiosis II

Neither of these

27.

1 point

Early in meiosis I, homologous chromosomes join to form bivalents, which contain _________ chromatids?

1

2

3

4

28.

1 point

When does recombination occur?

Meiosis I

Meiosis II

Mitosis S Phase

Mitosis M Phase

All of these

None these

29.

1 point

To identify mutant organisms of interest, scientists use:

a genetic screen

recombinant DNA technology

gel electrophoresis

Southern blots

30.

1 point

Any two humans differ by how many SNPs?

1 in every 100, 000

1 in every 1000 nucleotides

1 in every 1,000, 000

1 in every 10,000 nucleotides

31.

1 point

Which of the following statements describes a true-breeding variety of plants?

True-breeding plants can self-pollinate, but are unable to cross-pollinate other plants

When true-breeding plants self-pollinate, all of their offspring are of the same variety

When true-breeding plants self-pollinate, all of the possible variations in traits are visible in their offspring

When true-breeding plants self-pollinate, offspring display traits in a 3:1 ratio

32.

1 point

Each gamete caries a single allele for each character?

True

False

33.

1 point

Mendel crossed true-breeding plants producing yellow peas with true breeding plants producing green peas and found their offspring all had yellow peas. Which color allele is recessive?

Green

Yellow

34.

1 point

Which of the following statements describes a true mechanism that ensures that only one sperm fertilizes an egg?

A single receptor for a sperm cell exists on the egg

As the sperm enters the egg, the sperm releases hormones that make the egg membrane impermeable to other sperm

After fertilization of an egg by a sperm, the egg releases chemicals that inhibit the movement of nearby sperm

After fertilization of an egg by a sperm, the zona pellucida hardens, preventing other sperm from entering

35.

1 point

Which of the following describes the appearance of an organism?

Haploidy

Phenotype

Genotype

36.

1 point

Which of the following is the term for the variant versions of a gene?

Mutations

Homologs

Sister genes

Alleles