Week 1- Quizzes, Animations, Clicker questions Flashcards Preview

LS 7B- Genetics, Evolution, & Ecology > Week 1- Quizzes, Animations, Clicker questions > Flashcards

Flashcards in Week 1- Quizzes, Animations, Clicker questions Deck (49)
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1
Q

How do most cancers arise?

A., from a single mutations arising simultaneously in a cluster of cells

B., from a series of mutations that arise in the descendants of a single somatic cell

C., from multiple mutations arising simultaneously in a single cell

D., from mutations arising in a single cell that are then transmitted to other cells in the body

A

B., from a series of mutations that arise in the descendants of a single somatic cell

2
Q

How do mutations arise?

A., Mutations in cancer cells arise because they need to divide faster.

B., Mutations arise in a specific sequence where a mutation in one gene directly leads to a mutation in a specific second gene.

C., Mutations arise randomly and independent of other mutations in the cell. ,

D., Mutations arise simultaneously, where whole sets of mutations occur in a single event.

A

C., Mutations arise randomly and independent of other mutations in the cell.

3
Q

What effect does each successive mutation have on the colon cells in the example?

A., It causes them to leave the colon and spread to other tissues.

B., It causes them to divide more rapidly than normal cells.

C., It causes them to become non-colon cells.

D., In causes them to become larger and expand in the colon.

A

B., It causes them to divide more rapidly than normal cells.

4
Q

When p53 becomes mutant in cells already mutant for APC and Ras, what occurs?

A., These cells survive despite DNA damage and divide extremely rapidly.

B., These cells die.

C., These cells remain benign.

D., These cells expand their chromosome number to 53.

A

A., These cells survive despite DNA damage and divide extremely rapidly.

5
Q

_____ mutations are important to the evolutionary process; most cancers result from _____ mutations.

A. Somatic; heritable
B. Point; germ-line
C. Germ-line; heritable
D. Germ-line; somatic
E. Somatic; germ-line
A

D. Germ-line; somatic

6
Q

The number of new mutations in organisms following a round of genome replication:

A. generally decreases with larger genomes.

B. None of the answer options is correct.

C. generally increases with larger genomes.

D. is similar, independent of genome size.

E. is highest in bacteria.

A

C. generally increases with larger genomes.

7
Q

Which of the following statements concerning cancer and mutations is CORRECT?

A. Usually, multiple mutations are required in different genes to cause cancer.

B. None of the other answer options is correct.

C. Usually, a single mutation is all that is required to cause cancer.

D. Cancer can only occur with a mutation in a germ cell.

E. Cancer can only occur with a mutation in a somatic cell.

A

A. Usually, multiple mutations are required in different genes to cause cancer.

8
Q

Sites in the genome that are more susceptible to mutations than others are called:

A. hotspots.
B. noncoding DNA.
C. genes.
D. mutation spots.
E. risk factors.
A

A. hotspots.

9
Q

The definition of mutation is “any heritable change in the genetic material.” The qualifier “heritable” is necessary because:

A. most changes in the genetic material are harmful to the organism.

B. changes in the genetic material occur without regard to the needs of the organism.

C. most changes in the genetic material are repaired soon after they occur.

D. changes in the genetic material occur at random along the genome.

A

C. most changes in the genetic material are repaired soon after they occur.

10
Q

Prophase of meiosis I has some important differences from prophase of mitosis. These differences include: _________ pair, and _________ occurs.

A., chromatids; condensation

B., chromosomes; separation

C., homologous chromosomes; crossing over

D., homologous chromatids; separation

A

C., homologous chromosomes; crossing over

11
Q

During meiosis crossing over takes place between:

A., any two chromatids.

B., sister chromatids.

C., non-sister chromatids.

D., nonhomologous chromosomes.

E., nonhomologous chromatids.

A

C., non-sister chromatids.

12
Q

In anaphase I of meiosis, most of a chromosome is shaded dark, whereas a portion of what is in the circle is shaded light. Which of the following statements best explains the meaning of this shading?

A., The dark and light indicate homologous chromosomes.

B., The light part came from the homolog by crossing over.

C., The light part is a mixture of genes from both parental types.

D., The light and dark parts are different genes.

A

B., The light part came from the homolog by crossing over.

13
Q

When do sister chromatids separate in meiosis?

A. anaphase II
B. telophase I
C. anaphase I
D. metaphase II

A

A. anaphase II

14
Q

Which of the following is NOT true about gametes?

A. They are called eggs and sperm in animals.

B. They are formed by meiotic cell division.

C. They have half as many chromosomes as a somatic cell of the same individual.

D. They fuse to form a new organism during fertilization.

E. They are genetically identical to other gametes formed during meiosis.

A

E. They are genetically identical to other gametes formed during meiosis.

15
Q

Homologous chromosomes separate from each other in:

A. meiosis I.

B. They never separate from each other during any form of cell division.

C. meiosis II.

D. mitosis.

A

A. meiosis I.

16
Q

Which of the following is NOT a characteristic of meiotic cell division?

A. Cell division results in the formation of four daughter cells.

B. Daughter cells are genetically identical.

C. Cell division results in the production of gametes.

D. Cell division requires two rounds of nuclear division.

A

B. Daughter cells are genetically identical.

17
Q

Which one of the following BEST describes genotype-by-environment interactions?

A. The environment of an organism determines the genetic make-up of that organism.

B. Under certain circumstances, two organisms with identical genotypes have different phenotypes.

C. The genotype of an organism determines how that organism will behave in its environment.

D. Genetic and environmental factors combine to influence phenotype.

E. Under certain circumstances, two organisms with identical phenotypes have different genotypes.

A

D. Genetic and environmental factors combine to influence phenotype.

18
Q

The genotype of an organism constitutes its observable characteristics.

True

False

A

False

19
Q

An organism that has two different alleles of a given gene has a _____ genotype.

heteromorphic

heterozygous

diploid

merozygous

dizygous

A

heterozygous

20
Q

Harmful mutations are always quickly weeded out of a population.

False

True

A

False

21
Q

A phenotype always refers to something that you can see with your eyes, such as hair color or eye color.

False

True

A

False

22
Q

In a homozygous genotype:

both alleles for a given trait are the same, and the individual will be phenotypically dominant.

both alleles for a given trait are the same.

the two alleles for a given trait are different.

the individual will be phenotypically dominant.

the individual will be phenotypically recessive.

A

both alleles for a given trait are the same.

23
Q

What is an allele?

a group of unrelated genes seen in true-breeding stock

a circular strand of DNA capable of self-replication

a spontaneous mutation

one of several different forms of a gene

the external appearance of an organism

A

one of several different forms of a gene

24
Q

Huntington’s disease is a devastating neurological disorder. If a child of an affected parent receives one copy of the Huntington allele, he or she will develop Huntington’s disease. Thus, Huntington’s disease is considered _____ trait.

a neutral

a reciprocal

either a neutral or recessive

a dominant

a recessive

A

a dominant

25
Q

In genetic crosses, the symbol Aa refers to a:

morphotype.

phenotype.

holotype.

archetype.

genotype.

A

genotype

26
Q

Which of the following genotypes would result in a true-breeding stock?

Aa, but not AA or aa

AA or Aa or aa

AA, but not Aa or aa

aa, but not Aa or AA

AA or aa, but not Aa

A

AA or aa, but not Aa

27
Q

True-breeding plants are typically heterozygous for most genes.

True
False

A

False

28
Q

A testcross involves crossing with a(n) _____ individual and is used to determine the _____ of the tested parent.

homozygous recessive; genotype

homozygous recessive; phenotype

homozygous dominant; phenotype

F2 offspring; parental genotype

homozygous dominant; genotype

A

homozygous recessive; genotype

29
Q

A Punnett square can be used to interpret the results of a testcross.

False
True

A

True

30
Q

The use of the multiplication rule requires which of the following?

The events being considered are associated.

The events being considered occur independently.

A

The events being considered occur independently.

31
Q

The addition rule requires which of the following?

Two outcomes (such as having the genotype BB or Bb) are mutually exclusive in an organism.

More than one outcome (such as two different genotypes resulting in black fur) can occur simultaneously in an organism.

A

Two outcomes (such as having the genotype BB or Bb) are mutually exclusive in an organism.

32
Q

Animals that sexually reproduce are _____ and produce _____ gametes.

diploid; haploid

diploid; diploid

haploid; diploid

haploid; haploid

A

diploid; haploid

33
Q

In his cross, what did Mendel do?

A., He studied traits controlled by a single gene.

B., He did not use pure-breeding plants in his crosses.

C., He used plants that were heterozygous in his initial crosses.

A

A., He studied traits controlled by a single gene.

34
Q

In Mendel’s crosses:

A., the plants he started with had two alleles of each gene.

B., the plants he started with were heterozygous.

C., the F1 plants had a 3:1 ratio of yellow to green

A

A., the plants he started with had two alleles of each gene.

35
Q

How did Mendel make crosses with his plants?

A., He planted the seeds of each type together, and they grew into a single plant.

B., He cut the peas in half and combined them to grow a single plant.

C., He grew plants from seeds and fertilized the ovules of one plant with the pollen from another.

D., He allowed the pea plants to intertwine during growth to allow fertilization.

A

C., He grew plants from seeds and fertilized the ovules of one plant with the pollen from another.

36
Q

When Mendel crossed yellow peas with green peas, the next generation was all yellow. How is this explained?

A., Mendel used the pollen from the yellow plant in the cross, and the pollen is what determines the trait in the offspring.

B., The parental plants pass one of their two alleles on to the offspring which is heterozygous, and the A allele is dominant to the a allele.

C., The offspring didn’t get enough sunlight and so turned yellow.

A

B., The parental plants pass one of their two alleles on to the offspring which is heterozygous, and the A allele is dominant to the a allele.

37
Q

When the F1 plants are allowed to self fertilize, they produced both yellow and green peas in the next generation. How is this explained?

A., Three quarters of the offspring are homozygous and are yellow, and the other quarter of the offspring are heterozygous and are green.

B., In the F1 heterozygotes, the alleles segregate from each other when gametes form and then combine to make homozygotes and heterozygotes offspring.

C., The yellow peas are all heterozygous and the green peas are all homozygous.

D., The a allele is dominant, and heterozygotes for a are green.

E., All of the choices are correct.

A

B., In the F1 heterozygotes, the alleles segregate from each other when gametes form and then combine to make homozygotes and heterozygotes offspring.

38
Q

The principle of independent assortment holds that:

A., in heterozygotes, half the gametes will get one allele, and the other half will get the second allele.

B., the pattern of inheritance of one trait does not influence the pattern of inheritance of another trait.

C., during fertilization, haploid gametes join to create a diploid zygote.

D., in heterozygotes, the phenotype will be determined by the dominant allele.

A

B., the pattern of inheritance of one trait does not influence the pattern of inheritance of another trait.

39
Q

For an individual who is heterozygous for two genes, Aa and Bb, what does independent assortment predict?

A., Offspring inheriting the dominant (A) allele of the first gene are equally likely to inherit either the dominant (B) or the recessive (b) allele of the second gene.

B., Offspring inheriting the dominant allele (A) of the first gene will also inherit the dominant (B) allele of the second gene.

C., Offspring inheriting the recessive allele (a) of the first gene will inherit the dominant allele (B) of the second gene.

A

A., Offspring inheriting the dominant (A) allele of the first gene are equally likely to inherit either the dominant (B) or the recessive (b) allele of the second gene.

40
Q

In a cross between two individuals who are heterozygous for two traits determined by dominant and recessive alleles (Aa Bb), what is the expected ratio of offspring for the trait determined by the first gene (Aa)?

A., 9:3:3:1

B., 3:1

C., 1:1

D., 12:4:4:1

A

B., 3:1

41
Q

In a cross between two individuals who are heterozygous for two traits determined by dominant and recessive alleles (Aa Bb), what is the expected ratio of phenotypes for the traits determined by both genes?

A., 9:3:3:1

B., 3:1

C., 1:1

D., 12:4:4:1

A

A., 9:3:3:1

42
Q

When a 9:3:3:1 ratio of phenotypes is produced by a cross between two individuals, which phenotypes are present in the rarest class that is represented by only 1 of the 16 possible genotypes of offspring?

A., These offspring have the dominant phenotype of both traits.

B., These offspring have the dominant phenotype of one trait and the recessive phenotype of the other trait.

C., These offspring have the recessive phenotype of both traits.

A

C., These offspring have the recessive phenotype of both traits.

43
Q

Genes on different chromosomes _____ during meiosis. Genes that are very close together on the same chromosome are _____.

assort independently; linked

do not assort independently; linked

assort independently; unrelated

do not assort independently; unrelated

A

assort independently; linked

44
Q

The principle of independent assortment states that:

alleles of a gene pair assort independently of other gene pairs.

when gametes are formed, the two members of a gene pair will separate equally into gametes.

when gametes are formed, the two members of a gene pair assort together in gametes.

one set of alleles of a gene pair always assorts with the alleles of another gene pair.

A

alleles of a gene pair assort independently of other gene pairs.

45
Q

When one gene is able to modify the effect of a second gene, the phenomenon is known as:

epistasis.

segregation.

independent assortment.

simple dominance.

recessiveness.

A

epistasis

46
Q

While doing a pedigree analysis of a European royal family, you notice a disease in a female child of two healthy parents. There are also some cousins with the same genetic disease. If this disease is controlled by a single gene, then the MOST likely explanation for these observations is that the disease is:

a spontaneous mutation.

dominant and only seen in homozygous dominant individuals such as the daughter.

only seen in heterozygous individuals such as the daughter.

dominant and is seen in homozygous dominant or heterozygous individuals.

recessive and only seen in homozygous recessive individuals such as the daughter

A

recessive and only seen in homozygous recessive individuals such as the daughter

47
Q

A researcher is creating pedigrees for a trait he suspects to be dominant in humans. What are some of the likely features of his pedigrees for families with this trait?

All the offspring of a mating where one parent has the trait will themselves be affected.

None of the answer options is correct.

Only females will have this dominant trait.

The occurrence of mating between individuals with this trait will be high, because all dominant traits are common within any given population.

A

None of the answer options is correct.

48
Q

You are examining a human pedigree for a trait. You notice that the trait appears in every generation; is equally likely to occur in males and females; and, when one parent is affected, about half of his or her offspring are affected. The trait is MOST likely:

epistatic.

one that shows incomplete penetrance.

produced by multiple alleles.

dominant.

recessive.

A

dominant

49
Q

Which of the following is TRUE of incomplete penetrance?

Incomplete penetrance refers to cases in which individuals developing a particular disease (e.g., cancer or Alzheimer’s) lack the typical genotype for this disease.

Environmental factors do not influence penetrance.

Incomplete penetrance implies that some individuals will experience less severe forms of disease such as cancer or Alzheimer’s.

Gene interactions have been shown to result in incomplete penetrance in some cases.

A

Gene interactions have been shown to result in incomplete penetrance in some cases.