Bio 20A Final Study Guide

What fraction of the offspring of BbDdgg and BbDdGg parents will have the same phenotype as the first parent?

- 3/4

- 9/16

- 3/16

- 9/64

- 1/2

- 9/32

9/32

This question concerns three linked genes. Bubba's genotype is Bb Dd Ee . His parents' genotypes were bbDDEE and BBddee. In the absence of recombination, Bubba is capable of producing which of the following gametes?

- bDE and Bde

- BDe and bdE

- bDe and BdE

- BDE, BdE, bDE, BDe, bdE, Bde, bDe, bde

- BB, bb, DD, dd, EE and ee

- Bb, Dd and Ee

bDE and Bde

Independent assortment occurs during (check all that apply):

-anaphase of meiosis II

-anaphase of meiosis I

-anaphase of mitosis

-metaphase of mitosis

-metaphase of meiosis II

-metaphase of meiosis I

metaphase of meiosis I

DNA wrapped around an octamer of histones H2A, H2B, H3 and H4 is a _____________

nucleosome

Match the terms with their definitions.

Terms:

-Centromere

-Chromatin

-Chromatid

-Sister chromatids

Def:

-a generic term that is used to refer to DNA plus associated proteins

-a highly condensed chromosome that is visible during mitosis or meiosis

-the region of a chromosome at which the kinetochore assembles

-a highly condensed pair of replicated chromosomes

Centromere-the region of a chromosome at which the kinetochore assembles

Chromatin-a generic term that is used to refer to DNA plus associated proteins

Chromatid-a highly condensed chromosome that is visible during mitosis or meiosis

Sister chromatids-a highly condensed pair of replicated chromosomes

DNA replication occurs during:

-S phase

-G0

-M phase

-prophase

-G1

-G2

S phase

Match the terms with the most accurate definitions

-Chromosome

-Kinetochore

-Homologous chromosomes

-a pair of chromosomes in diploid cells that contain the same genes, but the alleles may be different

-an entire DNA double helix plus associated proteins

-A complex of proteins assembled at the centromere to which spindle microtubules attach

Chromosome-an entire DNA double helix plus associated proteins

Kinetochore-A complex of proteins assembled at the centromere to which spindle microtubules attach

Homologous chromosomes-a pair of chromosomes in diploid cells that contain the same genes, but the alleles may be different

When a plant with light blue flowers is self-crossed, it has 16 progeny with light blue flowers and 5 progeny with white flowers. This is probably an example of:

-polygenic inheritance

-environmental effects

-complete dominance

-crossing over

-incomplete dominance

complete dominance

Different, unlinked autosomal genes control fur color and eye color in bears. The brown allele of the fur color gene is dominant to the blonde allele. The black allele of the eye color gene is dominant to the hazel allele. Two bears - Bruno and Ursula - are heterozygous for both the fur and eye color genes. What fraction of Bruno and Hazel's cubs will have brown fur and hazel eyes?

-9/16

-all of them will have brown fur and hazel eyes

-1/2

-1/4

-1/16

-3/4

-3/16

3/16

What fraction of the offspring of AaBbCc and AaBbCc parents will have the genotype AaBBCc?

- 3/4

- 3/16

- 9/16

- 1/8

- 1/2

- 1/4

- 1/16

1/16

Homologous chromosomes are separated during ___________ (check all that apply)

-anaphase of meiosis I

-telophase of meiosis II

-anaphase of meiosis II

-anaphase of mitosis

-prophase of meiosis I

anaphase of meiosis I

Meiosis II produces:

-diploid cells with replicated chromosomes

-haploid cells with replicated chromosomes

-diploid cells with unreplicated chromosomes

-haploid cells with unreplicated chromosomes

-somatic cells

haploid cells with unreplicated chromosomes

Match the genetic disease with the corresponding mutation:

-Hemophilia A

-Tay Sachs Disease

-Sickle Cell Disease

-Cystic Fibrosis

-mutation in gene encoding ß globin protein

-mutation in a gene encoding a lysosomal hydrolase

-mutation in gene encoding Factor VIII

-mutation in a gene encoding a chloride transport protein

Hemophilia A-mutation in gene encoding Factor VIII

Tay Sachs Disease-mutation in a gene encoding a lysosomal hydrolase

Sickle Cell Disease-mutation in gene encoding ß globin protein

Cystic Fibrosis-mutation in a gene encoding a chloride transport protein

During mitosis, chromosomes begin to condense during

prometaphase:

-telophase

-prophase

-anaphase

-cytokinesis

-metaphase

prophase

Mendel's dihybrid crosses led him to propose:

-that genes encode proteins

-the principle of independent assortment

-the principle of incomplete dominance

-the principle of segregation

-that DNA replication is semi-conservative

the principle of independent assortment

Which of the following are possible interpretations of a genetic test for BRCA1 and 2 mutations? Check all that apply

-The patient will definitely develop breast or ovarian cancer

-The patient will not develop breast or ovarian cancer

-The patient may not have an increased risk of developing breast or ovarian cancer

-The patient has an increased risk of developing breast or ovarian cancer

-The patient may not have an increased risk of developing breast or ovarian cancer

-The patient has an increased risk of developing breast or ovarian cancer

Down syndrome can result from which of the following? (check all that apply)

-nondisjunction during meiosis II

-a mutation in a chloride transport protein

-nondisjunction during meiosis I

-a mutation in a DNA repair enzyme

-a mutation in a lysosomal hydrolase

-nondisjunction during meiosis II

-nondisjunction during meiosis I

Place the following events of meiosis in the order in which they occur.

Earlier

Segregation of alleles

Independent Assortment

DNA replication

Separation of sister chromatids

Recombination

Later

-DNA replication

-Recombination

-Independent Assortment

-Segregation of alleles

-Separation of sister chromatids

Sister chromatids are separated during ___________ (check all that apply)

-anaphase of meiosis II

-binary fission

-anaphase of meiosis I

-anaphase of mitosis

-anaphase of meiosis II

-anaphase of mitosis

Meiosis I produces:

-Haploid cells with replicated chromosomes

-Diploid cells with unreplicated chromosomes

-Diploid cells with replicated chromosomes

-Gametes

-Haploid cells with unreplicated chromosomes

Haploid cells with replicated chromosomes

Match each of the following genetic disorders with the appropriate category

-Sickle Cell Disease

-Huntington Disease

-Down Syndrome

-Hemophilia A

-Chromosome disorder

-Autosomal dominant disorder

-Autosomal recessive disorder

-X-linked recessive disorder

Sickle Cell Disease-Autosomal recessive disorder

Huntington Disease-Autosomal dominant disorder

Down Syndrome-Chromosome disorder

Hemophilia A-X-linked recessive disorder

A diploid cell in G1 of the cell cycle has 32 DNA double helices. How many pairs of homologous chromosomes are present in the organism from which this cell was obtained?

IMPORTANT NOTE: your answer must be in the form of only a number, not a word, phrase or explanation. For example, 10 would be an appropriate answer, but ten, 10 chromosomes, 10 homologous chromosomes, 10 pairs, or ten pairs would not. No credit will be given for any answers that are not in the proper format.

16

This question deals with a human genetic disease caused by an X-linked recessive mutation. Jack and Jill are both healthy. Both Jill's father and Jack's father had the disease but their mothers were healthy. What is the probability that one of Jack and Jill's daughters will have the disease?

0

1

1/4

1/2

1/16

3/4

0

E. coli and other prokaryotic cells reproduce asexually via:

-meiosis

-either mitosis or meiosis

-binary fission

-mitosis

binary fission

During mitosis, spindle microtubules attach to the ________ of chromosomes.

-nucleosomes

-axonemes

-centrosomes

-telomeres

-kinetochores

kinetochores

Cell cycle checkpoints ensure that:

-sister chromatids are properly aligned on the metaphase plate prior to anaphase

-all of the above

-DNA has been replicated prior to division

-DNA damage is repaired prior to DNA replication

-a cell has grown sufficiently prior to division

all of the above

Which of the following kinds of cells divide by binary fission?

-plant cells

-human cells

-bacteria

bacteria

What would happen when a cell undergoing mitosis is fused with a cell in G1?

-Both cells would enter interphase

-The G1 cell would immediately enter mitosis

-The M cell would enter G1, the G1 cell would enter mitosis

-The M cell would immediately enter G1

-Both cells would enter S phase

-The G1 cell would immediately enter mitosis

Match each of the following to the corresponding stage of the cell cycle:

Stages:

-S phase

-Prophase

-anaphase

-telophase

-metaphase

-prometaphase

-Cytokinesis

-Chromosomes begin to condense

-nuclear envelope reforms

-DNA replication

-interphase microtubules break down

-S phase

-the cell splits in two

-sister chromatids have been lined up at the metaphase plate

-Chromatids pulled toward opposite poles of the cell

-mitotic spindle breaks down

-microtubules attach to the kinetochore

S phase-DNA replication

Prophase-Chromosomes begin to condense; interphase microtubules break down

anaphase- S phase; Chromatids pulled toward opposite poles of the cell

telophase-mitotic spindle breaks down; nuclear envelope reforms

metaphase-sister chromatids have been lined up at the metaphase plate

prometaphase-microtubules attach to the kinetochore

Cytokinesis-the cell splits in two

Interphase includes which of the following stages of the cell cycle? Check all that apply

-S

-M

-G1

-G2

-S

-G1

-G2

The term "chromatid" refers to:

-DNA wrapped around an octamer of histone proteins

-DNA and associated proteins

-the ends of a chromosome

-the complex of proteins that assembles at the centromere during mitosis

-a highly condensed chromosome that is visible during mitosis or meiosis

a highly condensed chromosome that is visible during mitosis or meiosis

A eukaryotic cell in G1 has 10 DNA double helices. If this cell underwent mitosis, how many DNA molecules (i.e. DNA double helices) would be present in the cell during prophase?

-40

-none of the above

-20

-10

-5

20

A cell that does not divide for an extended period is in _______

-G0

-S

-G2

-big trouble

-G1

G0

The nucleosome:

-is the fundamental unit of chromatin structure

-is the ribosome factory of eukaryotic cells

-is the interior of the nucleus

-none of the above

-is a microtubule organizing center

is the fundamental unit of chromatin structure

A mutation prevents the destruction of cyclin during the cell cycle. The most likely effect of this mutation would be:

-none of the above

-the cell would not exit mitosis

-rapid, unregulated cell division

-cancer

-all of the above

the cell would not exit mitosis

Homologous chromosomes are separated during ___________ (check all that apply)

anaphase of meiosis II

anaphase of meiosis I

anaphase of mitosis

telophase of meiosis II

prophase of meiosis I

anaphase of meiosis I

Which of the statements about homologous chromosomes are true? Check all that apply

They carry the same genes in the same order

The versions (alleles) of the genes they carry may be different

Homologous chromosomes are separated during anaphase of mitosis

Sister chromatids are homologous

They have identical DNA sequences

-They carry the same genes in the same order

-The versions (alleles) of the genes they carry may be different

Meiosis I produces:

Diploid cells with unreplicated chromosomes

Diploid cells with replicated chromosomes

Haploid cells with replicated chromosomes

Haploid cells with unreplicated chromosomes

gametes

Haploid cells with replicated chromosomes

Sources of genetic variation for organisms that reproduce sexually include:

independent assortment of chromosomes

random fusion of gametes

recombination

mutation

all of the above

all of the above

Which of the following statements are false?

-Multicellular organisms are always composed of diploid cells

-Meiosis leads to the production of haploid gametes

-The fusion of haploid gametes results in the formation of a diploid cell

-Some haploid cells can reproduce via mitosis.

-none of the above

Multicellular organisms are always composed of diploid cells

Meiosis II produces:

-haploid cells with unreplicated chromosomes

-haploid cells with replicated chromosomes

-diploid cells with unreplicated chromosomes

-diploid cells with replicated chromosomes

-somatic cells

haploid cells with unreplicated chromosomes

Sister chromatids are separated during ___________ (check all that apply)

-anaphase of mitosis

-anaphase of meiosis II

-anaphase of meiosis I

-binary fission

-anaphase of mitosis

-anaphase of meiosis II

Independent assortment occurs during (check all that apply):

-metaphase of meiosis I

-metaphase of meiosis II

-metaphase of mitosis

-anaphase of meiosis I

-anaphase of meiosis II

-anaphase of mitosis

metaphase of meiosis I

A diploid cell in G1 has 5 pairs of homologous chromosomes. If this cell underwent meiosis, how many DNA molecules (i.e.DNA double helices) would be present in each gamete after the completion of meiosis?

- 5

- 10

- 20

- 40

- none of the above

5

You flip a coin three times and it comes up heads each time. A friend flips a coin 3 times and it comes up tails each time. What is the probability that both you and your friend will both come up tails on the next toss?

- 1

- 1/2

- 3/4

- 1/4

- 0

1/4

Consider the following cross:

P: AABBCC x aabbcc

F1: AaBbCc

Genes A, B and C are linked. In the absence of recombination, what gametes can be produced by the F1 progeny? Hint: draw out the chromosomes of the parents and their progeny before answering this question.

-ABC, abc, ABc, abC, AbC, aBc, aBC and Abc

-not enough information to tell

-ABC and abc

-AABBCC and aabbcc

-AAA, BBB, CCC, aaa, bbb and ccc

ABC and abc

The segregation of alleles occurs during which of the following? Check all that apply

- anaphase of mitosis

- anaphase of meiosis I

- anaphase of meiosis II

- telophase of meiosis II

- metaphase of meiosis I

anaphase of meiosis I

Which following statements about the diagram shown below are true? Check all that apply. Note that the letters are used to mark the chromosomes; they do not refer to alleles/genes carried on the chromosomes

-A and B are sister chromatids

-The image is of a cell in metaphase of meiosis II

-The image is of a cell in metaphase of meiosis

-The image is of a cell in metaphase I of meiosis I

-A and B are identical; A and D are homologous

-A and E are different; E and F are identical.

-A and B are homologous; A and D are identical

-A and B are sister chromatids

-The image is of a cell in metaphase I of meiosis I

-A and B are identical; A and D are homologous

-A and E are different; E and F are identical.

Which of the following could account for incomplete dominance?

sex-linkage

polygenic inheritance

environmental effects

linkage

the product of a gene is present in limited quantities

the product of a gene is present in limited quantities

In a cross AaBbCcDd x AaBbCcDd, what is the probability that one of the offspring will have the genotype aaBBCCDd? Assume the genes are unlinked.

1/32

1/16

1/128

1

1/64

1/128

Match each of the following with the correct definition:

-dominant

-autosome

-genotype

-phenotype

-the appearance of an organism

-a chromosome other than a sex chromosome

-the allele that determines the appearance of an organism

-the genetic makeup of an organism

dominant-the allele that determines the appearance of an organism

autosome-a chromosome other than a sex chromosome

genotype-the genetic makeup of an organism

phenotype-the appearance of an organism

A male mouse with brown fur is crossed to a female mouse with white fur. All the male progeny have white fur while all the female progeny have brown fur. What is the most likely explanation for these data? Assume that the data are highly reproducible and large numbers of progeny were examined.

-The brown allele is dominant

-The brown allele is recessive

-The coat color gene is X-linked

-The coat color gene is autosomal

-The female parent is homozygous for the white allele

-The brown allele is dominant

-The coat color gene is X-linked

-The female parent is homozygous for the white allele

The purple (P) allele of a flower color gene is dominant to the white (p) allele. If two heterozygous plants are crossed, ____ % of their progeny will have purple flowers

75%

Black fur in mice (B) is dominant to brown fur (b). Short tails (T) are dominant to long tails (t). Of 32 progeny of the cross BbTt x BbTt, approximately how many will have brown fur and short tails? (assume the genes are not linked)

- 16

- 18

- 0

- 32

- 6

6

Given the parents AABBCc x AabbCc, what proportion of the progeny will phenotypically resemble the first parent (assuming the genes involved are on different chromosomes)?

- 1/4

- 9/16

- 3/4

- all of them

- 3/16

- 0

- 1/2

3/4

Two parents are healthy carriers of the mutations that cause sickle-cell disease and cystic fibrosis. What fraction of their children will have sickle cell disease and cystic fibrosis. The genes that cause the two diseases are unlinked.

- 1/16

- 3/4

- 3/16

- 1/4

- 9/16

- 1/2

1/16

A healthy man and a healthy woman have a son. The woman's father had hemophilia. What is the probability that their son will also have hemophilia?

- 75%

- 0%

- 25%

- 50%

- 100%

50%

Which of the following genetic diseases are caused by an autosomal recessive mutation? Check all that apply

Huntington's Disease

sickle cell disease

Tay-Sachs Disease

Hemophilia A

sickle cell disease

Tay-Sachs Disease

Mutations in a gene encoding a chloride transport protein cause:

- Cystic fibrosis

- Tay Sachs disease

- Sickle cell disease

- Hemophilia

- Huntington's disease

- Cystic fibrosis

________ is a chromosome disorder that can be caused by meiotic nondisjunction.

Down Syndrome

Which of the following statements about genetic testing for BRCA1 and 2 mutations are true? (check all that apply)

-it will reveal if a woman will definitely develop breast or ovarian cancer

-it can rule out the possibility that a woman will develop breast or ovarian cancer

-is recommended for individuals who belong to certain ethnic groups or have a family history of breast or ovarian cancer

-it may reveal if a woman has an elevated risk of developing breast or ovarian cancer

-is recommended for individuals who belong to certain ethnic groups or have a family history of breast or ovarian cancer

-it may reveal if a woman has an elevated risk of developing breast or ovarian cancer