Meiosis Mitosis & Chromosome – Molecular Biology

Meiosis Mitosis & Chromosome – Molecular Biology

This exam covers meiosis mitosis and chromosome of molecular biology.


Glycolysis will produce all of the following except:

NADH

ATP

FADH2 – correct

Pyruvate


Which of the following would pass easily through a lipid bilayer?

Mg++

Water

Oxygen gas – correct

glucose

None of these


Exocytosis is used for all the following except:

Secretion of waste to the extracellular environment.

Secretion of insulin by cells of the pancreas.

Decreasing the amount of plasma membrane. – correct

Delivering aquaporin to the plasma membrane.


Which of the following would not be found in plant cells?

Central vacuole.

Endoplasmic reticulum.

Chloroplast.

Mitochondria

All of these are found in plant cells – correct


A chemist synthesizes glucose (C6H12O6) in which the oxygen atoms in the glucose are the isotope 18O. If a person were to eat this glucose and metabolize it completely by aerobic cellular respiration, where would the Oxygen-18 end up? Assume all other oxygen atoms are the lighter isotope (16O).

Exhaled, in carbon dioxide. – correct

Exhaled, in oxygen.

In their perspiration (i.e. in water).

Stored in triglycerides.

In the liver, as lactic acid.


In a plant cell, DNA would be found in:

Central vacuole.

Smooth ER.

Chloroplasts

Mitochondria.

Both (C) and (D). – correct


A reaction profile is shown below. The reaction could correspond to:

Reaction. Meiosis Mitosis & Chromosome - Molecular Biology

The overall reactions of glycolysis.

The overall reactions of the citric acid cycle.

Breaking a protein down into its amino acids.

Building starch from glucose – correct

A spontaneous reaction.


Cells maintain a higher concentration of Na+ ions on the outside of cells, and K+ on the inside. This is an example of:

Passive transport.

Facilitated diffusion.

Phagocytosis

Active Transport – correct

Osmosis


Which of the following molecules is in an ‘oxidized’ state? Choose all the correct options.

Glucose

Carbon dioxide – correct

NADP+ – correct


An organism’s traits are determined by the specific combination of inherited _____.

cells

Genes   – correct

proteins

chromatids


Which of the following events does not occur during some stages of interphase?

DNA duplication

organelle duplication

increase in cell size

separation of sister chromatids – correct


Separation of the sister chromatids is a characteristic of which stage of mitosis?

prometaphase

metaphase

anaphase – correct

telophase


Metaphase is characterized by ________.

alignment of chromosomes on the equator of the cell – correct

separation of the centromeres

cytokinesis

separation of sister chromatids


Which of the following is the correct order of events in mitosis?

Sister chromatids line up at the metaphase plate. The kinetochore becomes attached to the mitotic spindle. The nucleus reforms and the cell divides. Cohesin proteins break down and the sister chromatids separate.

The kinetochore becomes attached to the mitotic spindle. Cohesin proteins break down and the sister chromatids separate. Sister chromatids line up at the metaphase plate. The nucleus reforms and the cell divides.

The kinetochore becomes attached to the cohesin proteins. Sister chromatids line up at the metaphase plate. The kinetochore breaks down and the sister chromatids separate. The nucleus reforms and the cell divides.

The kinetochore becomes attached to the mitotic spindle. Sister chromatids line up at the metaphase plate. Cohesin proteins break down and the sister chromatids separate. The nucleus reforms and the cell divides. – correct


How is plant cell cytokinesis different from animal cell cytokinesis?

The contractile filaments found in plant cells are structures composed of carbohydrates; the cleavage furrow in animal cells is composed of contractile proteins.

Plant cells deposit vesicles containing cell wall building blocks on the metaphase plate; animal cells form a cleavage furrow. – correct

The structural proteins of plant cells separate the two cells; in animal cells, a cell membrane separates the two daughter cells.

Plant cells divide after metaphase but before anaphase; animal cells divide after anaphase.


At metaphase I, homologous chromosomes are connected only at what structures?

Chiasmata – correct

Recombination modules

Microtubules

Kinetochore


Meiosis usually produces ________ daughter cells.

Two haploid

Two diploid

Four haploid – correct

Four diploid


Which of the following is not true in regard to crossover?

Spindle microtubules guide the transfer of DNA across the synaptonemal complex. – correct

Nonsister chromatids exchange genetic material.

Chiasmata are formed.

Recombination nodules mark the crossover point.


Which of the following events happens at the conclusion of meiosis I?

Homologous chromosomes of a pair are separated from each other. – correct

The chromosome number per cell remains the same.

Sister chromatids are separated.

Four daughter cells are formed.


Which statement best describes the genetic content of the two daughter cells in prophase II of meiosis?

haploid with one copy of each gene

haploid with two copies of each gene – correct

diploid with two copies of each gene

diploid with four copies of each gene


During which of the following processes do sister chromatids separate from each other?

during meiosis I only

during meiosis II only

during both mitosis and meiosis I

during both mitosis and meiosis II – correct


The part of meiosis that is similar to mitosis is ________.

Meiosis I

Anaphase I

Meiosis II – correct

Interkinesis


Which of the following could be correct of the cell shown below?

Metaphase I

Metaphase I, 2n =6  – correct

Metaphase I, 2n=3

Metaphase II, 2n =6

Metphase II, 2n = 3

Metaphase of Mitosis, 2n=6

Metaphase of Mitosis, 2n = 3


The observable traits expressed by an organism are described as its ________.

Phenotype  – correct

genotype

alleles

zygote


A recessive trait will be observed in individuals that are ________ for that trait.

heterozygous

homozygous or heterozygous

Homozygous  – correct

diploid


If an individual is heterozygous for a particular trait  

each parent contributed a different allele for that trait. – correct

each parent contributed the same allele for that trait.

one parent contributed two different alleles for that trait.

one parent contributed two copies of the same allele for that trait.


Autosomal chromosomes

are chromosomes 1 through 22 in humans – correct

include the Y chromosome in humans.

include the X chromosome in humans.

are the sex chromosomes.

All answers are correct.


Assuming no gene linkage, in a dihybrid cross of AABB x aabb with AaBb F1 heterozygotes, what is the ratio of the F1 gametes (AB, aB, Ab, ab) that will give rise to the F2 offspring?

1:1:1:1 – correct

1:3:3:1

1:2:2:1

4:3:2:1


Mendel’s observation of the segregation of alleles in gamete formation has its basis in which of the following phases of cell division?

prophase I of meiosis

anaphase II of meiosis

metaphase II of meiosis

anaphase I of meiosis – correct


The individual with genotype AaBbCCDdEE can make many kinds of gametes. Which of the following correctly describes why this situation is possible?

recurrent mutations form new alleles

crossing over during prophase I leads to genetic variety

different possible assortment of chromosomes into gametes occurs – correct

there is a tendency for dominant alleles to segregate together


In tomatoes, there are two alleles for the height gene. The tall allele is dominant over the short allele. You cross a heterozygous plant with a homozygous recessive plant. What phenotypes do you expect in their offspring?

100% tall

50% tall and 50% short – correct

75% tall and 25% short

75% short and 25% tall

100% short


In pea plants, yellow pods are dominant to green pods. If you cross two heterozygous pea pods, what is the expected phenotypic and genotypic ratios of their offspring? Choose BOTH from the options below.

3 yellow pods: 1 green pod – correct

3 green pods: 1 yellow pod

all green pods

2 green pods: 2 yellow pods

2 YY: 2 yy

1 YY: 2 Yy: 1 yy– correct

3YY : 1 yy

1 YY : 3 Yy


Imagine you are performing a cross involving seed color in garden pea plants. What F1 offspring would you expect if you cross true-breeding parents with green seeds and yellow seeds? Yellow seed color is dominant over green.

100 percent yellow-green seeds

100 percent yellow seeds – correct

50 percent yellow, 50 percent green seeds

25 percent green, 75 percent yellow seeds


In snap dragons there are two alleles for the flower color gene: a red allele and a white allele. The red allele is incompletely dominant over the white allele, so that heterozygous flowers are pink. If you cross two pink flowers what is the expected phenotypic ratio?

75% red, 25% white

25% red, 50% pink, 25% white – correct

50% red, 25% pink, 25% white

100% red


A man with blood type A and woman with blood type B have a son who has type O blood. What can you conclude about the parents?

The both must be heterozygous  – correct

The man is heterozygous and the woman is homozygous

The man is homozygous and the woman is heterozygous


What are all the possible phenotypes and liklihoods of each phenotype in the children of a couple where one individual is heterozygous for type A and one is heterozygous for type B?

50% type A, 50% Type B,

50% type AB, 25% type A, 25% Type B

50% type AB, 50% Type O

25% type AB, 25% type A, 25% Type B, 25% Type O  – correct


Given the following genotypes for two parents, AABBCc × AabbCc, assume that all traits exhibit simple dominance and independent assortment. What proportion of the progeny of this cross will be expected to phenotypically resemble the first parent with the genotype AABBCc?

1/4

¾ – correct

3/8

1


Joe, a colorblind male has four children with Marie, who has no history of colorblindness in her family. Colorblindness is an X-linked recessive trait. What is the chance their sons will be color blind?

0% – correct

25%

50%

75%

100%


Martha is a female whose father is colorblind. If Martha is not colorblind, then what is her genotype?

Colorblindness is a recessive, x-linked trait.

X(N) X(N)

X(N) X(N) or X(N) X(n)

X(N) X(n) – correct

X(N) Y


In which of the following conditions could a daughter inherit color blindness?

Her mother is a carrier and father is colorblind – correct

Her mother is color blind, but her father is not

Neither her mother or father is colorblind

All of these could possibly produce a daughter who is colorblind


The pedigree shows inheritance of a sex-linked recessive trait. What is the chance that the next child of III-1 and III-2 will be color blind?

Females are represented by circles and males are represented by squares. Individuals with the trait are shaded black. 

Sex linked recessive.

0%

25% – correct

50%

75%

100%


The pedigree shows inheritance of an autosomal dominant trait. What is the genotype of individual 1?

Females are represented by circles and males are represented by squares. Individuals with the trait are shaded black.

Genotype

TT

Tt – correct

tt

TT or Tt


The pedigree shows inheritance of a sex-linked recessive trait. Which female can we be certain is a carrier?

Females are represented by circles and males are represented by squares. Individuals with the trait are shaded black.

Sex liked recessive. Meiosis Mitosis & Chromosome - Molecular Biology

III-6

II-4

I-2 – correct

IV-2


All of the following are correct about meiosis, except:

The first meiotic division reduces the chromosome number from 2n to n.

Spindles attach to centromeres during Metaphase I and Metaphase II.

Products of meiosis can differentiate into germ cells (sperm or oocytes).

Homologous chromosomes pair together (synapse) during Prophase II. – correct

“S phase” occurs only one time, but there are two cell divisions.


In Mendel’s pea plants, height is determined by the t locus. The dominant T allele produces tall plants, while the recessive t allele results in short plants. A homozygous tall plant is crossed with a short plant, then the F1 plants are self-fertilized. If 360 F2 plants are counted, how many are expected to be tall?

270. – correct

360.

240.

180.

90.


Human populations are approximately 50% male and 50% female. This is explained by:

Mendel’s Law of Segregation applied to male meiosis. – correct

Semi-conservative replication of DNA.

Independent alignment of paired homologous chromosomes in meiosis.

Mendel’s Law of Independent Assortment applied to female gametes.

The fact that YY individuals die early in development.


Which of the diagrams below shows a cell in a species with 2n=2 undergoing the first metaphase of meiosis?

Cell Species

A

B – correct

C

D

E


Red-green colorblindness is inherited as an X-linked recessive mutation.  A colorblind man marries a woman whose father was colorblind, although her own vision is normal. The man and woman are expecting a child. If the child is a girl, what is the probability that she will be colorblind?

.75

.5 – correct

1

0

.25


A dihybrid cross generates a phenotype ratio that is not9:3:3:1. Without any more information, you could hypothesize that:

Crossovers are required to generate recombinant gametes.

The two genes are located on the same chromosome.

Alleles of the two genes do not assort independently.

F1 individuals make more parental gametes than recombinant gametes.

All of these are possible. – correct


Two genes in the fruit fly are on different chromosomes. One gene has alleles C and c, while the other gene has alleles D and d. Two flies of genotype CcDd are crossed together. Assuming that c and d are recessive, what proportion of the offspring will have a phenotype that is different from their parents?

12/16

7/16 – correct

4/16

6/16

9/16


Which of the following is correct about meiosis?

After Telophase II, every nucleus contains two of every chromosome, one from each parent.

Crossing over occurs in Prophase II.

Just before Prophase II, the DNA undergoes replication.

The second division results in n -> n. – correct

Centromeres will divide in Metaphase I.


Mice have 2n=40 chromosomes in their somatic cells. The number of chromosomes in a mouse sperm cell and a mouse skin cell are, respectively:

10, 40.

40, 40.

4, 4.

2, 4.

20, 40. – correct


Mendel performed crosses between PP purple-flowered plants and pp white-flowered plants. The P allele is completely dominant to the p allele. Which of the following best describes the F1 plants from a PP x pp cross?

50% of the F1 plants have purple flowers, and 50% of the F1 plants have white flowers.

The F1 plants do not breed true for the purple flower trait. – correct

The F1 plants have flowers with a faint purple color (a blend of white and purple).

The flowers carry the dominant Pallele, but the leaves carry only the recessive p allele.

Each F1 plant has a mixture of purple flowers and white flowers.


Study the karyotype below. Choose the correct statement about this individual.

Karyotype. Meiosis Mitosis & Chromosome - Molecular Biology

They have down syndrome

They have klinefelter’s Syndrome – correct

They have Edward’s Syndrome

They have Turner’s Syndrome


Which recombination frequency corresponds to perfect linkage and violates the law of independent assortment?

0% – correct

25%

50%

75%


Which of the following statements regarding gene linkage is correct?

The closer two genes are on a chromosome, the lower the probability that a crossover will occur between them. – correct

The observed frequency of recombination of two genes that are far apart from each other has a maximum value of 100%.

All of the traits that Mendel studied—seed color, pod shape, flower color, and others—are due to genes linked on the same chromosome.

Linked genes are found on different chromosomes.


Which of the following statements would explain a testcross involving F1 dihybrid flies in which more parental-type offspring than recombinant-type offspring are produced?

The two genes are closely linked on the same chromosome. – correct

The two genes are linked but on different chromosomes.

Recombination did not occur in the cell during meiosis.

Both of the characters are controlled by more than one gene.


In tomatoes, a heterozygous plant with normal fruit and purple stems is crossed with a recessive plant having fasciated fruit and green stems (test cross). The following distribution of offspring is observed:

normal fruit, purple stems 38.5%

fasciated fruit, green stems 38.5%

normal fruit, green stems 11.5%

fasciated fruit, purple stems 11.5%

What is the recombination frequency? Enter the percentage, without the percentage sign. For example, enter “25” for “25%”.

23 (with margin: 0) – correct


Analyze the genetic map below. Which of the following statements is true?

Genetic map

Recombination of the body color and red/cinnabar eye alleles will occur more frequently than recombination of the alleles for wing length and aristae length.

Recombination of the body color and aristae length alleles will occur more frequently than recombination of red/brown eye alleles and the aristae length alleles.

Recombination of the gray/black body color and long/short aristae alleles will not occur.

Recombination of the red/brown eye and long/short aristae alleles will occur more frequently than recombination of the alleles for wing length and body color. – correct


If you were to perform a test cross between the heterozygous gray body and red eyed flies with homozygous recessive, black body and cinnabar eyes, what percentage of the offspring would you expect to be recombinants?

Cross Test. Meiosis Mitosis & Chromosome - Molecular Biology

0%

9% – correct

50%

48.5%

57.5%

106%


Imagine a species with three loci thought to be on the same chromosome. The recombination rate between locus A and locus B is 35%, and the recombination rate between locus B and locus C is 33%. Predict the recombination rate between A and C.

The recombination rate between locus A and locus C is either 2% or 68%.

The recombination rate between locus A and locus C is probably 2%.

The recombination rate between locus A and locus C is either 2% or 50. – correct

The recombination rate between locus A and locus C is either 2% or 39%.


Which of the following statements about nondisjunction is true?

Nondisjunction only results in gametes with n+1 or n–1 chromosomes.

Nondisjunction occurring during meiosis II results in 50 percent normal gametes. – correct

Nondisjunction during meiosis I results in 50 percent normal gametes.

Nondisjunction always results in four different kinds of gametes.


Which of the following statements is generally true of aneuploidies in newborns?

A monosomy is more frequent than a trisomy.

Monosomy X is the only viable monosomy known to occur in humans. – correct

Human aneuploidy usually conveys an adaptive advantage in humans.


Study the karyotype below. Choose the correct statement about this individual.

Karyotype. Meiosis Mitosis & Chromosome - Molecular Biology

They have down syndrome

They have klinefelter’s Syndrome – correct

They have Edward’s Syndrome

They have Turner’s Syndrome


In agriculture, polyploid crops (like coffee, strawberries, or bananas) tend to produce ________.

more uniformity

more variety

larger yields – correct

smaller yields


Generally, only female cats have the tortoiseshell phenotype for fur color. Which of the following statements explains this phenomenon?

A male inherits only one allele of the X-linked gene controlling hair color. – correct

The Y chromosome has a gene blocking orange coloration.

Multiple crossovers on the Y chromosome prevent orange pigment production.


In which of the following scenarios was the transformation principle observed in Griffith’s experiment?

The S cells are lethal to the mice

The R cells are lethal to the mice

The heat killed R cells mixed with S cells are lethal to the mice

The heat killed S cells mixed with R cells kill the mice – correct


Predict the results of Avery and McLeod’s experiment if protein was the genetic material.  In which samples would transformation still occur?

Each sample has heat-killed S cells and living R cells plus one of the following enzymes.

The sample treated with an enzyme to degrade DNA (DNAse

The sample treated with an enzyme to degrade RNA (RNAse) – correct

The sample treated with an enzyme to degrade protein (protease)


Which of the follow is true based on Cargaff’s rules?

A + T = G + C

A + G = T + C – correct

A + G = 1

A + T = 50%


Which experimental technique was used to demonstrate that DNA has a double helix structure?

X-ray crystallography – correct

Nuclear Magnetic Resonance Imaging

Gel elecropherisis

DNA sequencing


If DNA of a particular species was analyzed and it was found that it contains 14 percent G, what would be the percentage of T?

Do not include the % sign in your answer.


Match each of the following characteristics to DNA, RNA or both.

Nucleic Acids

              Both

made up of nucleotides containing the sugar deoxyribose, a phosphate, and a nitrogenous base

              DNA

nitrogenous bases in the nucleotides are Adenine (A), guanine (G), cytosine (C), and uracil (U)

              RNA

nitrogenous bases in the nucleotides are Adenine (A), guanine (G), cytosine (C), and thymine (T)

              DNA

made up of nucleotides containing the sugar ribose, a phosphate, and a nitrogenous base

              RNA

Single Stranded

              RNA

double helix structure

              DNA

A always pairs with T; G always pairs with C

              DNA

A always pairs with U; G always pairs with C

              RNA


DNA is negatively charged. During gel elecrophoresis, DNA is pulled through the gel towards the positively charged electrode. This process seperates DNA fragments based on Size .

Answer 1:

negatively

Answer 2:

positively

Answer 3:

Size


What is the difference between a terminator nucleotide (ddNTP) and a natural DNA nucleotide (dNTP)?

The ddNTP has a ribose sugar and the dNTP has a deoxyribose sugar

The ddNTP has an extra phosphate on the 5′ carbon

The ddNTP is missing a hydroxyl group on the 3′ carbon – correct

Use of ddNTPs speeds up the rate of DNA synthesis


In eukaryotes, what is the DNA wrapped around?

single-stranded binding proteins

sliding clamp

polymerase

histones – correct


Which of the following is a purine?

Purine. Meiosis Mitosis & Chromosome - Molecular Biology

A – correct

B

C

D


Match the following proteins involved in DNA replication with their function.

creates phosphodiesters bonds between the 3′-OH group of a DNA strand and the 5′-phosphate group of a new nucleotide

              Ligase – correct

creates a break in the DNA strand to relieve tension

              Helicase – correct

creates covalent bonds to join Okazaki fragments

              Ligase – correct

adds repetitive sequences the ends of a linear chromosome

              Telomerase – correct

synthesizes RNA oligonucleotides without the need for an initial 3′-OH

              Primase – correct

prevent denatured DNA strands from re-annealing to one another

              Single Stranded Binding Proteins – correct

breaks the hydrogen bonds between the strands of dsDNA

              Helicase – correct


Which of the following explains why there is a leading and lagging strand?

The semi-conservative nature of DNA replication

Interference caused by the primase enzyme

The 5′ -> 3′ polarity restriction of DNA Polymerase – correct

The circular structure of bacterial chromosomes


Match the following to label the image of the replication fork.

DNA structure. Meiosis Mitosis & Chromosome - Molecular Biology

Correct Answers

A

              5′

B

              3′

C

              5′

D

              3′

E

              5′


The initial mechanism for repairing nucleotide errors in DNA is ________.

mismatch repair

DNA polymerase proofreading – correct

nucleotide excision repair

thymine dimers


You have isolated an E. coli mutant which grows very slowly. Upon further investigation, you discover that while DNA replication is successful in this mutant, it occurs much slower than in the wild type E. coli. Which enzyme would you suspect is mutated?

Helicase

Sliding Clamp – correct

Single stranded binding proteins

Primase

Ligase


Suppose a 100-base-pair, double-stranded DNA molecule consists of 15% thymine bases. How many total hydrogen bonds are holding the two strands together?

270


Homepage