Question 1

Which of the following might result in a human zygote with 45 chromosomes?

Accepted Answer

A)  an error in either egg or sperm meiotic anaphase 
B)  failure of the egg nucleus to be fertilized by the sperm 
C)  failure of an egg to complete meiosis II 
D)  incomplete cytokinesis during spermatogenesis after meiosis I 
A)  an error in either egg or sperm meiotic anaphase 
B)  failure of the egg nucleus to be fertilized by the sperm 
C)  failure of an egg to complete meiosis II 
D)  incomplete cytokinesis during spermatogenesis after meiosis I

Question 2

Turner syndrome is characterized by the presence of only one X chromosome in an affected female. Which of the following accurately describes Turner syndrome?

Accepted Answer

A)  monosomy 
B)  trisomy 
C)  2n + 1 
D)  47,XXX aneuploidy 
A)  monosomy 
B)  trisomy 
C)  2n + 1 
D)  47,XXX aneuploidy

Question 3

What is the most common source of the extra chromosome 21 in an individual with Down syndrome?

Accepted Answer

A)  nondisjunction in the mother 
B)  nondisjunction in the father 
C)  duplication of chromosome 21 
D)  deletion in either parent 
A)  nondisjunction in the mother 
B)  nondisjunction in the father 
C)  duplication of chromosome 21 
D)  deletion in either parent

Question 4

Independent assortment of chromosomes occurs during ________.

Accepted Answer

A)  mitosis only 
B)  meiosis I only 
C)  meiosis II only 
D)  mitosis and meiosis I 
E)  mitosis and meiosis II 
A)  mitosis only 
B)  meiosis I only 
C)  meiosis II only 
D)  mitosis and meiosis I 
E)  mitosis and meiosis II

Question 5

If an organism is diploid and a certain gene found in the organism has 18 known alleles (variants), then any given organism of that species can/must have which of the following?

Accepted Answer

A)  at most, 2 alleles for that gene 
B)  up to 18 chromosomes with that gene 
C)  up to 18 genes for that trait 
D)  a haploid number of 9 chromosomes 
E)  up to, but not more than, 18 different traits 
A)  at most, 2 alleles for that gene 
B)  up to 18 chromosomes with that gene 
C)  up to 18 genes for that trait 
D)  a haploid number of 9 chromosomes 
E)  up to, but not more than, 18 different traits

Question 6

The fastest way for organisms to adapt to a changing environment involves ________.

Accepted Answer

A)  mutation 
B)  asexual reproduction 
C)  sexual reproduction 
A)  mutation 
B)  asexual reproduction 
C)  sexual reproduction

Question 7

Plants produce more seeds when they reproduce asexually than sexually. Yet most plants reproduce sexually in nature. What is the probable explanation for the prevalence of sexual reproduction? Sexual reproduction ________.

Accepted Answer

A)  is more energy efficient than asexual reproduction 
B)  ensures genetic continuity from parents to offspring 
C)  mixes up alleles, contributing to variation in a species 
D)  is not dependent on other agents of pollination 
A)  is more energy efficient than asexual reproduction 
B)  ensures genetic continuity from parents to offspring 
C)  mixes up alleles, contributing to variation in a species 
D)  is not dependent on other agents of pollination

Question 8

In meiosis, homologous chromosomes are separated during ________.

Accepted Answer

A)  anaphase II 
B)  prophase I 
C)  mitosis 
D)  anaphase I 
A)  anaphase II 
B)  prophase I 
C)  mitosis 
D)  anaphase I

Question 9

Which of the following can occur by the process of meiosis but not mitosis?

Accepted Answer

A)  Haploid cells fuse to form diploid cells. 
B)  Haploid cells multiply into more haploid cells. 
C)  Diploid cells form haploid cells. 
D)  A diploid cell combines with a haploid cell. 
A)  Haploid cells fuse to form diploid cells. 
B)  Haploid cells multiply into more haploid cells. 
C)  Diploid cells form haploid cells. 
D)  A diploid cell combines with a haploid cell.

Question 10

The chromosome number of hexaploid wheat, Triticum aestivum, can be represented as ________.

Accepted Answer

A)  n 
B)  2n 
C)  4n 
D)  6n 
A)  n 
B)  2n 
C)  4n 
D)  6n

Question 11

Genetic mutations in asexually reproducing organisms lead to more evolutionary change than do genetic mutations in sexually reproducing ones because ________.

Accepted Answer

A)  asexually reproducing organisms, but not sexually reproducing organisms, pass all mutations on to their offspring 
B)  asexually reproducing organisms devote more time and energy to the process of reproduction than do sexually reproducing organisms 
C)  sexually reproducing organisms can produce more offspring in a given time than can asexually reproducing organisms 
D)  more genetic variation is present in organisms that reproduce asexually than is present in those that reproduce sexually 
E)  asexually reproducing organisms have more dominant genes than organisms that reproduce sexually 
A)  asexually reproducing organisms, but not sexually reproducing organisms, pass all mutations on to their offspring 
B)  asexually reproducing organisms devote more time and energy to the process of reproduction than do sexually reproducing organisms 
C)  sexually reproducing organisms can produce more offspring in a given time than can asexually reproducing organisms 
D)  more genetic variation is present in organisms that reproduce asexually than is present in those that reproduce sexually 
E)  asexually reproducing organisms have more dominant genes than organisms that reproduce sexually

Question 12

The karyotype of one species of primate has 48 chromosomes. In a particular female, cell division goes awry and she produces one of her eggs with an extra chromosome (25). The most probable source of this error would be a mistake in which of the following?

Accepted Answer

A)  mitosis in her ovary 
B)  metaphase I of one meiotic event 
C)  telophase II of one meiotic event 
D)  telophase I of one meiotic event 
E)  either anaphase I or II 
A)  mitosis in her ovary 
B)  metaphase I of one meiotic event 
C)  telophase II of one meiotic event 
D)  telophase I of one meiotic event 
E)  either anaphase I or II

Question 13

The bulldog ant has a diploid number of two chromosomes. Therefore, following meiosis, each daughter cell will have a single chromosome. Diversity in this species may be generated by mutations and ________.

Accepted Answer

A)  crossing over 
B)  independent assortment 
C)  crossing over and independent assortment 
D)  nothing else 
A)  crossing over 
B)  independent assortment 
C)  crossing over and independent assortment 
D)  nothing else

Question 14

Sexual reproduction ________.

Accepted Answer

A)  allows animals to conserve resources and reproduce only during optimal conditions 
B)  can produce diverse phenotypes that may enhance survival of a population in a changing environment 
C)  yields more numerous offspring more rapidly than is possible with asexual reproduction 
D)  enables males and females to remain isolated from each other while rapidly colonizing habitats 
E)  guarantees that both parents will provide care for each offspring 
A)  allows animals to conserve resources and reproduce only during optimal conditions 
B)  can produce diverse phenotypes that may enhance survival of a population in a changing environment 
C)  yields more numerous offspring more rapidly than is possible with asexual reproduction 
D)  enables males and females to remain isolated from each other while rapidly colonizing habitats 
E)  guarantees that both parents will provide care for each offspring

Question 15

Refer to the information and associated figure to answer the following question(s).
-A certain female's number 12 chromosomes both have the blue gene and number 19 chromosomes both have the long gene. As cells in her ovaries undergo meiosis, her resulting eggs (ova) may have which of the following?

Accepted Answer

A)  either two number 12 chromosomes with blue genes or two with orange genes 
B)  either two number 19 chromosomes with long genes or two with short genes 
C)  either one blue or one orange gene in addition to either one long or one short gene 
D)  one chromosome 12 with one blue gene and one chromosome 19 with one long gene 
A)  either two number 12 chromosomes with blue genes or two with orange genes 
B)  either two number 19 chromosomes with long genes or two with short genes 
C)  either one blue or one orange gene in addition to either one long or one short gene 
D)  one chromosome 12 with one blue gene and one chromosome 19 with one long gene

Question 16

Asexual reproduction results in greater reproductive success than does sexual reproduction when ________.

Accepted Answer

A)  pathogens are rapidly diversifying 
B)  a species has accumulated numerous deleterious mutations 
C)  there is some potential for rapid overpopulation 
D)  a species is expanding into diverse geographic settings 
E)  a species is in stable and favorable environments 
A)  pathogens are rapidly diversifying 
B)  a species has accumulated numerous deleterious mutations 
C)  there is some potential for rapid overpopulation 
D)  a species is expanding into diverse geographic settings 
E)  a species is in stable and favorable environments

Question 17

Use the following information to answer the question below.
Trichoplax adhaerens (Tp) is the only living species in the phylum Placozoa. Individuals are about 1 mm wide and only 27 μm high, are irregularly shaped, and consist of a total of about 2000 cells, which are diploid (2n = 12). There are four types of cells, none of which are nerve or muscle cells, and none of which have cell walls. They move using cilia, and any "edge" can lead. Tp feeds on marine microbes, mostly unicellular green algae, by crawling atop the algae and trapping it between its ventral surface and the substrate. Enzymes are then secreted onto the algae, and the resulting nutrients are absorbed. Tp sperm cells have never been observed, nor have embryos past the 64-cell (blastula) stage.
If Tp sperm are observed by future researchers, how many chromosomes should be found in a Tp sperm nucleus?

Accepted Answer

A)  2 
B)  3 
C)  6 
D)  12 
A)  2 
B)  3 
C)  6 
D)  12

Question 18

Centromeres split and sister chromatids migrate to opposite poles in ________ of meiosis.

Accepted Answer

A)  anaphase I 
B)  telophase I 
C)  anaphase II 
D)  telophase II 
A)  anaphase I 
B)  telophase I 
C)  anaphase II 
D)  telophase II

Question 19

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

Accepted Answer

A)  Homologous chromosomes of a pair are separated from each other. 
B)  The chromosome number per cell remains the same. 
C)  Sister chromatids are separated. 
D)  Four daughter cells are formed. 
E)  Cohesins are cleaved at the centromeres. 
A)  Homologous chromosomes of a pair are separated from each other. 
B)  The chromosome number per cell remains the same. 
C)  Sister chromatids are separated. 
D)  Four daughter cells are formed. 
E)  Cohesins are cleaved at the centromeres.

Question 20

Which of the following could be considered an evolutionary advantage of asexual reproduction in plants?

Accepted Answer

A)  increased success of progeny in a stable environment 
B)  increased agricultural productivity in a rapidly changing environment 
C)  maintenance and expansion of a large genome 
D)  production of numerous progeny 
E)  increased ability to adapt to a change in the environment 
A)  increased success of progeny in a stable environment 
B)  increased agricultural productivity in a rapidly changing environment 
C)  maintenance and expansion of a large genome 
D)  production of numerous progeny 
E)  increased ability to adapt to a change in the environment

Exam 13: Meiosis

Which of the following might result in a human zygote with 45 chromosomes?

Turner syndrome is characterized by the presence of only one X chromosome in an affected female. Which of the following accurately describes Turner syndrome?

What is the most common source of the extra chromosome 21 in an individual with Down syndrome?

Independent assortment of chromosomes occurs during ________.

If an organism is diploid and a certain gene found in the organism has 18 known alleles (variants), then any given organism of that species can/must have which of the following?

The fastest way for organisms to adapt to a changing environment involves ________.

Plants produce more seeds when they reproduce asexually than sexually. Yet most plants reproduce sexually in nature. What is the probable explanation for the prevalence of sexual reproduction? Sexual reproduction ________.

In meiosis, homologous chromosomes are separated during ________.

Which of the following can occur by the process of meiosis but not mitosis?

The chromosome number of hexaploid wheat, Triticum aestivum, can be represented as ________.

Genetic mutations in asexually reproducing organisms lead to more evolutionary change than do genetic mutations in sexually reproducing ones because ________.

The karyotype of one species of primate has 48 chromosomes. In a particular female, cell division goes awry and she produces one of her eggs with an extra chromosome (25). The most probable source of this error would be a mistake in which of the following?

The bulldog ant has a diploid number of two chromosomes. Therefore, following meiosis, each daughter cell will have a single chromosome. Diversity in this species may be generated by mutations and ________.

Sexual reproduction ________.

Refer to the information and associated figure to answer the following question(s). -A certain female's number 12 chromosomes both have the blue gene and number 19 chromosomes both have the long gene. As cells in her ovaries undergo meiosis, her resulting eggs (ova) may have which of the following?

Asexual reproduction results in greater reproductive success than does sexual reproduction when ________.

Centromeres split and sister chromatids migrate to opposite poles in ________ of meiosis.

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

Which of the following could be considered an evolutionary advantage of asexual reproduction in plants?

Biology and the Tree of Life

Water and Carbon: the Chemical Basis of Life

Protein Structure and Function

Nucleic Acids and the Rna World

An Introduction to Carbohydrates

Ecosystems and Global Ecology

Lipids, Membranes, and the First Cells

Inside the Cell

Energy and Enzymes: an Introduction to Metabolism

Cellular Respiration and Fermentation

Photosynthesis

Cellcell Interactions

The Cell Cycle

Mendel and the Gene

Dna and the Gene: Synthesis and Repair

How Genes Work

Transcription, Rna Processing, and Translation

Control of Gene Expression in Bacteria

Control of Gene Expression in Eukaryotes

The Molecular Revolution: Biotechnology and Beyond

Genes, Development, and Evolution

Evolution by Natural Selection

Evolutionary Processes

Speciation

Phylogenies and the History of Life

Bacteria and Archaea

Protists

Green Algae and Land Plants

Fungi

An Introduction to Animals

Protostome Animals

Deuterostome Animals

Viruses

Plant Form and Function

Water and Sugar Transport in Plants

Plant Nutrition

Plant Sensory Systems, Signals, and Responses

Plant Reproduction and Development

Animal Form and Function

Water and Electrolyte Balance in Animals

Animal Nutrition

Gas Exchange and Circulation

Animal Nervous Systems

Animal Sensory Systems

Animal Movement

Chemical Signals in Animals

Animal Reproduction and Development

The Immune System in Animals

An Introduction to Ecology

Behavioral Ecology

Population Ecology

Community Ecology

Biodiversity and Conservation Biology

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