Question 1

In a life cycle such as that shown in part III of the above figure,if the zygote's chromosome number is 10,which of the following will be true?

Accepted Answer

A) The sporophyte's chromosome number per cell is 10 and the gametophyte's is 5. 
B) The sporophyte's chromosome number per cell is 5 and the gametophyte's is 10. 
C) The sporophyte and gametophyte each have 10 chromosomes per cell. 
D) The sporophyte and gametophyte each have 5 chromosomes per cell. 
E) The sporophyte and gametophyte each have 20 chromosomes per cell. 
A) The sporophyte's chromosome number per cell is 10 and the gametophyte's is 5. 
B) The sporophyte's chromosome number per cell is 5 and the gametophyte's is 10. 
C) The sporophyte and gametophyte each have 10 chromosomes per cell. 
D) The sporophyte and gametophyte each have 5 chromosomes per cell. 
E) The sporophyte and gametophyte each have 20 chromosomes per cell.

Question 2

Which life cycle stage is found in plants but not animals?

Accepted Answer

A) gamete 
B) zygote 
C) multicellular diploid 
D) multicellular haploid 
E) unicellular diploid 
A) gamete 
B) zygote 
C) multicellular diploid 
D) multicellular haploid 
E) unicellular diploid

Question 3

When does the synaptonemal complex disappear?

Accepted Answer

A) late prophase of meiosis I 
B) during fertilization or fusion of gametes 
C) early anaphase of meiosis I 
D) mid-prophase of meiosis II 
E) late metaphase of meiosis II 
A) late prophase of meiosis I 
B) during fertilization or fusion of gametes 
C) early anaphase of meiosis I 
D) mid-prophase of meiosis II 
E) late metaphase of meiosis II

Question 4

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) fertilization of a 23-chromosome human egg by a 22-chromosome sperm of a closely related species 
D) an error in the alignment of chromosomes on the metaphase plate 
E) lack of chiasmata in prophase I 
A) an error in either egg or sperm meiotic anaphase 
B) failure of the egg nucleus to be fertilized by the sperm 
C) fertilization of a 23-chromosome human egg by a 22-chromosome sperm of a closely related species 
D) an error in the alignment of chromosomes on the metaphase plate 
E) lack of chiasmata in prophase I

Question 5

Referring to a plant's sexual life cycle,which of the following terms describes the process that leads directly to the formation of gametes?

Accepted Answer

A) sporophyte meiosis 
B) gametophyte mitosis 
C) gametophyte meiosis 
D) sporophyte mitosis 
E) alternation of generations 
A) sporophyte meiosis 
B) gametophyte mitosis 
C) gametophyte meiosis 
D) sporophyte mitosis 
E) alternation of generations

Question 6

Refer to the life cycles illustrated in the figure below to answer the following questions.
  
-Which of the life cycles is typical for most fungi and some protists?

Accepted Answer

A) I only 
B) II only 
C) III only 
D) I and II 
E) I and III 
A) I only 
B) II only 
C) III only 
D) I and II 
E) I and III

Question 7

To view and analyze human chromosomes in a dividing cell,which of the following is/are required?

Accepted Answer

A) electron microscope 
B) radioactive staining 
C) fluorescent staining 
D) DNA stain and a light microscope 
E) a stain particular to human cells 
A) electron microscope 
B) radioactive staining 
C) fluorescent staining 
D) DNA stain and a light microscope 
E) a stain particular to human cells

Question 8

The following question refers to the essential steps in meiosis described below.
1.Formation of four new nuclei,each with half the chromosomes present in the parental nucleus
2.Alignment of tetrads at the metaphase plate
3.Separation of sister chromatids
4.Separation of the homologues; no uncoupling of the centromere
5.Synapsis; chromosomes moving to the middle of the cell in pairs
-For a species with a haploid number of 23 chromosomes,how many different combinations of maternal and paternal chromosomes are possible for the gametes?

Accepted Answer

A) 23 
B) 46 
C) 460 
D) 920 
E) about 8 million 
A) 23 
B) 46 
C) 460 
D) 920 
E) about 8 million

Question 9

For the following questions,match the key event of meiosis with the stages listed below.
  
-Centromeres of sister chromatids disjoin and chromatids separate.

Accepted Answer

A) II 
B) III 
C) IV 
D) V 
E) VII 
A) II 
B) III 
C) IV 
D) V 
E) VII

Question 10

Which of the following is a true statement about sexual vs.asexual reproduction?

Accepted Answer

A) Asexual reproduction, but not sexual reproduction, is characteristic of plants and fungi. 
B) In sexual reproduction, individuals transmit 50% of their genes to each of their offspring. 
C) In asexual reproduction, offspring are produced by fertilization without meiosis. 
D) Sexual reproduction requires that parents be diploid. 
E) Asexual reproduction produces only haploid offspring. 
A) Asexual reproduction, but not sexual reproduction, is characteristic of plants and fungi. 
B) In sexual reproduction, individuals transmit 50% of their genes to each of their offspring. 
C) In asexual reproduction, offspring are produced by fertilization without meiosis. 
D) Sexual reproduction requires that parents be diploid. 
E) Asexual reproduction produces only haploid offspring.

Question 11

Autosomes are chromosomes,which are

Accepted Answer

A) involved in sexual identity. 
B) capable of reproducing themselves. 
C) involved in the autoimmune responses. 
D) all chromosomes, except sex chromosomes. 
E) the only chromosomes that are inherited. 
A) involved in sexual identity. 
B) capable of reproducing themselves. 
C) involved in the autoimmune responses. 
D) all chromosomes, except sex chromosomes. 
E) the only chromosomes that are inherited.

Question 12

The following question refers to the essential steps in meiosis described below.
1.Formation of four new nuclei,each with half the chromosomes present in the parental nucleus
2.Alignment of tetrads at the metaphase plate
3.Separation of sister chromatids
4.Separation of the homologues; no uncoupling of the centromere
5.Synapsis; chromosomes moving to the middle of the cell in pairs
-Which of the steps takes place in both mitosis and meiosis?

Accepted Answer

A) 2 
B) 3 
C) 5 
D) 2 and 3 only 
E) 2, 3, and 5 
A) 2 
B) 3 
C) 5 
D) 2 and 3 only 
E) 2, 3, and 5

Question 13

If the DNA content of a diploid cell in the G₁ phase of the cell cycle is x,then the DNA content of a single cell at metaphase of meiosis II would be

Accepted Answer

A) 0)25x. 
B) 0)5x. 
C) x) 
D) 2x. 
E) 4x. 
A) 0)25x. 
B) 0)5x. 
C) x) 
D) 2x. 
E) 4x.

Question 14

You have isolated DNA from cells in different stages of meiosis within one species.You have determined the relative DNA content for each type,and plotted the results on the graph shown below.Refer to the graph to answer the following questions.
  
-Which statement best represents the connection between reproduction and evolution?

Accepted Answer

A) Plants that use sexual reproduction are rare since this type of reproduction in plants does not contribute to genetic diversity. 
B) In order to increase genetic diversity for evolution in sexually reproducing organisms, mutations must occur in the zygote after fertilization. 
C) Since prokaryotic organisms reproduce asexually, there is no mechanism for them to add genetic diversity for evolution. 
D) Sexual reproduction increases genetic variation because random mutations can be shuffled between organisms. 
E) The type of reproduction does not impact evolution. 
A) Plants that use sexual reproduction are rare since this type of reproduction in plants does not contribute to genetic diversity. 
B) In order to increase genetic diversity for evolution in sexually reproducing organisms, mutations must occur in the zygote after fertilization. 
C) Since prokaryotic organisms reproduce asexually, there is no mechanism for them to add genetic diversity for evolution. 
D) Sexual reproduction increases genetic variation because random mutations can be shuffled between organisms. 
E) The type of reproduction does not impact evolution.

Question 15

Which of these statements is false?

Accepted Answer

A) In humans, each of the 22 maternal autosomes has a homologous paternal chromosome. 
B) In humans, the 23rd pair, the sex chromosomes, determines whether the person is female (XX)or male (XY). 
C) Single, haploid (n)sets of chromosomes in ovum and sperm unite during fertilization, forming a diploid (2n), single-celled zygote. 
D) At sexual maturity, ovaries and testes produce diploid gametes by meiosis. 
E) Sexual life cycles differ with respect to the relative timing of meiosis and fertilization. 
A) In humans, each of the 22 maternal autosomes has a homologous paternal chromosome. 
B) In humans, the 23rd pair, the sex chromosomes, determines whether the person is female (XX)or male (XY). 
C) Single, haploid (n)sets of chromosomes in ovum and sperm unite during fertilization, forming a diploid (2n), single-celled zygote. 
D) At sexual maturity, ovaries and testes produce diploid gametes by meiosis. 
E) Sexual life cycles differ with respect to the relative timing of meiosis and fertilization.

Question 16

Use the following information to answer the questions below.
A species of lizard has been discovered that reproduces asexually.
-Upon further investigation,there appears to be a few males in the population.This suggests that

Accepted Answer

A) the environment is very stable. 
B) sexual reproduction may occur occasionally. 
C) this is a diploid population. 
D) there are no sex linked chromosomes in the species. 
E) the males must breed with a neighbouring species. 
A) the environment is very stable. 
B) sexual reproduction may occur occasionally. 
C) this is a diploid population. 
D) there are no sex linked chromosomes in the species. 
E) the males must breed with a neighbouring species.

Question 17

To visualize and identify meiotic cells at metaphase with a microscope,what would you look for?

Accepted Answer

A) sister chromatids grouped at the poles 
B) individual chromosomes all at the cell's centre 
C) an uninterrupted spindle array 
D) the synaptonemal complex 
E) tetrads all aligned at the cell's centre 
A) sister chromatids grouped at the poles 
B) individual chromosomes all at the cell's centre 
C) an uninterrupted spindle array 
D) the synaptonemal complex 
E) tetrads all aligned at the cell's centre

Question 18

The diploid number of a roundworm species is 4.Assuming there is no crossover,and there is random segregation of homologues during meiosis,how many different possible combinations of chromosomes might there be in the offspring?

Accepted Answer

A) 2 
B) 4 
C) 8 
D) 16 
E) 64 
A) 2 
B) 4 
C) 8 
D) 16 
E) 64

Question 19

Use the following information to answer the next questions.
There is a group of invertebrate animals called rotifers,among which a particular group of species reproduces,as far as is known,only asexually.These rotifers,however,have survived a long evolutionary history without evidence of having been overcome by excessive mutations.
-How is natural selection related to sexual reproduction as opposed to asexual reproduction?

Accepted Answer

A) Sexual reproduction results in many new gene combinations, some of which will lead to differential reproduction. 
B) Sexual reproduction results in the most appropriate and healthiest balance of two sexes in the population. 
C) Sexual reproduction results in the greatest number of new mutations. 
D) Sexual reproduction allows the greatest number of offspring to be produced. 
E) Sexual reproduction utilizes far less energy than asexual reproduction. 
A) Sexual reproduction results in many new gene combinations, some of which will lead to differential reproduction. 
B) Sexual reproduction results in the most appropriate and healthiest balance of two sexes in the population. 
C) Sexual reproduction results in the greatest number of new mutations. 
D) Sexual reproduction allows the greatest number of offspring to be produced. 
E) Sexual reproduction utilizes far less energy than asexual reproduction.

Question 20

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 which of the following?

Accepted Answer

A) crossing over 
B) independent assortment 
C) crossing over and independent assortment 
D) independent assortment and mutations 
E) mutations, crossing over, and independent assortment 
A) crossing over 
B) independent assortment 
C) crossing over and independent assortment 
D) independent assortment and mutations 
E) mutations, crossing over, and independent assortment

Exam 13: Meiosis and Sexual Life Cycles

In a life cycle such as that shown in part III of the above figure,if the zygote's chromosome number is 10,which of the following will be true?

Which life cycle stage is found in plants but not animals?

When does the synaptonemal complex disappear?

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

Referring to a plant's sexual life cycle,which of the following terms describes the process that leads directly to the formation of gametes?

Refer to the life cycles illustrated in the figure below to answer the following questions. -Which of the life cycles is typical for most fungi and some protists?

To view and analyze human chromosomes in a dividing cell,which of the following is/are required?

For the following questions,match the key event of meiosis with the stages listed below. -Centromeres of sister chromatids disjoin and chromatids separate.

Which of the following is a true statement about sexual vs.asexual reproduction?

Autosomes are chromosomes,which are

If the DNA content of a diploid cell in the G₁ phase of the cell cycle is x,then the DNA content of a single cell at metaphase of meiosis II would be

Which of these statements is false?

Use the following information to answer the questions below. A species of lizard has been discovered that reproduces asexually. -Upon further investigation,there appears to be a few males in the population.This suggests that

To visualize and identify meiotic cells at metaphase with a microscope,what would you look for?

The diploid number of a roundworm species is 4.Assuming there is no crossover,and there is random segregation of homologues during meiosis,how many different possible combinations of chromosomes might there be in the offspring?

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 which of the following?

Introduction: Evolution and Themes of Biology

The Chemical Context of Life

Water and Life

Carbon and the Molecular Diversity of Life

The Structure and Function of Large Biological Molecules

A Tour of the Cell

Membrane Structure and Function

An Introduction to Metabolism

Cellular Respiration and Fermentation

Photosynthesis

Cell Communication

The Cell Cycle

Mendel and the Gene Idea

The Chromosomal Basis of Inheritance

The Molecular Basis of Inheritance

From Gene to Protein

Regulation of Gene Expression

Viruses

DNA Tools and Biotechnology

Genomes and Their Evolution

Descent with Modification: A Darwinian View of Life

The Evolution of Populations

The Origin of Species

The History of Life on Earth

Phylogeny and the Tree of Life

Bacteria and Archaea

Protists

Plant Diversity I: How Plants Colonized Land

Plant Diversity II: The Evolution of Seed Plants

Fungi

An Overview of Animal Diversity

An Introduction to Invertebrates

The Origin and Evolution of Vertebrates

Plant Structure,Growth,and Development

Resource Acquisition and Transport in Vascular Plants

Soil and Plant Nutrition

Angiosperm Reproduction and Biotechnology

Plant Responses to Internal and External Signals

Basic Principles of Animal Form and Function

Animal Nutrition

Circulation and Gas Exchange

The Immune System

Osmoregulation and Excretion

Hormones and the Endocrine System

Animal Reproduction

Animal Development

Neurons,Synapses,and Signalling

Nervous Systems

Sensory and Motor Mechanisms

Animal Behaviour

An Introduction to Ecology and the Biosphere

Population Ecology

Community Ecology

Ecosystems and Restoration Ecology

Conservation Biology and Global Change

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