Deck 8: Variation in Chromosome Structure and Number

Question 1

Given the following sequence of genes on a chromosome,determine what change in chromosome structure occurred.The asterisk (*)indicates the centromere.
Before:A B C D * E F G H
After:A B C D * E F E F G H

A) terminal deficiency
B) interstitial deficiency
C) inversion
D) gene duplication

Answer 1

D

Question 2

A translocation cross may occur in an individual which has which of the following?

A) reciprocal translocation
B) unbalanced translocation
C) simple translocations
D) All of these choices are correct.

Answer 2

A

Question 3

Which of following expressions denotes a trisomic organism?

A) 3n
B) 2n-1
C) 2n+1
D) 2n+2

Answer 3

C

Question 4

Examples of euploidy include

A) diploidy.
B) triploidy.
C) tetraploidy.
D) polyploidy.
E) aneuploidy.

Question 5

Inversion loops can occur in which of the following?

A) paracentric inversions
B) pericentric inversions
C) gene duplications
D) reciprocal translocations
E) both paracentric inversions and pericentric inversions

Question 6

The production of gene families,such as the globin genes,is the result of ________.

A) inversions
B) deficiencies
C) gene duplications
D) simple translocations
E) None of these choices are correct.

Question 7

Edward and Patau syndromes are examples of ________.

A) aneuploidy
B) allopolyploidy
C) autopolyploidy
D) translocations

Question 8

Which of the following would have the shortest p arm of the chromosome?

A) acrocentic
B) metacentric
C) telocentric
D) submetacentric

Question 9

The effects of a deficiency on an organism are dependent on the importance of the missing genetic material.

Question 10

Inversions are contained within what percent of the human population?

A) less than 1%
B) approximately 2%
C) approximately 5%
D) greater than 10%

Question 11

Which of the following generally has the least effect on the phenotype of the individual who carries it?

A) Robertsonian translocation
B) unbalanced translocation
C) balanced translocation
D) All of these choices are equally detrimental to the phenotype.

Question 12

Robertsonian translocations usually occur between what types of chromosomes?

A) metacentric
B) acrocentric
C) telocentric
D) submetacentric

Question 13

Given the following sequence of genes on a chromosome,determine what change in chromosome structure occurred.The asterisk (*)indicates the centromere.
Before:A B C D * E F G H
After:A B G F E * D C H

A) reciprocal translocation
B) pericentric inversion
C) paracentric inversion
D) gene duplication
E) None of the answers are correct.

Question 14

What causes gene duplications?

A) the crossing over of misaligned chromosomes
B) deletion of important genetic information
C) reciprocal translocations
D) position effect
E) None of these choices are correct.

Question 15

An inversion heterozygote contains which of the following?

A) two homologous chromosomes with inversions
B) two normal chromosomes
C) one normal chromosome and one chromosome with an inversion
D) None of these choices are correct.

Question 16

What process is the cause of human genetic diseases such a cri-du-chat (or Lejeune)syndrome?

A) translocation
B) duplication
C) deletion
D) inversion

Question 17

Chromosomes may be identified based on which of the following characteristics?

A) location of the centromere
B) banding patterns
C) size of the chromosome
D) All of these choices are correct.

Question 18

Variations in chromosome structure are important for which of the following reason(s)?

A) evolution of new species
B) may result in the production of abnormal offspring
C) may alter the phenotype of an organism
D) All of these choices are correct.

Question 19

A loss of an internal portion of a chromosome is called a(n)________.

A) reciprocal translocation
B) terminal deficiency
C) interstitial deletion
D) gene duplication

Question 20

Given the following sequence of genes on a chromosome,determine what change in chromosome structure occurred.The asterisk (*)indicates the centromere.
Before: A B C D * E F G H
After:A C D * E F G H

A) terminal deletion
B) interstitial deletion
C) inversion
D) gene duplication

Question 21

Due to the formation of an inversion loop,sections of DNA may either be duplicated or deleted.

Question 22

_______ is a drug that is used to experimentally produce polyploidy in organisms.

A) Penicillin
B) Colchicine
C) Polymosca
D) Karyocine

Question 23

The failure of chromosomes to separate during anaphase is called ________.

A) synapsis
B) maternal effect
C) epistasis
D) nondisjunction

Question 24

The short arm of a chromosome is denoted by the letter ________ and the long arm by the letter ________.

A) p; q
B) s; l
C) q; p
D) c; d

Question 25

What are Klinefelter and Turner syndromes examples of?

A) sex chromosome aneuploidy
B) autosomal aneuploidy
C) reciprocal translocations
D) paracentric inversions

Question 26

The polytene chromosomes of Drosophila are an example of ________.

A) aneuploidy
B) polyploidy
C) translocations
D) inversion loops
E) None of these choices are correct.

Question 27

Variations in a gene are called allelic variations.

Question 28

Which type of plant would usually be a seedless variety?

A) aneuploid
B) diploid
C) triploid
D) tetraploid

Question 29

A ________ translocation occurs when a piece of one chromosome is attached to another chromosome.

A) simple
B) complex
C) reciprocal
D) balanced

Question 30

The ends of chromosomes have areas of repeated DNA called centromeres.

Question 31

The majority of autosomal aneuploid conditions are lethal,but sex chromosome aneuploids are usually not lethal.

Question 32

Which of the following describes an organism with two complete sets of chromosomes from two different species?

A) tetraploid
B) aneuploid
C) allodiploid
D) allotetraploid

Question 33

Since no genetic material is lost or gained by an inversion,it will only influence phenotype if the breaks are within a gene or in important regulatory regions for a gene.

Question 34

Which correctly describes mitotic nondisjunction?

A) It is a relatively rare event.
B) It results in the loss of chromosomes in some cells.
C) It usually does not affect all of the cells of the organism.
D) All of these choices are correct.

Question 35

Homologous genes within a species are called paralogs.

Question 36

Select the pairs that correctly match an aneuploid condition to its genotype.

A) Edward syndrome - trisomy 18
B) Down syndrome - trisomy 21
C) Jacobs syndrome - XYY
D) Turner syndrome - XXY
E) Klinefelter - XO 

Question 37

The term ________ refers to genetic differences between members of the same species.

A) chromosomal variation
B) genetic variation
C) chromosomal deletions
D) polyploidy

Question 38

Which human cells exhibit endopolyploidy?

A) sex cells
B) nerve cells
C) all somatic cells
D) liver cells
E) red blood cells

Question 39

Polyploid plants tend to produce less fruits and flowers,be smaller in size,and cannot adapt as well to extreme environmental conditions as normal varieties.

Question 40

Inversions represent a change in the total genetic material of a chromosome.

Question 41

Polytene chromosomes are

A) chromosomes that lack telomeres.
B) chromosomes with high copy number variation.
C) backup copies of chromosomes that are kept segregated away from the functional copies.
D) bundles of hundreds of copies of the same chromosome.

Question 42

If a disease is associated with copy number variation,that suggests that it is caused by the presence of

A) mRNA transcripts missing the translation STOP sequence.
B) a much longer version of a gene.
C) a duplicated or deleted copy of a gene.
D) extra telomeres.

Question 43

Describe endopolyploidy,and how it might benefit an organism.

A) Portions of the organism have extra copies of all chromosomes, for producing additional gene products.
B) The entire organism has extra copies of certain chromosomes, for producing additional gene products.
C) The entire organism has extra copies of all chromosomes, to act as backup in case of DNA damage.
D) Portions of the organism have extra copies of certain genes, for the functions of specialized cell types.

Question 44

Genetic abnormalities that occur after fertilization may result in some tissues of the body differing in their genetic composition.This is called ________.

A) mosaicism
B) polyploidy
C) polypheny
D) genetic variation

Question 45

Visible or measurable characteristics of an organism,resulting from its genotype,are called its ________.