Question 1

Match between columns
                        Premises: Animal species X is tetraploid (4 n = 12). Following gene duplication and translocation, a given gene is found on each chromosome. How many alleles for this gene can be present in an individual of this species?
In a dihybrid cross between a parent that is a double heterozygote ( Aa Bb ) and a parent that is a double homozygous recessive ( aa bb ), how many unique phenotypes potentially will be present in their offspring?
Plant species X is diploid (2 n = 24) and has a quantitative trait, the expression of which is controlled by gene loci on each of its chromosomes. What is the maximum number of alleles for this trait that any one individual of species X could have?
In a dihybrid cross between a parent that is a double heterozygote ( Aa Bb ) and a parent that is homozygous dominant for one gene and heterozygous for the other ( AA Bb ), how many unique genotypes potentially will be present in their offspring?
In a dihybrid cross between a parent that is a double heterozygote ( Aa Bb ) and a parent that is homozygous recessive for one gene and heterozygous for the other ( aa Bb ), how many unique phenotypes potentially will be present in their offspring?

Accepted Answer

The Answer of 6 and 4. and 12 and 24 is...

Question 2

The results of a testcross reveal that all offspring resemble the parent being tested. That parent necessarily is

Accepted Answer

A)  heterozygous. 
B)  polygenic. 
C)  homozygous. 
D)  recessive. 
E)  pleiotropic. 
A)  heterozygous. 
B)  polygenic. 
C)  homozygous. 
D)  recessive. 
E)  pleiotropic. C

Question 3

In a Punnett square, the letters within the little boxes represent

Accepted Answer

A)  offspring genotypes. 
B)  parental genotypes. 
C)  gametes. 
D)  offspring phenotypes. 
E)  parental phenotypes. 
A)  offspring genotypes. 
B)  parental genotypes. 
C)  gametes. 
D)  offspring phenotypes. 
E)  parental phenotypes. A

Question 4

In cocker spaniels, black coat color (B) is dominant over red (b) , and solid color (S) is dominant over spotted (s) . If two dihybrids (Bb Ss) were crossed, the most common phenotype would be

Accepted Answer

A)  black and solid. 
B)  black and spotted. 
C)  red and solid. 
D)  red and spotted. 
E)  none of these. 
A)  black and solid. 
B)  black and spotted. 
C)  red and solid. 
D)  red and spotted. 
E)  none of these.

Question 5

Garden Peas In garden peas, one pair of alleles controls the height of the plant and a second pair of alleles controls flower color. The allele for tall ( D ) is dominant to the allele for dwarf ( d ), and the allele for purple ( P ) is dominant to the allele for white ( p ). Use this information to answer the following question(s). In the garden peas example above, a tall plant with purple flowers crossed with a dwarf plant with white flowers produces 1/4 tall purple flowers, 1/4 tall white flowers, 1/4 dwarf purple flowers, and 1/4 dwarf white flowers. What is the genotype of the parents?

Accepted Answer

The answer of Garden Peas In garden peas, one pair...

Question 6

When homologues separate into different gametes after meiosis II, the genes of each pair separate as well. This is the principle of

Accepted Answer

A)  segregation. 
B)  separation. 
C)  colonization. 
D)  variation. 
E)  independent assortment. 
A)  segregation. 
B)  separation. 
C)  colonization. 
D)  variation. 
E)  independent assortment.

Question 7

What fraction of the time will a cross of Aa Bb Cc with Aa BB cc produce an offspring of genotype Aa Bb Cc ?

Accepted Answer

A)  1/32 
B)  1/16 
C)  3/32 
D)  1/8 
E)  none (no chance of this offspring) 
A)  1/32 
B)  1/16 
C)  3/32 
D)  1/8 
E)  none (no chance of this offspring)

Question 8

There are three alleles controlling the blood types ABO. I A and I B are codominant genes, so that the combination I A I B produces the blood type AB. The third allele I O is recessive to the other two alleles. Indicate which of these parents could produce the given child: 
   Parents Child Yes or No 
 (a) A x AB B   
 (b) A x O A   
 (c) A x B O   
 (d) A x AB O   
 (e) A x AB B   
 (f) B x B O   
 (g) AB x AB A

Accepted Answer

(a) yes 
 (b) yes

Question 9

Some dogs have erect ears; others have drooping ears. Some dogs bark when following scent; others are silent. Erect ears and barking are due to dominant alleles located on different chromosomes. If two dihybrids are crossed,

Accepted Answer

A)  the most common phenotype is drooping ears and barking. 
B)  all droopy-eared, silent dogs are pure-breeding. 
C)  the least common phenotype is drooping ears and barking. 
D)  there will be no phenotypes or genotypes that resemble the original parents. 
E)  there will be no offspring that resemble the F 1 generation. 
A)  the most common phenotype is drooping ears and barking. 
B)  all droopy-eared, silent dogs are pure-breeding. 
C)  the least common phenotype is drooping ears and barking. 
D)  there will be no phenotypes or genotypes that resemble the original parents. 
E)  there will be no offspring that resemble the F 1 generation.

Question 10

Skin pigment is made by

Accepted Answer

A)  erythrocytes. 
B)  phagocytes. 
C)  melanocytes. 
D)  dendritic cells. 
E)  fibroblasts. 
A)  erythrocytes. 
B)  phagocytes. 
C)  melanocytes. 
D)  dendritic cells. 
E)  fibroblasts.

Question 11

A parent with the genotype CC will produce which gametes?

Accepted Answer

A)  C and c 
B)  c and c 
C)  C and C 
D)  it will vary with the condition of the parent 
E)  it cannot be determined without more information 
A)  C and c 
B)  c and c 
C)  C and C 
D)  it will vary with the condition of the parent 
E)  it cannot be determined without more information

Question 12

If R is dominant to r , the offspring of the cross of RR with rr will

Accepted Answer

A)  be homozygous. 
B)  display the same phenotype as the RR parent. 
C)  display the same phenotype as the rr parent. 
D)  have the same genotype as the RR parent. 
E)  have the same genotype as the rr parent. 
A)  be homozygous. 
B)  display the same phenotype as the RR parent. 
C)  display the same phenotype as the rr parent. 
D)  have the same genotype as the RR parent. 
E)  have the same genotype as the rr parent.

Question 13

In the cross Cc x Cc , gametes have a ____ chance of receiving either allele.

Accepted Answer

A)  25 - 75 
B)  50 - 50 
C)  75 - 25 
D)  60 - 40 
E)  90 - 10 
A)  25 - 75 
B)  50 - 50 
C)  75 - 25 
D)  60 - 40 
E)  90 - 10

Question 14

A testcross consists of

Accepted Answer

A)  a cross of two pure-breeding forms to find out which form of a gene is dominant. 
B)  a cross between two unknown forms to determine their genotypes. 
C)  a cross between an offspring and its parent. 
D)  a cross of an F 1 hybrid to an individual that is homozygous recessive. 
E)  a cross of two F 2 individuals to produce an F 3 generation. 
A)  a cross of two pure-breeding forms to find out which form of a gene is dominant. 
B)  a cross between two unknown forms to determine their genotypes. 
C)  a cross between an offspring and its parent. 
D)  a cross of an F 1 hybrid to an individual that is homozygous recessive. 
E)  a cross of two F 2 individuals to produce an F 3 generation.

Question 15

When both alleles for a particular trait are expressed at the same time, we see an example of

Accepted Answer

A)  incomplete dominance. 
B)  simple dominance. 
C)  recessivity. 
D)  codominance. 
E)  corecessivity. 
A)  incomplete dominance. 
B)  simple dominance. 
C)  recessivity. 
D)  codominance. 
E)  corecessivity.

Question 16

Traits that are controlled by more than one gene are called

Accepted Answer

A)  codominant. 
B)  pleiotropic. 
C)  polygenic. 
D)  penetrant. 
E)  independent. 
A)  codominant. 
B)  pleiotropic. 
C)  polygenic. 
D)  penetrant. 
E)  independent.

Question 17

The principle of segregation applies most specifically to events occurring in preparation of

Accepted Answer

A)  offspring. 
B)  zygotes. 
C)  homologous chromosomes. 
D)  gametes. 
E)  loci. 
A)  offspring. 
B)  zygotes. 
C)  homologous chromosomes. 
D)  gametes. 
E)  loci.

Question 18

The principle of independent assortment states that

Accepted Answer

A)  one allele is always dominant to another. 
B)  hereditary units from the male and female parents are blended in the offspring. 
C)  the two hereditary units that influence a certain trait segregate during gamete formation. 
D)  each hereditary unit on one chromosome is inherited separately from hereditary units on other chromosomes. 
E)  genes on the same chromosome travel separately. 
A)  one allele is always dominant to another. 
B)  hereditary units from the male and female parents are blended in the offspring. 
C)  the two hereditary units that influence a certain trait segregate during gamete formation. 
D)  each hereditary unit on one chromosome is inherited separately from hereditary units on other chromosomes. 
E)  genes on the same chromosome travel separately.

Question 19

Which is easier to establish in a pure-breeding population, a dominant or a recessive gene?

Accepted Answer

The answer of Which is easier to establish in a...

Question 20

Complex phenotypes that are shaped by more than one gene and also by some aspect of an individual's environment represent a(n)

Accepted Answer

A)  multifactorial trait. 
B)  polygenic trait. 
C)  codominant trait. 
D)  autosomal trait. 
E)  recessive trait. 
A)  multifactorial trait. 
B)  polygenic trait. 
C)  codominant trait. 
D)  autosomal trait. 
E)  recessive trait.

Exam 19: Introduction to Genetics

The results of a testcross reveal that all offspring resemble the parent being tested. That parent necessarily is

In a Punnett square, the letters within the little boxes represent

In cocker spaniels, black coat color (B) is dominant over red (b) , and solid color (S) is dominant over spotted (s) . If two dihybrids (Bb Ss) were crossed, the most common phenotype would be

When homologues separate into different gametes after meiosis II, the genes of each pair separate as well. This is the principle of

What fraction of the time will a cross of Aa Bb Cc with Aa BB cc produce an offspring of genotype Aa Bb Cc ?

Some dogs have erect ears; others have drooping ears. Some dogs bark when following scent; others are silent. Erect ears and barking are due to dominant alleles located on different chromosomes. If two dihybrids are crossed,

Skin pigment is made by

A parent with the genotype CC will produce which gametes?

If R is dominant to r , the offspring of the cross of RR with rr will

In the cross Cc x Cc , gametes have a ____ chance of receiving either allele.

A testcross consists of

When both alleles for a particular trait are expressed at the same time, we see an example of

Traits that are controlled by more than one gene are called

The principle of segregation applies most specifically to events occurring in preparation of

The principle of independent assortment states that

Which is easier to establish in a pure-breeding population, a dominant or a recessive gene?

Complex phenotypes that are shaped by more than one gene and also by some aspect of an individual's environment represent a(n)

Learning About Human Biology

Chemistry of Life

Cells and How They Work

Tissues, Organs, and Organ Systems

The Skeletal System

The Muscular System

Circulation: the Heart and Blood Vessels

Blood

Immunity and Disease

The Respiratory System

Digestion and Nutrition

The Urinary System

The Nervous System

Sensory Systems

The Endocrine System

Reproductive Systems

Development and Aging

Cell Reproduction

Chromosomes and Human Genetics

DNA, Genes, and Biotechnology

Genes and Disease: Cancer

Principles of Evolution

Principles of Ecology

Human Impacts on the Biosphere

Filters