exam 3

there is only one offspring who is normal non-carrier. that offspring is

male

different alleles are the result of which

mutations in DNA within a specific gene

which of the following statments about autosomes is true

there are 44 autosomes in humans

1. If a person is a normal non-carrier for the sickle cell trait, then his or her genotype is _______

homozygous

1. If two alleles at a locus on homologous chromosomes are the same, the cell is ______; if the two alleles are different, the cell is _____.

homozygous; heterozygous

what ar the 3 chemical groups that make up a nucleotide

phosphate,deoxyribose, and a nitrogenous base

1. If given the DNA sequence TTACAGCGTACG on one strand of DNA, what would be the base sequence of the other strand?

AATGTCGCATGC

how many children do the parents shown pedigree have

4

if a person has sickle disease then or she is homozygous for the sickle cell allele

true

1. Which of the following labels specifically points to the nucleus of a cell?

1

how many makes in the pedigree have this genetic disease

1

the typical number of chromosomes in a human is

46

1. In poodles, the coat color can be black due to the B allele, which is dominant; or it can be brown due to the recessive b allele.

A. 50% black, 50% brown

A. It is harmful. People with sickle-cell disease die earlier and have severe health problems.

A. It depends. If you live in an area of the world where malaria is very common, it could be considered beneficial but it still causes a very serious disease.

which best describes a gene

A. a segment of DNA that codes for at least one trait

based on the pedigree shown, the disease displayed is carried by a

recessive allele

how many carrier females are shown in the predigree

3

how many males are shown in the pedigree

3

1. Which of the following correctly shows the genotype of the gametes that a person who is a carrier of sickle cell anemia can produce?

HbA or HbS

if a person has sickle cell disease, what is her genotype

HbS HbS

1. Which of the following correctly shows the genotype of the gametes that a person who has sickle cell disease can produce?

HbS only

1. Which of the following is the genetic make-up for a person who is a carrier of the sickle cell trait (heterozygous)?

HbA HbS

1. How many females are shown in the pedigree?

3

1. In the pedigree to the right, how many generations are shown?

2

1. The paternal chromosome that is paired with the maternal chromosome in a homologous pair of chromosomes is shown by which of the following labels?

3

1. An allele of Gene A is shown by which of the following labels?

4

1. If a mom is a carrier and a dad has the sickle cell disease, what is the probability that they will have a child who is a carrier? Use the Punnett square below to help you figure out the answer.

50%

1. In cats, the length of fur is determined by a pair of alleles. The dominant allele L codes for short fur, and the recessive allele l codes for long fur. If a cat had short fur, could you tell by looking at it what its genotype would be?

A. No, if it is showing the dominant phenotype, then its genotype could be LL or Ll.

1. If a person has sickle cell disease, what are the chances that their parents' next child will also have the disease?

A. The chances of having the disease are the same for each child.

1. The figure shown indicates a homologous pair of chromosomes. Which of the following indicates the relationship between Gene A and the circled gene? A.

A. The circled gene must encode information for the same trait as Gene A.

1. What are the bases found in DNA?

A. adenine, thymine, guanine, and cytosine

a genetic disorder is a disorder

A. caused by a genetic mutation that can be inherited by offspring from their parents.

1. Sickle-cell disease is caused by a point mutation in the gene that codes for hemoglobin. In individuals with two copies of the sickle cell allele, their abnormal hemoglobin causes their red blood cells to have a sickle shape. These sickle-shaped red blood cells stick to each other and get caught up in small blood vessels, causing blockages, cell death, and pain. Individuals that have one copy of the sickle cell allele are less likely to die from malaria, an often fatal disease caused by a protist that infects red blood cells. Is the sickle cell allele the result of a beneficial or harmful mutation?

PARAGRAPH

1. Sickle cell disease is an example of a(n) _________ trait in humans.

Variant

A substitution mutation is one where

a single nucleotide

1. You are given the components of a cell in this figure. Based on the figure, the cells shown are _____

diploid

which of the following statements regarding genes is true

genes are the basic unit of information affecting a genetic trait

1. Which of the following statements describes a phenotype?

he has sickle cell disease

1. Consider the three-dimensional structure of DNA shown by label 5. Which of the following has a structure analogous to a molecule of DNA?

spiral staircase

in humans does the egg or the sperm determine the sex of the child

the sperm determines the sex because it contains either an x or a y chromosome

1. In DNA, adenine pairs with _____ and guanine pairs with _____.

thymine cytosine