Chapter 14

Question 1

Karyotype

Answer 1

A picture of chromosomes arranged together in pairs.

Question 2

When is the karyotype taken?

Answer 2

During mitosis.

Question 3

Sex chromosomes

Answer 3

The two of the 46 chromosomes that determine the sex.

Question 4

Autosomes or Autosomal chromosomes.

Answer 4

The remaining 44 chromosomes (not the sex chromosomes).

Question 5

What do sperm carry?

Answer 5

Half of all sperm carry an X chromosome (23,X) and half carry a Y chromosome (23, Y)

Question 6

What do eggs carry?

Answer 6

All human eggs carry a single X chromosome (23,X)

Question 7

Pedigree Chart`

Answer 7

chart that shows the relationships within a family. Genetic counselors analyze pedigree charts to infer the genotypes of family members.

Question 8

How many genes dopes the human genome have?

Answer 8

It include tens of thousands of genes.

Question 9

What major event happened in 2003?

Answer 9

The DNA of the human genome was published.

Question 10

What are two of the best known blood group genes?

Answer 10

The ABO blood groups and the Rh blood groups.

Question 11

What are many disorders caused by?

Answer 11

They are caused by autosomal recessive alleles.

Question 12

What are some disorders caused by recessive alleles?

Answer 12

They are Albinism, Cystic fibrosis, Galactosemia, Phenylketonuria (PKU), and Tay-Sachs disease.

Question 13

True or false. The dominant allele are not expressed when the recessive allele is present.

Answer 13

False. The effects of a dominant allele are expressed even when the recessive allele is present.

Question 14

What is sickle cell disease caused by?

Answer 14

It is casued by a codiminant allele. It is found in about 1 out of 500 African Americans.

Question 15

What does cystic fibrosis do?

Answer 15

It produces a thick, heavy mucus that clogs their lungs and breathing passageways

Question 16

What does sickle cell disease do?

Answer 16

Hemoglobin is the protein in red blood cells that carries oxygen. In the sickle cell allele, just one DNA base is changed. As a result, the abnormal hemoglobin is less soluble than normal hemoglobin. Low oxygen levels cause some red blood cells to become sickle shaped.

Question 17

What determines sex?

Answer 17

The X chromosome and the Y chromosomes

determine sex.

Question 18

Sex-linked genes

Answer 18

Genes located on the X chromosome and the Y chromosomes

Question 19

What is color blindness associated with?

Answer 19

Three human genes associated with color vision

are located on the X chromosome.

Question 20

True or false: The Y chromosome is
much smaller than the X
chromosome

Answer 20

True

Question 21

nondisjunction

Answer 21

The most common error in meiosis occurs when

homologous chromosomes fail to separate.

Question 22

What happens if nondisjunction occurs?

Answer 22

If nondisjunction occurs, abnormal
numbers of chromosomes may find their
way into gametes, and a disorder of
chromosome numbers may result.

Question 23

How many base pairs in in DNA?

Answer 23

There are roughly 3 billion base pairs in your DNA.

Question 24

DNA fingerprinting

Answer 24

DNA fingerprinting analyzes sections of DNA that
have little or no known function but vary widely
from one individual to another.

Question 25

Where can DNA samples can be obtained from?

Answer 25

DNA samples can be obtained from blood, sperm,

and hair strands with tissue at the base.

Question 26

What happened in 1990?

Answer 26

scientists in the United States and
other countries began the Human Genome
Project.

Question 27

What is the Human Genome Project?

Answer 27

The Human Genome Project is an ongoing
effort to analyze the human DNA
sequence.

Question 28

What happened in June of 2000?

Answer 28

a working copy of the human

genome was essentially complete.