Biology 1 Exam 2: Chapter 8-12

Nondisjunction of the sex chromosome sometimes becomes unlinked because of

Crossing-over

A chromosomes gene sequence that was ABCDEFG before damage and ABCFG after is an example of

Deletion

The use of RFLP's for "genetic fingerprinting" is based on

Differences of locations where enzymes make their cuts

Which term refers to the processes by which cells with identical genotypes become structurally and functionally distinct from one another

Differentiation

If height in humans is controlled by three pairs of alleles, how tall, comparatively speaking, would AaBbCc most likely be?

Intermediate

Skin color is believed to be regulated by alleles A, B, and C. What color is a person with AaBbCc genotype?

Intermediate

The portion of the DNA molecule that is not translated and is a noncoding portion of DNA is composed of

Introns

A chromosomes gene sequence that is ABCDEFG before damage and ABFEDCG after is an example of

Inversion

Which statement is true regarding the Barr body?

It is found in the nuclei of females.

If individuals have XXY genotypes, they are classified as having

Klinefelter syyndrome

This is the substrate broken down by the product of this gene

Lactose

The DNA molecule could be compared to a

Ladder

The difference between normal hemoglobin and sickle-cell hemoglobin is in the

substitution of a specific amino acid for anoteh specific amino acid

Which of the following carries amino acids to ribosomes, where amino acids are linked into the primary structure of a polypeptide?

tRNA

Ribosomes function as

two-part units

James Watson and Francis Crick

explained how DNA's structure permitted it to be replicated

During the cell cycle, a cell

grows and then divides

Down syndrome

is known as trisomy 21

Mitosis differs from meiosis in that, in meiosis

it occurs only in the reproductive organs

Crossing-over occurs during

meiosis I

Variation is usually introduced by the process of

meiosis and crossing-over

Synthesis of DNA

occurs during interphase

Transcription

occurs during the synthesis of any type of RNA from a DNA template

A basic difference between spermatogenesis and oogenesis is that in oogenesis

only one cell eventually completes meiosis II

If the total number of chromosomes in a cell is 6, then after mitosis there will be

6 chromosomes in each daughter cell

There are how many different kinds of RNA codons?

64

Which sequence of the cell cycle is correct?

Telophase, interphase, prophase, metaphase

A person with Turner's syndrome is

produced by nondisjunction of an X chromosome

Replication of DNA

produces two molecules, each of which is half-new and half-old DNA joined lengthwise to each other.

Linkage

refers to the tendency of genes found on the same chromosome to be inherited together

The genetic code is made up of units consisting of how many nucleotides?

3

The RNA molecule is made up of how many strands?

1

A family has seven sons. The chance that their eight child will be a daughter is

1/2

The DNA molecule is usually made up of how many strands?

2

In humans, in red hair is recessive to dark hair. What are the chances of a dark-haired couple having a red-haired child if they each had a red-haired parent?

25%

If a father has type B blood (one of his parents was type O) and the mother has type AB, what type might their child have?

A, B, AB

The nitogenous base found in DNA but not RNA is

Adenine

Uracil will pair with

Adenine

The reason that sexually reproducing organisms produce offspring that are different from themselves is

All of these-- crossing over; the random arrangement of chromosomes at the spindle equator; fertilization is a chance mix of genetically different gametes.

DNA polymerase

All of these-- is an enzyme; adds new nucleotides to a strand; proofreads DNA strands to see that they are correct; derives energy from ATP for synthesis of DNA strands

Mutations can be

All of these-- random; beneficial; harmful; heritable

Alternative forms of a gene that influence the same trait and are found at the same location in homologous chromosomes are called

Alleles

During _____, daughter chromosomes are widely separated having moved two-thirds the distance from the equatorial plate.

Anaphase

In humans, brown eyes are dominant over blue eyes. A brown-eyed woman, who has a blue-eyed child, has the genotype

Bb

In Mendel's time, the conventional wisdom stated that

Characteristics of the parents blended together in the offspring

In most sexually reproducing organisms, the body cells of the adult are

Diploid

The portion of the DNA molecule that is translated is composed of

Exons

T or F: Cancer cells, in contrast to normal cells, have a limited number of times they can divide.

False

T or F: Cell division in prokaryotes does not involve mitosis.

False

T or F: In humans, there are 14 pairs of chromosomes.

False

T or F: Only genes that relate to the sex of the individual will be found on the sex chromosomes.

False

The discoverer of the laws of genetics was

Gregor Mendel

In the bonding of nitrogenous bases

Guanine is paired with cytosine

In cattle, the lack of horns is dominant to the presence of horns. A bull without horns is crossed with a horned cow. Of the four offspring, one is horned and the other three lack horns. The bull is

Heterozygous

The carriers of a sex-linked trait are ____ that do not express the recessive trait they carry

Heterozygous males

Chromosomes are strands of DNA wound around proteins called

Histones

What is the form of RNA that carries the code from the DNA to the site where the protein is assembled?

Messenger RNA

When a gene transcription occurs, which of the following is produced?

Messenger RNA

In mitosis, what stage shows chromosomes at the equator?

Metaphase

The spread of cancer from one site to others in the body is known as

Metastasis

Blood types are controlled by

Multiple alleles

If a woman has type AB and has a child with type AB, to which blood type could the father not belong?

O

Mr. X has been accused by Miss. Z of fathering her child. The child's blood type is AB, Miss. Z's blood type is A. Mr. X could not be the father if his blood type is

O

A repressor protein can shut down transciption by binding to this item

Operator

This item contains regulator, promoter, and operator regions

Operon

Mendel carried most of his research with

Pea plants

Which of the following is represented by word descriptions, such as black and tall?

Phenotype only

When compared to asexual reproduction, sexual reproduction

Produces more variety in the offspring

When the repressor is inactivated, RNA polymerase can bind to this item and allow transcriptase to occur

Promoter?

This item codes for the production of repressor

Regulator gene

Enzymes used to cut DNA molecules in recombinant DNA research are

Restriction enzymes

RNA manufacture DNA via the action of

Reverse transcriptase

The two parts of a duplicated chromosome are called _____ chromatids.

Sister

The formation of sperm gametes is termed

Spermatogenesis

If 25% of the offspring show the recessive phenotype, the parents were probably

both hybrid

Which of the following is not true of sex-influenced traits?

They often skip a generation

The specific name given to a cancer-producing chemical is

carcinogen

The synthesis of an RNA molecule from a DNA template strand is

Transcription

T or F: Color blindness occurs most often in men.

True

T or F: Mitosis technically refers only to nuclear division and not cytoplasmic division.

True

If the DNA triplets were ATG-CGT, the mRNA codons would be

UAC-GCA

The sex chromosomes in humans are referred by

X and Y

A color-blind (recessive trait) woman will pass the allele to

all her children

Mendel's law of segregation implies that the two members of an allele pair

are distributed to separate gametes