Biology HW Collection (CH 8-11)

Round seeds (R) are dominant to wrinkled seeds (r), and yellow seeds (Y) are dominant to green seeds (y). What is the expected phenotypic ratio of a cross between an RrYy and an rryy individual?

1:1:1:1

If guanine makes up 30% of the bases in a DNA double helix, what percent of the bases is adenine?

20%

What happens during interphase?

Chromosome duplication occurs.

Which event occurs during anaphase?

Sister chromatids become separate chromosomes.

What is the key to the recognition of incomplete dominance?

The phenotype of the heterozygote falls between the phenotypes of the homozygotes.

Alleles are described as ________.

alternate versions of a gene

In prokaryotes, the production of a single RNA transcript for a group of related genes is under the control of ________.

an operon

Which of these plays a role in the regulation of transcription in both prokaryotic and eukaryotic cells?

attachment of RNA polymerase to the promoter

Chromosomes that do NOT determine the sex of an individual are called ________.

autosomes

A correct comparison between a benign and a malignant tumor is that ________.

benign tumors do not metastasize; malignant tumors do

Which is a type of post-transcriptional regulation of gene expression?

breakdown of proteins

The structure where sister chromatids are joined is called the ________.

centromere

During translation, what is the CORRECT order of events that occur as an amino acid is added to a growing polypeptide chain?

codon recognition, peptide bond formation, translocation

After replication, ________.

each new DNA double helix consists of one old strand and one new strand

The expressed (coding) regions of eukaryotic genes are called ________.

exons

Mendel's law of segregation indicates that

gametes have one allele copy for each gene.

Crossing over during prophase I results in ________.

genetic recombination

Mendel crossed purebred purple-flowered plants with purebred white-flowered plants, and all of the resulting offspring produced purple flowers. The offspring are all ________, and the allele for purple flowers is ________.

heterozygotes; dominant

During metaphase I, ________.

homologous chromosomes line up in the middle of the cell

During anaphase I ________.

homologous chromosomes randomly separate and migrate to opposite poles

A mating between a purebred purple-flowered pea plant and a purebred white-flowered pea plant would produce a(n) ________.

hybrid

The CORRECT sequence of events that occurs during transcription is ________.

initiation, elongation, termination

An individual who is heterozygous for cystic fibrosis ________.

is a carrier

To determine the phenotype of an individual who expresses a dominant trait, you would cross that individual with an individual who ________.

is homozygous recessive for that trait

Linked genes are usually ________.

located close together on a chromosome

What is the specific location of a gene on a chromosome?

locus

Mendel's laws are based on the behavior of chromosomes during ________.

metaphase I and anaphase I of meiosis

Nondisjunction might result in gametes with the chromosome numbers ________.

n + 1 or n − 1

In an operon, the ________ acts as an on/off switch.

operator

Marfan syndrome is the result of inheriting a single allele. Individuals with Marfan syndrome are tall and long-limbed, and have both cardiovascular and eye defects. Marfan syndrome is an example of ________.

pleiotropy

One difference between mitosis and meiosis is that mitosis ________.

produces cells genetically identical to the parent cell, but meiosis does not

The type of cell division that produces two genetically identical daughter cells is important for all of the following functions EXCEPT ________.

production of sperm and eggs

The CORRECT sequence of stages of mitosis is ________.

prophase, metaphase, anaphase, telophase

What type of protein binds to silencers to prevent gene expression from occurring?

repressors

A mutation within a gene that will insert a premature stop codon in mRNA would ________.

result in a shortened polypeptide chain

Which type of reproduction is most adaptive in a rapidly changing environment with many different parasitic diseases present?

sexual reproduction, because the diversity of genotypes increases the likelihood that there is one which can survive in a new environment

How many nucleotides make up a codon?

three

Thymine and cytosine differ from adenine and guanine in that ________.

thymine and cytosine are single-ring structures, whereas adenine and guanine are double-ring structures

Upon completion of telophase I and cytokinesis in meiosis, there is(are) ________ cell(s).

two haploid

The ______ is most commonly found in nature.

wild-type trait

What is the chromosome composition of a normal human male?

44 autosomes, 1 X chromosome, and 1 Y chromosome

Which cross will produce only heterozygous offspring?

AA × aa

During metaphase, ________.

Chromosomes line up in the middle of the cell

What is the first level of control of eukaryotic gene transcription?

DNA packing and unpacking

An individual with the genotype AaBb produces four different gametes in equal proportions. This is a demonstration of ________.

Mendel's law of independent assortment

Red-green colorblindness is inherited as a sex-linked recessive trait. The gene is found on the X chromosome. Can a man with normal color vision father a daughter who is red-green colorblind?

No, he can't (unless there is a mutation).

Which of the following enzymes is responsible for RNA synthesis?

RNA polymerase

What would enable a single RNA transcript to be translated into different polypeptides?

The RNA transcript can be spliced more than one way.

How are the cells in different body tissues able to perform different functions?

The cells exhibit different patterns of gene expression.

What is the key to the recognition of codominance?

The heterozygote expresses the phenotype of both homozygotes.

What happens during prophase?

The mitotic spindle begins to form.

Which outcome could help you identify a trait whose expression is determined by the effects of two or more genes (polygenic inheritance)?

The trait varies along a continuum in the population.

A purebred plant that produces yellow seeds is crossed with a purebred plant that produces green seeds. The seeds of all of the offspring are yellow. Why?

The yellow allele is dominant to the green allele.

What protects mRNA from attack by cellular enzymes?

a cap and tail

An individual who is homozygous ________.

carries two copies of the same allele for a gene

Homologous chromosomes ________.

carry genes controlling the same inherited characteristics

Cells communicate with one another via ________.

signal transduction pathways

A duplicated chromosome consists of two ________.

sister chromatids

Cytokinesis typically begins during the ________ stage of mitosis.

telophase

Homeotic genes are important for ________.

the development of an organism's body plan