Biology 121 Exam 2

protein

is made up of hundreds or thousands of smaller units called amino acids, attached to one another in long chains

transcription

RNA is produced from DNA via the process of

this enzyme helps to create mRNA using the information in DNA

RNA polymerase

meiosis ... fertilization

Sexual reproduction requires the cellular process of __________ followed by __________.

Gametes are produced by meiosis.

Which of the following is true about the human life cycle?

a G paired with a T

Which of the following would indicate a base pairing mutation in DNA?

ribsome

serves as the site or protein synthesis in the cytoplasm

CGTCATC

DNA is a double helix composed of nucleotides. Suppose that a portion of one of the two strands of a DNA molecule has the sequence GCAGTAG. What is the sequence of the opposite strand?

DNA directs the production of proteins. DNA produces more of itself.

DNA is considered to be the molecule of life. Which two functions make DNA uniquely suited to this role?

Cancer

an individual with a malignant tumor is said to have

character

an inherited feature that varies from individual to individual

this 3-base subunit on mRNA enables tRNA to deliver the correct amino acid to the growing polypeptide chain

codon

dominant

if an organism has 2 non-identical versions of a gene, the one that is expressed in the organism is called the _____ allele

recessive

if an organism has 2 non-identical versions of a gene, the one that is not expressed in the organism is called the ____ allele

Transcription

is the first step of gene expression, during which a particular segment of DNA is converted into RNA

Translation

is the process in which mRNA codons are converted into an amino acid sequence

this molecule takes information from DNA out to the cytoplasm

mRNA

true

bacteria are the source of plasmids

DNA

serves as the molecular basis for life

interphase

A cell preparing to undergo meiosis duplicates its chromosomes during

RNA

one way that ___ is different from DNA is that it contains U's instead of T's

this molecule has an anticodon that specifies a particular amino acid, which it delivers to the growing polypeptide chain

tRNA

genotype

the _____ is the genetic makeup of an organism

false

the bacterial chromosome is inserted into human cells

false

the bacterial chromosome provides genetic information for making the protein of interest

four haploid cells

A single cell passing through meiosis and cytokinesis results in the formation of __________.

this is the "workbench" where the polypeptide chain is made

Ribosome

replication

DNA copies itself via the process of

can synthesize DNA from an RNA template

A characteristic of the human immunodeficiency virus (HIV) that makes it different from some other RNA viruses is that it __________.

her egg cells

A female that is planning to become pregnant is concerned about her exposure to environmental mutagens which may have caused DNA mutations. In order for these mutations to become heritable, they must affect the:

nondisjunction

Accidents can occur in meiosis wherein members of a chromosome pair fail to separate at anaphase. This is called __________.

cytokinesis

At the end of the mitotic (M) phase, the cytoplasm divides in a process called _________________.

Yes, if both parents are heterozygous for the trait.

Can two plants with purple flowers produce offspring with white flowers?

All flowers will be purple.

Crossing a plant with white flowers and a plant that is homozygous for purple flowers results in offspring with what color combinations?

small

DNA replication occurs at an unbelievably fast rate. Once replication is complete, we can expect to find a _____ number of mistakes.

prophase I.

During meiosis, segments of nonsister chromatids can trade places. This recombination of maternal and paternal genetic material is a key feature of meiosis. During what phase of meiosis does recombination occur?

homologous chromosomes stick together in pairs.

During prophase I of meiosis,

3

Early geneticists wondered how only four nucleotides could specify the sequence of 20 amino acids in proteins. Today we know that there is a genetic code in which __________ nucleotide(s) code(s) for each amino acid.

hey may cause the development of a disease-causing allele they may cause the development of a more beneficial allele they, in some cases, may have no noticeable affect

How do mutations affect an organism?

Her genotype cannot be determined.

Imagine that a deaf male has a child with a hearing female. You know that the male must have the genotype dd, but the female could be either Dd or DD. If the couple's first child has hearing, can you determine the mother's genotype?

male ... the male can contribute either an X or a Y chromosome

In humans, the __________ determines the sex of the offspring because __________.

four haploid cells.

Meiosis starts with a single diploid cell and produces

during cell division daughter cells are genetically identical to the mother cell

New molecules of DNA are synthesized by copying the genetic sequence of another molecule of DNA, which we call the template, so that __________.

translation

Proteins are produced from RNA via the process of

multiple alleles

The ABO blood group in humans is an example of __________ producing four phenotypes.

tRNA ... codon

The anticodon of an incoming __________ molecule, carrying its amino acid, pairs with the mRNA __________ at the ribosome.

Prophase

The centrosomes move away from each other and the nuclear envelope breaks up during which phase of mitosis?

Telophase

The chromosomes arrive at the poles and nuclear envelopes form during which phase of mitosis?

Metaphase

The chromosomes line up in the center of the cell during which phase of mitosis?

prophase I, metaphase I, anaphase I, telophase I, cytokinesis, meiosis II.

The correct order of events during meiosis is

from DNA to RNA to protein

The flow of information in a cell proceeds __________.

the order of the nucleotides in the molecule

The information carried by a DNA molecule is in __________.

cystic fibrosis

The most common lethal genetic disease in the United States is _____.

genetics

The scientific study of the transmission of traits from one generation to the next is called __________.

X and Y

The sex chromosomes in humans that make an individual a male are __________.

Anaphase

The sister chromatids separate and begin moving toward opposite poles of the cell during which phase of mitosis?

Both are composed of nucleotides.

What do DNA and RNA have in common?

They interfere with cell division.

What is the primary characteristic of chemotherapy drugs that causes them to target cancer?

1/2

What is the probability of offspring with the genotype aa when you cross individuals of genotypes Aa and aa?

The chromosomes must be duplicated

What must happen before a cell can begin mitosis?

polygenic inheritance

Which of the following is used to define a phenotypic characteristic resulting from the expression of two or more genes?

XO

Which one of the following combinations of sex chromosomes results in Turner syndrome?

random fertilization crossing over independent orientation of chromosomes in meiosis

Which processes lead to most genetic variation in sexually reproducing organisms?

the gene for hemophilia is sex-linked

Why are human males much more likely than human females to inherit the recessive condition hemophilia (a failure of the blood to clot properly)?

DNA

___ is a long linear polymer found in the nucleus of a cell, shaped like a double helix, an associated with the transmission of genetic information

Malignant Tumor

a ___ is an abnormally growing mass of cells that is actively spreading through the body

Benign Tumor

a ____ is a lump of abnormal cells that, although growing out of control, remains at its original site

monohybrid cross

a genetic cross involving parents that differ in a single character is called a

true

bacteria act as microscopic protein factories

alleles

most human genes come in alternate versions called

trait

one particular variation of a character

phenotype

the physical traits of an organism are called its

RNA

the principal role of ___ is to act as a messenger carrying instructions from DNA out of the nucleus for the synthesis of proteins

Metastasis

the spread of cancer cells from their site of origin to other sites in the body

base

there are 5 examples of a _____: A, G, C, T, and U