Bio Test 2 reference

Genetically modified organisms may contain proteins, DNA, and ________ from another organism.

RNA

Gene therapy is described in the Biology in the News article as creating "microscopic factories" that produce missing enzymes or proteins. What provides the instructions to these microscopic factories?

a gene introduced to the patient's body in a recombinant virus

Inheritance of ABO blood type in humans is an example of

a gene that is coded by more than two alleles.

In the genetic code, an amino acid is specified by

a sequence of three mRNA bases.

During transcription

a template strand of DNA directs the production of an mRNA molecule.

An allele is

a version of a gene

Alternate versions of the same gene, such as blue or brown for eye color, are known as ________.

alleles

An enzyme that catalyzes the formation of covalent bonds between two DNA fragments, creating a single piece of DNA, is a(n) ________.

ligase

Each tRNA molecule can bind with up to three codons, but carries only one specific ________.

amino acid

The "rungs" in the DNA "ladder" consist of ________ pairs.

base

Inheritance of ABO blood type in humans is an example of

complete dominance of one allele over another.

In research, restriction enzymes are used to

cut DNA molecules into pieces that can be used to create recombinant DNA.

When compared, the nucleotide sequences of different individuals are________.

different

The allele responsible for causing Huntington disease is

dominant

The chemical structure of bisphenol A (BPA) resembles

estrogen

A mistake during which of the following processes would have the most long-lasting effects on an organism and its offspring?

replication in germ line cells

Suppose D were dominant and d were recessive, and you could label the D allele in the P generation with a radioactive substance that could be inherited over several generations. You create hybrids by mating your radioactive DD individuals to dd individuals. Finally, you cross two Dd individuals. In 1,000 offspring, how many do you predict would be radioactive?

750

Bacteria and humans use the same DNA components, and both kinds of cells also perform transcription and translation. Which of the following choices is a potentially significant outcome of this shared mechanism?

Bacteria are able to transcribe and translate human DNA; thus, they potentially could produce human proteins.

A parent who is a carrier for the recessive autosomal disorder B has the genotype ________.

Bb

Environmental factors can alter the effects of genes.

True

Temperature can affect phenotype.

True

The position of the start codon is important because every molecule of mRNA can be read by a ribosome in three different ways.

True

The bases present in an RNA molecule are

U, A, C, and G.

DNA consists of two twisted strands of ________.

nucleotides

During translation

one mRNA molecule works with several rRNA molecules and many tRNA molecules to produce a protein

Even though it is deadly, the Huntington disease allele can remain in the population, because

people with the disorder often live long enough to reproduce.

A(n) ________ is a small, circular portion of DNA that is found in bacteria and is NOT part of the main genome.

plasmid

As transcription begins, RNA polymerase binds to a segment of a gene called a(n)

promoter

The base sequence of mRNA specifies the sequence of amino acids in a ________.

protein

When examining the two complementary strands of nucleotides in one DNA molecule, you would expect to find that

the sum of Gs and Cs in one strand would be equal to the sum of the Gs and Cs in the other strand.

DNA replication involves the copying of the entire chromosome; in contrast, just a small portion of a chromosome is copied in the process of ________.

transcription

When the breast cancer genes, BRCA1 and BRCA2, are mutated, damaged DNA in the cell is not corrected. Based on this information, the BRCA genes produce ________ proteins.

DNA repair

A rapidly dividing cell is exposed to a chemical that converts the bond that forms between adenine and thymine to a covalent bond. Which of the following is most likely to occur?

DNA replication would not occur because the two nucleotide strands that make up the DNA molecule would not be able to separate.

A genotype is always expressed in the phenotype.

False

At any given time, most of the genes in the genome of an organism are actively undergoing gene expression.

False

DNA fingerprinting can prove guilt without fail.

False

DNA from one organism will not bond to DNA from another organism.

False

Each time transcription occurs, all the DNA in a cell is copied.

False

Experiments involving small numbers of offspring give more reliable results than experiments observing large numbers of offspring.

False

In tRNA, an amino acid is covalently bonded to an anticodon.

False

The gene that, when mutated, causes the white tiger phenotype encodes a transporter for the amino acid methionine that is found in the plasma membrane of melanocytes.

False

The DNA for the normal hemoglobin allele and the mutant sickle-cell allele are cut with the same restriction enzyme, DdeI. The resulting DNA fragments are separated by gel electrophoresis, producing the gel shown in the following figure. Why are the patterns produced by these two alleles different?

The gene for the normal allele has a sequence recognized by DdeI, but the gene for sickle-cell anemia does not.

A genetic cross in which the heterozygous phenotype is intermediate between the two homozygous phenotypes is an example of ________.

incomplete dominance

Human gene therapy involves

introducing a functioning copy of the defective gene into the patient.

The sequence of nucleotides in an mRNA molecule

is complementary to the DNA template strand.

A potential danger of a mutation to an organism is that

it can cause a change in the function of a gene's protein product.

When the wrong base is inserted during DNA replication, a(n) ________ error occurs.

mismatch

A mutation that occurs in a diploid cell can be inherited only if the

mutation occurs in a cell that produces gametes.

A man is a carrier for a recessive disease allele. A woman is not a carrier and does not have the disease. The couple has four children and

none of the children have the disease.

Cloned animals are genetically identical to the

somatic cell donor