BSC 103 Exam 2

Mutations are __________________.

sometimes harmful, sometimes helpful, and sometimes neutral

Proteins do all of the following tasks EXCEPT ____________________.

store information

The overall three-dimensional shape of a protein is determined by ___________________________.

the order of amino acids and how it folds up

Alleles are alternate versions of _____ gene(s) that have ____ nucleotide sequences.

the same; small differences in their

Metastasis is ____________________________.

the spread of cancer from one location in the body to another

An animal modified by humans to carry genes from another species is called _____________________________.

transgenic

Codominance is when _____________________.

both alleles contribute equally to the phenotype

If someone is said to be "heterozygous" for a trait, it means that ______________________________.

both alleles for that trait are different

Permanent activation or overexpression of proto-oncogenes has been linked to ______________________________.

breast cancer

Cancer consists of too much _____________________.

cell division

During meiosis the _____________________________.

cells divide twice

Somatic cells are _____________________.

cells that do not become reproductive cells

The genetic code table shows the relationship between ___________ and ___________.

codons; amino acids

Translation is a process that occurs in the ____ and uses ___ to produce ____.

cytoplasm; mRNA; proteins

Radiation therapy for cancer works by __________________________.

damaging the cell's DNA, resulting in cell death

An organism's _________ determines its __________.

genotype; phenotype

Independent assortment means ______________________________.

homologous chromosomes segregate into daughter cells randomly and independently of one another

Which term would represent the trait cystic fibrosis?

homozygous recessive

Hair texture is a result of _____________________.

incomplete dominance

You cross a red flower with a white flower, and all the seeds result in pink flowers. This is an example of _________________________.

incomplete dominance

What is NOT a known source of mutations?

insufficient sleep and poor diet

A cell spends most of its time in ____________________.

interphase

The function of a protein does NOT depend on ________________________.

its gene's regulatory sequence

In_________, chromosomes align in the middle of the cell, tugged there by spindle fibers.

metaphase

Up to 40% of human height can be attributed to environmental rather than genetic factors; thus, we call height inheritance____________________________.

multifactorial

Aneuploidy is the result of ________________________.

nondisjunction

DNA replication occurs in the __________________.

nucleus

Transcription occurs in a eukaryotic cell's ____, and it uses ____ to produce _____.

nucleus; genes; mRNA

In humans, a homologous chromosome pair consists of ___________________________.

one chromosome from mom and one from dad

In humans, after meiosis, one diploid cell produces _________________________.

our unique haploid daughter cells

Chromosomes first coil up and become visible during _______________________.

prophase

The correct order of phases in mitosis is ____________________, ___________________, ____________________, and ________________________.

prophase, metaphase, anaphase, and telophase

Which of the following occurs during interphase?

replication of chromosomes

Cell division is usually kept under control by _________________________________.

several checkpoints in the cell cycle and by apoptosis

True or False: All members of the population should be genetically tested for hereditary cancers.

False

True or False: Genetically modified organisms have been unequivocally to be detrimental to human health.

False

True or False: If genetic testing reveals you carry a certain mutation that has been linked to cancer, then you are sure to develop cancer.

False

True or False: In genetics, a recessive allele is designated by an upper-case letter (A).

False

True or False: Mitosis is required to halve the chromosome number of cells.

False

True or False: One mutation in a tumor-suppressor gene or a proto-oncogene is sufficient to cause cancer.

False

True or False: Punnett squares cannot be used to track the inheritance of two genes.

False

True or False: Recessive alleles are never transcribed and therefore never produce protein.

False

What RNA molecule would be made from the DNA template CGTTACG?

GCATTGC

An individual's DNA is ____________________.

Identical in all cells

What does RNA polymerase do?

It binds to the regulatory sequence of DNA and produces mRNA.

Why can you say that males determine the sex of their children?

Males will either contribute an X or a Y chromosome, whereas females will always contribute an X chromosome.

The sex chromosomes found in a typical male are ______________________.

XY

If we drew a graph for a trait exhibiting polygenic inheritance, the graph would be _________________________________.

a bell curve

Stage 0 of caner is _________________.

A cell that becomes a cancer cell usually does so in the company of other similar cells. Often, but not always, it can produce a tumor right there in that tissue, in a way that poses little or no threat to life.

What is a chromosome?

A large, tightly bound piece of DNA and protein found in the nucleus of cells.

What is a gene?

A segment of DNA that encodes at least one protein.

If a DNA coding region has 12 nucleotides, how many amino acids could it encode?

4

A heart muscle cell of a person with Down syndrome has _____ chromosomes.

47

______ is/are made of ______, and ______ contain(s) many ______.

1. Chromosomes; DNA; chromosomes; genes. 2. Genes; DNA; chromosomes; gene.

Why are X-linked traits more commonly expressed in males?

1. There is no masking of an affected X allele with a normal X in males. 2. Females must have two copies of the affected allele to display a phenotype. 3.Females may be unknowing carriers and pass on the trait to male progeny. 4. Males only have one X chromosome.

What is an example of a mutation in an allele?

1. a base change in the gene coding sequence 2. a base change in the gene's regulatory regions 3. a deletion of a base within the gene 4. an insertion of a base within the gene

In normal cells, lack of functional tumor suppressors would cause _____________________.

1. an accumulation of mutations in the DNA. 2. division of damaged cells. 3. cancer, possibly. 4. uncontrolled cell division.

The process of DNA replication requires ____________________.

1. breaking hydrogen bonds 2. unwinding of the DNA 3. enzymes 4. nucleotides

________________ helps to prevent cancer.

1. cell cycle checkpoints 2. apoptosis 3. DNA repair enzymes 4. regulation of the cell cycle

The regulatory sequence of a gene is the portion of DNA that __________________________.

1. determines when a protein is made 2. can "turn on" or "turn off" a gene 3. determines how much of a protein is made 4. determines in which cells a gene is expressed

Two normal individuals have a child who has cystic fibrosis, an autosomal recessive disease. What were the chances of this happening?

1:4 chance

How many copies of any particular gene does an individual human have?

2

How many chromosomes do human sperm and egg cells have?

23

Humans have _____________________.

23 pairs of chromosomes, which include the sex chromosomes

What is DNA polymerase?

An enzyme involved in DNA replication that binds to DNA and facilitates the formation of a new strand of DNA

What causes cancer to kill people?

Cancer cells crowd out normal cells and disrupt organ functions.

Stage 1 of caner is _________________.

Cancer cells gain the ability to pass through the basement membrane and to invade neighboring tissue. This indicates that the growing cancer cells may threaten life.

Stage 2/3 of caner is _________________.

Cancer cells travel lymph vessels and form a tumor in the closest lymph nodes.

Stage 4 of caner is _________________.

Cells from tumor in the lymph node spread further through lymph vessels to more distant lymph nodes or on into the blood stream to there areas of the body.

Which of the following is NOT needed for gene expression?

DNA polymerse

PCR amplification of DNA requires ______________, __________________, _________________, and ____________________.

DNA, primers, DNA polymerase, and deoxyribonucleotides

What is meant by "semiconservative" replication?

Each newly replicated strand of DNA consists of one original strand and one newly formed strand.

Why aren't all mutations that occur in DNA inherited by our offspring?

Only mutations in the DNA contained in the sperm and eggs will be inherited.

PCR stands for ____________________.

Polymerase Chain Reaction

How is genetic diversity created in meiosis I?

Recombination of sister chromatids occurs in meiosis I.

What is the significance of STRs in DNA profiling?

STRs vary in length from person to person, which helps to identify specific individuals.

STR's are ______________________.

Short Tandem Repeats

You have a segment of DNA with a nucleotide sequence reading AATAGC on one strand. Which of the following nucleotide sequences would match it on the opposite strand?

TTATCG

DNA can be visualized as a ladder. Which parts would be the rungs (where you step) and which would be the stringers (the sides where you hold on)?

The bases are rungs, and the sugars and phosphates are stringers.

Two healthy individuals have a child who has Huntington disease, an autosomal dominant disease. How did this happen?

This is implausible -- the condition could not have been inherited from these two parents.

What is a codon?

Three mRNA nucleotides that encode a specific amino acid.

True or False: A pedigree chart is used to examine inheritance over generations.

True

True or False: Alleles are just different versions of the same gene.

True

True or False: Cancerous cells are capable of evading the immune response through numerous mechanisms.

True

True or False: Gene therapy shows promise for people with severe combined immunodeficiency (SCID).

True

True or False: Huntington disease is caused by a dominant allele.

True

True or False: Round-up ready corn carries a gene which makes it resistant to this herbicide.

True

True or False: The genetic code is redundant.

True

True or False: The genetic code is universal for nearly all organisms.

True

True or False: The severity of cystic fibrosis is influenced by other genes, for example TGFβ1.

True

True or False: tRNA bears the anti-codon, which is complementary to the codon of the mRNA.

True

What are the four nucleotide bases that make up the "rungs" of the nucleotide ladder of DNA?

adenine, thymine, guanine, cytosine

Chemotherapeutics act on _______________________.

all dividing cells

An allele is _________________.

an alternate version of a gene

XXX, XO, XYY, and XXY conditions are the result of __________________________.

an error during meiosis

The correct amino acid is selected and added to the growing protein, when the ______ and ____ bond to each other.

anticodon; codon

If a cell is irreparably damaged, it undergoes programmed cell death, called ___________________________.

apoptosis

The end result of mitosis and cytokinesis is _____________________.

two cells identical in size and genetic material.

DNA replication results in __________ copies of a cell's genome.

two identical

An example of a codominant trait is ________________________.

type AB blood