Genetics Exam 3

The enzyme used to separate the DNA double helix during replication is called a what?

Helicase

Which of the following can be used as bacterial cloning vector(s)?

-plasmids

-bacteriophage

What kind of termini is produced by the restriction endonuclease Eco RI, which restriction site has is 5'-G^{}AATTC-3'? (The ^{} represents the site of cleavage in each strand.)

5' overhang

Which of the following vectors is best for accepting DNA fragments ranging up to 5kb (smallest fragment size)?

plasmid

When interpreting the results of microarray at right with DNA samples hybridized to a Black and a White dye, the degree of hybridization between a given probes is measured based on what?

comparing fluorescent intensities between dye types

Based on the picture from question 5. A control/normal sample is labeled with WHITE dye and a cancer sample is labeled with BLACK dye. Which of the samples would most likely represent a Tumor Suppressor Gene?

A4

Which of the following are important components of a high quality plasmid cloning vector?

-known primer sites for amplification

-a multiple cloning site

-having a selection marker to identify host transformation

-having a selection marker to identify insertion of DNA

Which of the following enzymes is essential to produce cDNA?

reverse transcriptase

Why are cDNAs critical to prokaryote production of functional eukaryotic proteins?

cDNA's lack introns so no splicing is required

In normal cell cycle progression from one phase to the next, what general complexes or factors are responsible for regulation of cells into then next cycle phase

Cyclin-CDK complexes

During which of the following cell cycles can development be stopped of arrested?

-G1

-G2

-S

-M

Which of the following characteristics are common to all types of cancers?

uncontrolled proliferation

Mutational events that help with cancer initiation and progression include which of the following

activation of proto-oncogenes

Which of the following occur when p53 is inactivated/losses function?

eliminates the DNA damage checkpoint

Functions of Tumor-suppressor genes include which of the following?

-cellular division

-apoptosis initiation

Loss of chromosome telomeres is associated with what process

senescence

Apoptosis _.

is a normal response to severe DNA damage

The genetic basis for cancer is usually _.

the accumulation of multiple mutations

A population in Hardy-Weinberg proportion is found to have an allele frequency for albinism of 0.09. Given albinism is recessive, what percentage of the population is expected to be albino?

0.81

Phenylketonuria is an inborn error of metabolism caused by autosomal recessive gene. The frequency of this allele in the population is 0.03. Assuming Hardy-Weinberg proportion, what is the expected frequency of phenylketonuria in ospring where both parents are found to be carriers of the disease?

0.25

5000 Vietnamese natives were tested for the MN blood grouping (a bi-allelic alternative blood type). This allele has incomplete dominance and analysis indicated a phenotypic distribution of 600M, 4000MN, 400N. What is the M allele frequency in this population?

5200/10000=0.52

A chicken researcher has identified a new disease that is more common in females than males. Which of the following is(are) reason(s) that explain this finding?

females are hemizygous for this trait

Selection FOR or AGAINST a dominant allele in diploids is ineicient when

the dominant allele is rare

What factor causes the allele frequencies of a gene to shift due SPECIFICALLY to environmental changes?

natural selection

In a population with two alleles, B and b, the frequency of b is 0.6. What proportion of the population would be heterozygotes, assuming Hardy-Weinberg equilibrium?

0.48

The major risk of inbreeding is from the

increased genome frequency of homozygotes

Which of the following processes does not contribute to changing allele frequencies in populations?

Random mating

For a population in Hardy-Weinberg equilibrium the frequency of the homozygous recessive genotype is 0.16. What is the frequency of the recessive allele?

0.4

A trait caused by a recessive X-linked allele in a large, randomly mating population affects 1 male in 1000. What is the frequency of affected females?

1 in 1,000,000

*1000x1000

Which of the following are TRUE about GMO species?

-GMO's have additional genes incorporated into their genomes in one generation

-Long term hybridization among species can produce the same genome as a GMO

Which of the following is a categorical trait

number of ears on a stalk of corn

The variance is

a measure of the spread of the distribution

The genotypic variance of the F1 progeny of a cross between two clonal lines equals (Think Carefully)

0

Traits that are influenced by alleles of two or more genes as well as the environment are termed

quantitative traits

The distribution of height among 1,000 newborn boys has the mean of 50 cm and the variance of 4 cm^{2}. How many boys are expected to be between 46 and 54 cm tall?

950

If the standard deviation of a normal distribution is 3 cm, then what is the variance?

9 cm^2

Which of the following is the best overall description of checkpoints?

checkpoints ensure the integrity of the cell to prevent aberrant replication and growth

Which of the following is(are) sources of genetic variance as they relate to phenotypic variance?

-dominance variation

-epistatic variance

The variance calculated from a distribution of phenotypes equals zero when (Think Carefully)

all individuals have the same phenotype

The ratio of the additive genetic variance to total phenotypic variance is called

narrow-sense heritability

In a cross between two highly inbred (i.e., clonal) lines of Drosophila, the F1 progeny has a phenotypic variance of 0.87 for the number of abdominal bristles. The F2 generation has the phenotypic variance of 3. What is the environmental variance?

0.87

One potential impact of Inbreeding depression is an increase in

rare harmful recessive alleles becoming homozygous

If after several rounds of artificial selection all alleles affecting the trait are fixed or lost, the narrow-sense heritability of a trait is

0

An H^{2} of 0.90 means

ninety percent of the variation in a population is due to genotype differences

What type of selection is seen in the figure to the right?

*bell curve turned wavy curve

disruptive selection

What type of selection pattern is observed in this image?

*bell curve moves left or right on x axis

directional selection

The attached image characterizes which of the following?

environmental effects on phenotypes

You are planning to clone a cDNA isolate into the vector below. Sequence analysis of the cDNA indicates that the restriction enzyme PvuI will cut around the critical sequences and add a complete functional gene. Given this, what antibiotic should be used to isolate bacterial that has taken up the vector WITHOUT killing cells that have taken up DNA?

Tetracycline (tet)

In the attached chart what does the area designated by A represent in terms of each phenotype?

greater genetic effect on phenotype

Which of the following are TRUE about Threshold Quantitative Traits?

threshold traits are often used to define disease conditions