EXAM 3_BI.111-Lindsey

In humans, colorblindness is X-linked and recessive. A male with normal vision and a colorblind female mate. If their child is a girl, what is the chance that she is colorblind?

0%

In a species of coral reef fish, blue fins (B) is dominant to brown red fins (b). Short tails (T) are dominant to long tails (t). What fraction of the progeny of the cross BbTt x BBtt will have blue fins and long tails?

1/2

In humans, Huntington's disease is a rare dominant condition that only appears late in life. If the mother of a child has the disease, what is the probability that her child will have the disease? (that it is a "rare dominant condition" tells you all you need to know to figure out genotypes)

1/2

In humans, there are 3 alleles for blood type: A, B, O. A male with O type blood mates with a female with AB type blood. What is the chance that their child will be heterozygous?

100%

There are red, pink, and white snapdragons, and flower color is controlled by a gene with two alleles: the white allele, and the red allele. The two alleles interact via incomplete dominance. When plants with red flowers are crossed with plants with white flowers, what proportion of the offspring will have pink flowers?

100%

Cytosine makes up 38% of the nucleotides in a sample of DNA from an organism. Approximately what percentage of the nucleotides in this sample will be thymine?

12

Hair color in a certain species of antelope (a DIPLOID) is controlled by a single gene that has 10 different alleles population-wide. A female antelope has hair color that is tan, and her genotype is unknown. How many different types of types gametes - with reference to the hair color gene - could this female antelope generate?

2

Missing questions

2,7,8,12,32,37,44.45

RNA Polymerase works in gene expression by building an RNA transcript while moving along DNA in a __________.

3' 5' direction along the template strand

A particular triplet of bases in the template strand of DNA is 5' AGT 3'. The corresponding codon for the mRNA transcribed is:

3' UCA 5'

Cystic fibrosis (CF) is a Mendelian disorder in the human population that is expressed when the recessive allele is found in the homozygous state. Two normal parents have one child with CF and another normal child. The probability of their next child having the normal phenotype for this characteristic is which of the following?

3/4

Choose the answer that has these events of protein synthesis in the proper sequence. 1. A tRNA bound to a free amino acid binds to the A site. 2. A peptide bond forms between the new amino acid and Methionine. 3. 5' end of the mRNA binds to the small subunit, slides along to AUG. 4. A small ribosomal subunit binds with tRNA for Methionine. 5. The uncharged tRNA translocates from the P site, to exit.

4, 3, 1, 2, 5

Which of the following describes best the arrangement of the constituent parts of an Okazaki fragment?

5' end of fragment has RNA nucleotides, 3' end of fragment has DNA nucleotides

When crossing an individual that is homozygous recessive for a single trait with an individual that is heterozygous for that same gene, what is the chance of producing an offspring with the homozygous recessive phenotype?

50%

A gene codes for a protein that is 500 amino acids long. Which of the following mutations is likely to be the most deleterious?

A nonsense mutation at the fifth codon.

A frameshift mutation could result from

An insertion of 5 consecutive bases

A new DNA strand elongates only in the 5' to 3' direction because

DNA polymerase can only add nucleotides to the free 3' end.

DNA replication is considered semiconservative because

Each daughter DNA molecule consists of one strand from the parent DNA molecule and one new strand.

Once transcribed, eukaryotic mRNA typically undergoes substantial alteration that includes

Excision (cutting out) of introns.

What are the coding segments of a stretch of eukaryotic DNA called?

Exons

Eukaryotic telomeres get shorter after each round of replication. This is a consequence of which of the following?

Gaps left at the 5' end of the lagging strand

Which of the following terms refers to a region of a chromosome that has a specific function?

Gene

A sexually reproducing diploid animal has two genes, one for head shape (H) and one for tail length (T). Its genotype is HhTt. Which of the following genotypes is possible in a gamete from this organism?

HT

What kind of chemical bond is found between paired bases of the DNA double helix?

Hydrogen

What type of bonding is responsible for maintaining the shape of the tRNA molecule?

Hydrogen bonding between base pairs

Chargaff's analysis of the relative base composition of DNA was significant because he was able to show that

In any double-stranded genome, the amount of A is always equivalent to T, and C to G.

Which of the following provides an example of epistasis?

In rabbits and many other mammals, one genotype (cc) prevents any fur color from developing.

What is the effect of a nonsense mutation in a gene?

It introduces a premature stop codon into the mRNA.

Sickle-cell disease is the result of which kind of mutation?

Missense

Which of these statements is true for human sex determination?

Normal females possess two X chromosomes

The F1 offspring of Mendel's classic pea crosses always looked like one of the two parental varieties because

One phenotype was completely dominant over another, and he started with true-breeding strains.

Pea plants were particularly well suited for use in Mendel's breeding experiments for all of the following reasons except that

Peas have an unusually long generation time

Cystic fibrosis is a disease caused by a mutation in a particular gene. This mutation affects the lungs, the pancreas, the digestive system, and other organs, resulting in symptoms ranging from breathing difficulties to recurrent infections. Which of the following terms best describes the action of this gene?

Pleiotropy

Which of the following is a difference between RNA polymerase and DNA polymerase?

RNA polymerase can initiate RNA synthesis, but DNA polymerase requires a primer to initiate DNA synthesis.

Given what you know about the genetic control of phenotypic traits, which of the following headlines from the popular press would have the highest likelihood of being an accurate portrayal of the role of genes in determining a trait?

Scientists isolate a version of a gene associated with obesity.

Mendel's second law of independent assortment has its basis in which of the following events of meiosis I?

Separation of sister chromatids at anaphase

Transcription in eukaryotes requires which of the following in addition to a template section of DNA and an RNA polymerase?

Several transcription factors (TFs)

Two pea plants grown from yellow seeds are crossed, resulting in 600 yellow-seeded offspring and 200 green-seeded offspring. This suggests

That the parents were both heterozygous.

What is meant by the description "antiparallel" regarding the strands that make up DNA?

The 5' to 3' direction of one strand runs counter to the 5' to 3' direction of the other strand.

How similar is the genome in the skin cell of an organism when compared to the genome in a brain cell in the same individual organism?

The sequence of bases in the genome should be the same in all cells of an organism.

Introns are significant to the function of the genome because

Their presence allows exons to be shuffled, creating a much greater diversity of proteins from a single genetic segment.

Using the codon table, what amino acid sequence will be generated, based on the following mRNA codon sequence? 5' AUG-UCU-UCG-UUA-UCC-UUG 3'

met-ser-ser-leu-ser-leu

It was important that Mendel examined not just the F1 generation in his breeding experiments, but the F2 generation as well, because

parental traits that were not observed in the F1 reappeared in the F2.