Rutgers Biology 115 Exam 2 Review

These flashcards cover key concepts, processes, and definitions from the Rutgers Biology 115 Exam 2 Review material.

What chromosome number do cells A and B have in the image?

Cell A has 6 chromosomes and cell B has 6 chromosomes.

How many chromosomes are present in a white-tailed deer kidney cell during interphase and mitotic phase?

There are 70 chromosomes in the cell during interphase and 70 chromosomes in the cell during the mitotic phase.

What is the immediate outcome if a cell in M phase is exposed to a toxin preventing DNA separation?

The sister chromatids will not move to opposite poles.

In the image referred to in Q#4, what is Y and Z respectively?

Y is a chromosome and Z is a sister chromatid.

What is the ploidy of daughter cells after a diploid cell with 34 chromosomes undergoes mitosis?

2n=34.

What is the correct sequence of events that occur starting with the S phase?

DNA is replicated, chromosomes condense, mitotic spindle fibers attach to the kinetochores, sister chromatids move to opposite sides of the cell, and finally, the nuclear envelope reforms.

In which stages of mitosis and meiosis do sister chromatids separate?

Sister chromatids separate during Anaphase of both mitosis (I) and meiosis (III).

What stage of the cell cycle are cells in if they show high levels of helicase and SSBP?

The cells are currently in interphase.

Which processes occur in the lifecycle of both a fungus and an animal?

Fertilization, mitosis, meiosis, 2n cells, and haploid cells.

During which phase of meiosis is ploidy reduced?

Ploidy is reduced during the first meiotic division.

How many chromosomes do Aedes aegypti males have during prophase I and prophase II of meiosis?

They have 6 chromosomes during prophase I and 3 chromosomes during prophase II.

What is the ploidy and chromosome count for the plant cell in metaphase II if it has a ploidy of 20n?

The ploidy is 10n and the number of chromosomes is 1000.

In what stage are cells haploid during meiosis?

Cells are haploid in interkinesis.

What is a benefit of asexual reproduction?

Only a single parent is required.

Which image depicts a cell in Metaphase II?

Image III shows a cell in Metaphase II.

Which statements are true regarding the provided Punnet Square?

This is a monohybrid cross and both parents are heterozygous.

What are the true statements regarding alleles?

They are sequences of DNA, segregated into different gametes, and are versions of a gene.

Which term describes an individual with two different alleles for a gene?

Heterozygous.

What observations by Mendel invalidated the blending inheritance hypothesis?

F1 was comprised entirely of a single parental phenotype and F2 contained parental phenotypes that were absent in F1.

What genotype represents a test cross with a dog that is a carrier for deafness?

Hh x hh.

What is true of dominant alleles?

Dominant alleles will mask the presence of recessive alleles.

How is the combined probability of two independent events determined?

It is determined by multiplying their separate probabilities.

In which situations is it appropriate to use the addition rule?

Determining the combined probability of mutually exclusive events and events that cannot occur simultaneously.

Which of the following is NOT a reason that fruit flies made a good test organism?

They have many chromosomes.

What type of inheritance pattern could a trait have if neither parent expresses the trait and a quarter of the offspring express it?

Mendelian inheritance.

What is the probability of a male offspring not having a recessive X-linked trait from a female carrier?

0.25.

What does it mean for an organism with sex chromosomes XY to be hemizygous?

Every allele on the X chromosome is expressed.

Which statements are true for male and female cockatiels concerning Z-linked diseases?

Z-linked diseases are more commonly expressed in female cockatiels, and female cockatiels are heterogametic.

What was Thomas Morgan's central finding that differed from Mendel's conclusions?

Genes move on chromosomes, not as individual units.

If a man inherits an X-linked disorder, who could be the source of that disorder?

Maternal grandmother or maternal grandfather.

What are Barr bodies?

They occur when one X chromosome is randomly deactivated.

Which end of a DNA molecule is referred to as the 5' end?

The 5' end of the molecule is at the top right.

What sequence correctly follows the proteins involved in DNA replication?

Helicase, single-strand binding proteins, primase, DNA polymerase.

What is the reverse complement of a DNA strand 3' A A T G G C T A C 5'?

5' T T A C C G A T G 3'.

What components are part of a cytosine nucleotide?

A pyrimidine, a five-carbon sugar, and a phosphate group.

How does DNA polymerase I operate?

It catalyzes the formation of phosphodiester bonds and synthesizes a complementary daughter to the parent strand.

What happens if RNA primase cannot function during replication?

DNA polymerase would be unable to place the first DNA nucleotide.

Where would the DNA molecule be affected by breaking hydrogen bonds?

Between a pyrimidine and a purine.

What statements are true about nucleotides?

They will pair with a pyrimidine, are made of adenine or guanine, and are found in prokaryotes and eukaryotes.

What is the correct sequence of eukaryotic gene expression events?

RNA polymerase attaches to promoter, transcript is elongated, mRNA receives a poly A tail, mRNA leaves the nucleus, and start codon triggers translation.

What describes transcription?

DNA is used as a template to generate specific mRNA.

Which action occurs only in eukaryotes?

Placement of a 5' cap on pre-mRNA.

Which processes depend on base pairing?

Transcription, translation, and DNA replication.

What is the function of aminoacyl-tRNA synthetase?

To covalently link an amino acid to a tRNA.

What are the predicted effects of cycloheximide treatment on translation?

Translation elongation will not occur normally, and peptide bond formation will be inhibited.

Where does the repressor protein bind on a prokaryotic operon?

At the operator.

What would happen if an inducer cannot bind to the repressor?

The operon would never be expressed.

What is the correct sequence for translation?

Small ribosomal subunit binds with mRNA, initiator tRNA base-pairs with the start codon, large ribosomal subunit joins the initiation complex, peptide bond formation occurs, and release factors bind to the codon in the A site.

Which processes occur in both prokaryotic and eukaryotic cells?

Translation, replication, and transcription.

What happens if a mutation prevents DNA methylation?

More frequent transcription.

What does a rise in CAP in E. coli indicate?

Very little glucose is available and cAMP levels are rising.

What would be true for an E. coli cell in a medium of high glucose and high lactose?

Low cAMP levels and low level of LAC transcription.

What is an example of positive regulation of an operon?

CAP helps RNA polymerase attach to the promoter.

What is the sequence of steps in DNA dideoxy sequencing?

DNA fragment is denatured, primer and necessary components are added, strand elongation occurs, single strands are loaded onto gel, and the detector senses the fluorescent tag.

What happens in the annealing step of PCR?

The primer binds to the target.

What is required for DNA replication, transcription, PCR, and dideoxy chain termination sequencing?

Complementary base pairing.

What is the result if a thermocycler runs at a constant high temperature?

DNA strands do not separate.

Which statements about DNA replication, transcription, and PCR are true?

All require a template strand and only DNA replication requires RNA primers.

What happens during DNA replication in a eukaryotic cell that does not occur in PCR?

Unwinding of the DNA helix by helicase.

Why does DNA migration occur in gel electrophoresis?

DNA migration is due to its negative charge.

What percent of the children from individuals II-2 and IV-4 will be carriers for an autosomal recessive disease?

50%.

Which indicates a trisomy in humans?

A somatic cell with 46 chromosomes and a Y chromosome.

What mechanism could preserve harmful recessive traits in a population?

Heterozygote advantage.

Which parents could produce a child with cystic fibrosis?

Ff x Ff.

What must be true for an individual to express an autosomal recessive trait?

They must have two recessive alleles.

What must be true for an individual to express an X-linked recessive trait?

XY individuals can express the trait with just one recessive allele.

What types of genetic disorders can be caused by nondisjunction?

Monosomy and aneuploidy.