Cell Cycle & Mitosis I
The purpose of the mitotic cell cycle is to produce daughter cells that __________.
a) have the same number of chromatids as the parent cell had chromosomes
b) have the same number of chromosomes as the parent cell but not the same genetic content
c) have a random assortment of maternal and paternal chromosomes
d) are genetically identical to the parent cell
e) None of the above are correct.
d) are genetically identical to the parent cell
DNA replication occurs in __________.
a) Prophase of mitosis
b) Cytokinesis
c) Metaphase of mitosis
d) G1 Phase of Interphase
e) S phase of Interphase
e) S phase of Interphase
When we say that an organism is haploid, we mean that __________.
a) its cells have a single set of chromosomes
b) It has half of a chromosome
c) Its cell have two sets of chromosomes
d) Its cells have half of one set of chromosomes
a) its cells have a single set of chromosomes
This is the name for a "nucleotide triplet" that corresponds to a specific amino acid.
What is a codon?
During translation, this is the site of the ribosome where the growing polypeptide chain is built.
a) A site
b) E site
c) P site
d) None of the above
c) P site
This term refers to the precise location of a gene on a chromosome.
What is a locus?
This is the region where two sister chromatids are attached to one another.
What is a centromere?
One event occurring during prophase is __________.
a) the synthesis of a new nuclear envelope
b) the beginning of the formation of a spindle apparatus
c) cytokinesis
d) Alignment of chromosomes in a single plane
b) the beginning of the formation of a spindle apparatus
What is the typical result when a diploid cell has completed meiosis?
a) two diploid cells
b) two haploid cells
c) four haploid cells
c) four diploid cells
c) four haploid cells
In many cases, more than one codon codes for the same amino acid. Because of this, we say that the code is __________.
a) inaccurate
b) incomplete
c) not specific
d) redundant
d) redundant
In a eukaryotic cell, transcription takes place __________.
a) on the cell membrane
b) in the rough endoplasmic reticulum
c) in the cytoplasm
d) on free ribosomes
e) in the nucleus
e) in the nucleus
This term refers to X chromosome inactivation in females, and can cause things such as calico cat patterns.
What are "Barr bodies"?
How many paternal chromosomes are in a somatic human cell that is not engaged in cell division?
a) 23
b) 46
c) 92
d) 184
e) None of the above are correct.
a) 23
Which of the following represents a mismatch or incorrect description?
a) metaphase: chromosomes line up on the equatorial plane
b) anaphase: there is movement of the chromosomes to the poles
c) prophase: chromosomes become more tightly coiled
d) metaphase: the nuclear envelope disappears
e) telophase: chromosomes begin to unwind
d) metaphase: the nuclear envelope disappears
Synapsis occurs during __________.
a) Prophase II
b) Cytokinesis
c) Metaphase I
d) Prophase I
e) Anaphase I
d) Prophase I
tRNA during protein synthesis is used to __________ .
a) Deliver amino acids to their proper site during protein synthesis
b) Attach mRNA to the small subunit of the ribosome
c) Guide ribosomal subunits out of the nucleus through the nuclear pores
d) Process mRNA
a) Deliver amino acids to their proper site during protein synthesis
During translation, amino acid elongation occurs until __________ .
a) All tRNAs are empty
b) The ribosome encounters a “stop” codon
c) The polypeptide is long enough
d) No further amino acids needed by the cell
b) The ribosome encounters a “stop” codon
A red bull is crossed with a white cow and all of the offspring are roan, an intermediate color that is caused by the presence of both red and white hairs. This is an example of genes that are __________.
a) nonhomologous
b) completely dominant
c) Polygenic
d) codominant
e) None of the above.
d) codominant
If a cell contains 40 chromatids at the start of mitosis, how many chromosomes will be found in each daughter cell at the completion of the cell cycle?
a) 10
b) 20
c) 30
d) 40
e) 120
b) 20
You would know that a dividing cell was a plant cell rather than an animal cell if you saw that __________.
a) it had microtubules
b) it had formed a cell plate
c) it had two pairs of centrioles during prophase
d) it had formed a cleavage furrow
e) All of the above.
b) it had formed a cell plate
Which of the following occurs during anaphase I?
a) Chromosomes line up on one plate.
b) The cell is haploid.
c) The nuclei re-form.
d) Sister chromatids separate and migrate toward opposite poles.
e) Homologous pairs separate and migrate toward opposite poles.
e) Homologous pairs separate and migrate toward opposite poles.
One strand of a DNA molecule has the following sequence: 3′-AGTACAAACTATCCACCGTC-5′. In order for that strand to be transcribed, there would have to be a specific recognition sequence, called a(n) __________, to the left of the DNA sequence indicated.
a) intron
b) promoter
c) AUG codon
d) exon
e) centromere
b) promoter
Which of the following statements correctly describes mRNA processing?
a) Introns are cut out of the primary transcript and spliced together at the end of the transcript.
b) Exons are cut out of the primary transcript, and the introns are spliced together.
c) Introns are cut out of the primary transcript, and the resulting exons are spliced together.
d) Exons are cut out of the primary transcript and transported to the endoplasmic reticulum.
e) Introns are cut out of the primary transcript and transported to the ribosomes.
c) Introns are cut out of the primary transcript, and the resulting exons are spliced together.
If a heterozygous plant is allowed to self-pollinate, what proportion of the offspring will also be heterozygous?
a) 1/4
b) 1/3
c) 1/2
d) 2/3
e) All of the offspring.
c) 1/2
Down syndrome is characterized by cells having three copies of chromosome 21. As a cell in an individual with Down syndrome prepares to enter mitosis, how many chromatids would be present?
a) 23
b) 46
c) 92
d) 94
e) None of the above.
d) 94
Which of the following processes does NOT occur in dividing bacteria?
a) Mitosis
b) DNA Replication
c) Binary Fission
d) Separation of the origins of replication
e) All of the above occur in dividing bacteria.
a) Mitosis
The diploid number of chromosomes in a certain animal is 8 (2n = 8). How do the four pairs of homologous chromosomes align and separate during meiosis?
a) Exactly two maternal and two paternal chromosomes always move to each of the two poles.
b) All 16 chromatids move together.
c) They align and assort independently to form any of 16 different combinations.
d) The first to move influences all the others.
e) All of the maternal chromosomes always move to one pole, and all the paternal chromosomes always move to the other pole.
c) They align and assort independently to form any of 16 different combinations.
What is a key difference with eukaryotic and prokaryotic gene expression?
a) RNA polymerase is only involved in eukaryotic gene expression
b) In prokaryotes, the RNA transcript is immediately available as mRNA and does not require processing
c) In eukaryotes, the RNA sequences function as termination signals
d) In prokaryotes, proteins are made directly from DNA, not RNA
e) All of the above.
b) In prokaryotes, the RNA transcript is immediately available as mRNA and does not require processing
During translation in a eukaryotic cell, __________.
a) ribosomes move into the nucleus
b) tRNA carries amino acid molecules to the nucleus, where they are added to a growing polypeptide chain
c) polypeptides are synthesized at ribosomes, according to instructions carried by mRNA
d) mRNA is synthesized by the bonding of free nucleotides to the bases on the template strand of DNA
e) ribosomes move out of the nucleus
c) polypeptides are synthesized at ribosomes, according to instructions carried by mRNA
In certain plants, tall is dominant to short. If a heterozygous plant is crossed with a homozygous tall plant, what is the probability that the offspring will be short?
a) 1
b) 1/6
c) 1/4
d) 0
e) 1/2
d) 0