Bio Ch. 17 Cell Reproduction and Differentiation
In interphase,
A cell spends most of its life in this phase when growth occurs. Cells that are about to divide replicate their DNA.
how can we best define the term chromatid?
A chromatid is an individual strand in a replicated chromosome
Which of the following represents the flow of information within a cell?
DNA > RNA > protein
which of the following is NOT a rationale for using mRNA intermediates in gene expression?
DNA lacks the necessary information for protein production
the molecule that seals the gaps between the pieces of DNA in the lagging strand is
DNA ligase
which statement about DNA replication is FALSE?
DNA ligase adds nucleotides to the lagging strand
which of the following build(s) new strands of DNA?
DNA polymerase
phase during which most of the growth of a cell occurs is
G1 phase
Phase during which the cell prepares for cell division is
G2 phase
Which of the following lists the stages of the cell cycle in correct order?
Interphase, prophase, metaphase, anaphase, telophase
In prophase,
Microtubules form the mitotic spindle, and the nuclear envelope breaks up.
You have designed a drug that irreversibly binds to the P-site of the ribosome. What is the outcome for a growing bacterial cell?
Protein translation would fail to initiate because of the inability of the initiator tRNA to bind within the ribosome
Phase during which the cells DNA is duplicated is
S phase
If the nitrogenous base sequence in a molecule of DNA is AATGGTC on one side of a double helix, then the nitrogenous base sequence on the other side of the helix would be
TTACGAG
what must happen before a cell can begin mitosis?
The chromosomes must be duplicated
Which statement about DNA replication is CORRECT?
The leading strand is built continuously, and the lagging strand is built in pieces.
In metaphase,
The mitotic spindle is fully formed and chromosomes are lined up in the center of the cell.
When speaking of bonding patterns in DNA molecules, we can say that
The phosphate of one nucleotide is bonded to the sugar of the next nucleotide via covalent bonds, and the nitrogenous bases are held together by hydrogen bonds
The three principal structural components of a nucleotide are
a phosphate group, a deoxyribose sugar, and a nitrogenous base
a gene is expressed when
a protein is produced
as the cell cycle progresses, there are control mechanisms located at several ________, where the cell cycle may stop.
checkpoints
In telophase,
chromosomes become less condensed and new nuclear envelopes form. In cytokinesis the cytoplasm divides.
When a human cell matures and become specialized, the process it has undergone is
differentiation
Meiosis starts with a single diploid cell and produces
four haploid cells.
a short segment of DNA that represents the code for a specific protein is a ________.
gene
if the human genome were considered to be a large cookbook, which of the following would represent the individual recipes?
genes
which of the following are listed in order from largest (most inclusive) to smallest?
genome, chromosome, gene, nucleotide
during prophase one of meiosis,
homologous chromosomes stick together in pairs
Nirenberg and Matthaei are famous for________.
identifying the first mRNA triplet
which of the following is not a correct description of a stage of mitosis?
in prophase, the DNA replicates and the cell prepares for division
A cell preparing to undergo meiosis duplicates its chromosomes during
interphase
which of the following is true about genetic mutation?
it is a change in the DNA base sequence
a mutation in the DNA of an organism is passed on to offspring only when ________.
it occurs in cells that give rise to an egg or a sperm
________ contains codons and ________ contains anticodons
mRNA; tRNA
When do homologous chromosomes pair up?
meiosis I
When does reduction division take place?
meiosis I
How does the production of sperm differ from the production of eggs?
meiosis during sperm production produces four sperm cells, where as meiosis during egg production produces only one functional egg cell.
The first mRNA triplet discovered was a code for which amino acid?
phenylalanine
during what phase of meiosis does recombination occur?
prophase I
In anaphase,
sister chromatids separate and become full-fledged chromosomes that move to opposite poles.
which of the following act(s) as a decoder, reading mRNA cosmos and bringing the correct amino acid to the ribosome?
tRNA
which of the following statements is false?
the "words" of the genetic code often overlap. In other words, the end of one "word" often forms the beginning of the next "word".
When considering DNA replication, which of the following statements is not true?
the components of the new nucleotides are assembled as the new strand of DNA is being generated
which of the following statements best describes transcription?
the production of RNA from a DNA template
what is the name of the DNA sequence to which RNA polymerase attaches to a gene and assists in transcription initiation?
the promoter
what is the role of the A-site in translation?
to accept the next tRNA and its accompanying amino acid to the ribosome
which of the following is a way in which replication and transcription differ?
transcription copies only one side of the DNA molecule
the difference between transcription and translation is that
transcription is the process of producing the mRNA, and translation is the process of using the mRNA to assemble a sequence of amino acids that form a polypeptide
true or false. The semi conservative model of DNA replication states that each newly synthesized DNA molecule is composed of one parental strand of DNA and one newly synthesized complementary strand.
true
Somatic cell nuclear transfer
utilizes the nucleus of an adult somatic cell to provide the genetic information to produce a clone
When we say that the genetic code is "nearly universal," we mean that
with very few exceptions, the same codon codes for the same amino acid throughout the living world