Human Anatomy & Physiology Ch#4 Q&A – Flashcards
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Which of the following represents the structure of a nucleotide?
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Phosphate - Sugar - Base
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Which of the following DNA molecules is the most stable?
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GCGTGCAC
CGCACGTG
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Double - stranded DNA consists of two antiparallel strands, meaning that one strand is oriented in the 5' to 3' direction, while the other is oriented in the 3' to 5' direction.
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True
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In DNA, which nitrogenous base pairs with adenine?
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Thymine
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Cytosine and guanine form three hydrogen bonds between one another.
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True
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Which of the following is true of both mRNA and tRNA?
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Uracil may be present.
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Where in the cell does transcription occur?
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In the nucleus
(Transcription must take place in the nucleus becoz that is where the dna is located)
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What is the product of transcription?
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mRNA
(The product of transcription is mRNA)
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Translation is the synthesis of __________________
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Proteins from mRNA.
(In translation, mRNA is read to synthesize proteins)
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Which of the following occurs as the ribosome shifts down the mRNA by a distance of three nucleotides?
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The tRNA that was in the P site moves into the E site.
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What happens when a stop codon is encountered in mRNA?
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The ribosomal complex falls apart and the protein is released into the cell.
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In translation, the intial tRNA is in the A site of the ribosome.
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False
(it occupies the P site on the ribosome)
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A codon of tRNA is complementary to an anticodon of mRNA.
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False
( The anticodon of the tRNA is complementary to the codon of the mRNA)
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Which of the following combinations are correctly matched?
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ribosome - protein synthesis
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Which of the following occurs as the ribosome shifts down the mRNA by a distance of one codon?
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The tRNA that was in the A site moves into the P site.
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If a protein is 100 amino acids, during translation how many of these entered via the A site of the ribosome?
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99
(The first tRNA binds initially to the P site of the ribosome. All successive tRNAs enter the A site and then the P site.)
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The large ribosomal subunit joins the translation initiation complex after the small subunit has already joined.
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True
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Which of the following statements is false about genes?
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Once a gene is turned on, it is activated in all cells.
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In translation, the initial tRNA binds to which ribosomal site?
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P site
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How does DNA influence the synthesis of lipids, carbohydrates, and steroids?
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The proteins that DNA codes for catalyze the reactions that synthesize these compounds.
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During protein synthesis, tRNA carrying amino acids bind to the ribosome at the
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P and A sites
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The first organelle to process a new protein after synthesis is the
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rough endoplasmic reticulum.
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A segment of DNA that codes for the production of a molecule of RNA is known as a(n)
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gene
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The complementary mRNA strand synthesized from the DNA sequence of CTGAC would be
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GACUG
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Which of the following is a true statement concerning protein synthesis?
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Transcription occurs in the nucleus and translation occurs in the cytoplasm.
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Which form of RNA is responsible for holding an amino acid in anticipation of protein synthesis:
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tRNA
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During translation, tRNA binds to the
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large subunit of the ribosome.
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RNA polymerase begins its action at the ____________ and finishes at the ______________
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Promotor; Terminator.
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The synthesis of messenger RNA is called translation.
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False
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Personality traits, such as sex drive and aggression , are not influenced by DNA.
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False
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The anticodon is the three base sequence on the messenger RNA that binds with the codons of the transfer RNA.
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False
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The enzyme ___________ unzips and unwinds the DNA molecule.
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Helicase
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Which of the following statements about DNA replication is TRUE?
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The leading strand is replicated continuously, while the lagging strand is replicated discontinuously.
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DNA replication results in two identical daughter molecules each consisting of one old (original) strand and one newly - synthesized strand.
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True
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The point where separation of the DNA occurs in called the replication fork.
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True
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Which of the following events does NOT occur in prophase of mitosis?
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The chromosome are replicated.
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The mitotic spindle fibers attach to chromosomes via special structures called______________
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Kinetochores
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Which of the following statements about microtubules during anaphase is TRUE?
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Those attached to chromosomes shorten, while those that are unattached elongate.
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Centromeres divide during metaphase.
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False
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Which of the following is the results of meiosis?
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Four genetically different, haploid gametes.
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UV radiation can cause changes to the DNA sequence known as_______________
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mutations
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Which of the following is NOT a possible stimulus to initiative cell division?
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Contact inhibition
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Which phase demonstrates tetrads lining up along the metaphase plate?
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Metaphase I
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What is the name of the structure that develops during late anaphase and/or early telophase to help the cell divide into two new cells?
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Cleavage furrow
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Which of the following takes place during interphase?
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DNA replication
organelle replication
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Which of the following events occurs during Prophase I?
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All of these choices are correct.
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How many bivalents are formed in a cell with 46 chromosomes at the beginning of meiosis I?
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23
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Which of the following events occurs during anaphase I ?
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Separation of homologus chromosomes
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At the end of meiosis I, there are two haploid cells, each with two chromatids per chromosome.
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True
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The period between meiosis I and II is called interkinesis.
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True
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The spindle apparatus is fully formed by the end of _____________
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Prometaphase II
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Separation of______________ occurs in anaphase II of meiosis.
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sister chromatids
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Which of the following is a correct description of the products of meiosis?
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Four haploid cells, with each chromosome consisting of a single chromatid.
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Replication of chromosomes occurs between meiosis I and meiosis II.
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False
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Homologus pairs of chromosomes line up at the metaphase plate during metaphase II.
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False
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Which of the following events would NOT take place if mitosis was stopped before the beginning of anaphase?
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Cleavage furrow formation
Sister chromatids' migration to opposite poles
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As helicase unwinds the DNA molecule, the separated strands are kept apart by DNA polymerase.
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False
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The three base sequence in the transfer RNA is the codon.
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False
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All the proteins in an organisms is called a _____________
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Proteome
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The set of three nucleotides on a molecule of tRNA is called a(n) _______________
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anti-codon
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The amino acids carried by the tRNA are eventually joined to one another by ___________________________bonds.
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peptide
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Transcription occurs when ________________
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a messenger RNA molecule is synthesized from DNA in the nucleus.
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The system that enables 4 nucleotides to dictate the sequences of millions of proteins is called the ____________
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genetic code
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In chromatin, DNA winds around disc-shaped clusters of eight proteins called _____________
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histones
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Translation occurs when ________________.
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the blueprint of the RNA molecule is used to bind amino acids together to form proteins.
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The first organelle to process a new protein after synthesis is the __________________.
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rough endoplasmic reticulum
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Which form of RNA is responsible for holding an amino acid in anticipation of protein synthesis?
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tRNA
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During translation, tRNA binds to the __________________.
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large subunit of the ribosome.
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The sequence for protein synthesis is translation, then transcription.
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False
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After cytokinesis, the cell enters the G1 phase.
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True