Lecture Exam 3 bio 111

Enzymes that add acetyl groups to histone proteins are known as... a) HDACs b) DNMTs c) HATs d) DNA demethylases e) none of the above

c) HATs

In a transfer RNA, the acceptor stem... a) binds to the codon of a mRNA b) contains the anticodon loop c) binds to the amino acid d) all of the above e) none of the above

c) binds to the amino acid

What best describes the acetylation and methylation state of euchromatin? a) heavily methylated and hypo-acetylated b) heavily methylated and hyper-acetylated c) little to no methylation and hyper-acetylated d) little to no methylation and hypo-acetylated

c) little to no methylation and hyper-acetylated

Systemic (organism wide) cell signaling via the circulatory system is called... a) autocrine signaling b) direct cell to cell contact signaling c) paracrine signaling d) endocrine signaling e) synaptic signaling

d) endocrine signaling

In which subprocess of development does the final shaping of specific anatomical structures occur? a) cleavage b) cellular differentiation c) pattern formation d) morphogenesis e) none of the above

d) morphogenesis

What type of signaling occurs between a nerve cell and another cell? a) autocrine signaling b) paracrine signaling c) endocrine signaling d) synaptic signaling e) none of the above

d) synaptic signaling

In animal embryos, what is true about the rapid cleavage that occurs following fertilization? a) the number of cells increases and the size of the cell increases b) the number of cells decreases and the size of each cell decreases c) the number of cells increases but the size of each cell stays the same d) the number of cells increases but the size of each cell decreases e) none of the above

d) the number of cells increases but the size of each cell decreases

Which statement is not true concerning the genetic code? a) it is universal b) it is redundant c) the start codon specifies an amino acid d) the stop codons specify amino acids e) none of the above

d) the stop codons specify amino acids

Which statement best describes hydrophobic circulating ligands? a) they cannot pass through the plasma membrane and they bind to intracellular receptors b) they can pass through the plasma membrane and they bind to membrane bound receptors c) they cannot pass through the plasma membrane and they bind to membrane bound receptors d) they can pass through the plasma membrane and they bind to intracellular receptors e) none of the above

d) they can pass through the plasma membrane and they bind to intracellular receptors

Which option best completes the following sentence? A codon is made up of... a) two amino acids b) three amino acids c) two nucleotides d) three nucleotides e) none of the above

d) three nucleotides

A weak attractive force between nonpolar R groups due to charge fluctuations in the electron clouds of atoms is called... a) Van der Waals interactions b) hydrogen bonding c) hydrophobic interactions d) disulfide bridges e) none of the above

a) Van der Waals interactions

What stabilizes the tertiary structure of proteins? a) interactions between the amino acid R groups b) hydrogen bonding within the peptide backbone c) a and b d) none of the above

a) interactions between the amino acid R groups

Muscle cells do not express the gene for insulin. In those cells, which statement best describes what the chromatin structure would likely be in the area of the chromosome where the insulin gene is located? a) the insulin gene would be in an area of heterochromatin b) the insulin gene would be in an area of euchromatin c) the gene could be in either an area of euchromatin or heterochromatin d) none of the above

a) the insulin gene would be in an area of heterochromatin

Which statement is not true concerning codons? a) not all codons specify an amino acid b) all codons specify a different amino acid c) codons are a sequence of 3 nucleotide bases d) more than one codon can specify the same amino acid e) none of the above

b) all codons specify a different amino acid

A drug that binds to a receptor but does not stimulate the receptor to transduce a signal is known as... a) an agonist b) an antagonist c) a stimulant d) an opioid e) none of the above

b) an antagonist

Which option best completes the following sentence? When the initiation phase of translation is complete, the initiator tRNA will be located... a) in the 'E' tRNA binding pocket of the ribosome b) in the 'P' tRNA binding pocket of the ribosome c) in the 'A' tRNA binding pocket of the ribosome d) none of the above e) more information is needed

b) in the 'P' tRNA binding pocket of the ribosome

In protein structure, beta-pleated sheets are an example of... a) primary structure b) secondary structure c) super secondary structure d) tertiary structure e) quaternary structure

b) secondary structure

Which statement best describes multipotent cells? a) they are fully differentiated b) they can become only certain cell types c) they can become any cell type d) they can become any cell type except placenta e) none of the above

b) they can become only certain cell types

Which option best completes the following sentence? Ribosome binding sequences are found... a) in all messenger RNAs b) only in eukaryotic messenger RNAs c) only in prokaryotic messenger RNAs d) only in non-coding RNAs e) none of the above

c) only in prokaryotic messenger RNAs

In which subprocess of development does a radially symmetrical embryo start to develop axes that define the basic body plan? a) cleavage b) cellular differentiation c) pattern formation d) morphogenesis e) none of the above

c) pattern formation

Which statement or statements are true? a) all codons specify an amino acid b) all codons specify a different amino acid c) some codons do not specify an amino acid d) both a and b are true e) none of the above

c) some codons do not specify an amino acid

During translational elongation, the transfer RNA containing the next amino acid to be added to the growing protein, binds into which tRNA binding site on the ribosome? a) the E site b) the P site c) the A site d) it could be any of the above e) none of the above

c) the A site

Which option best completes the following sentence? In a charged tRNA, the amino acid is covalently bound to... a) the anticodon b) the anticodon loop c) the acceptor stem d) none of the above e) more info is needed

c) the acceptor stem

What affect does the rapid cleavage that occurs following fertilization have on the size of the embryo? a) the size of the embryo increases b) the size of the embryo decreases c) the size of the embryo remains the same d) more info is needed

c) the size of the embryo remains the same

A transfer RNA that does not have an amino acid covalently bound to it is said to be... a) unprimed b) unloaded c) uncharged d) unprepped e) none of the above

c) uncharged

What protein domains would a membrane bound receptor likely have? a) an extracellular ligand binding domain b) a transmembrane domain c) an intracellular signaling domain d) all of the above e) a and c only

d) all of the above

The charging reaction is carried out by... a) transcription factors b) histone acetyltransferases c) chaperones d) aminoacyl-tRNA synthetase enzymes e) none of the above

d) aminoacyl-tRNA synthetase enzymes

Enzymes that ensure proteins fold properly are known as... a) HATs b) DNMTs c) HDACs d) chaperone proteins e) DNA demethylases

d) chaperone proteins

The highest level of structure two or more proteins can achieve by interacting with each other is... a) primary structure b) secondary structure c) super secondary structure d) tertiary structure e) quaternary structure

e) quaternary structure

Signaling by a nerve cell to another cell is called... a) autocrine signaling b) direct cell to cell contact signaling c) paracrine signaling d) endocrine signaling e) synaptic signaling

e) synaptic signaling