BIO 183 Final Practice
Two F1 generation offsprings of a monohybrid cross have similar phenotypes. In order to determine whether those 2 organisms are homozygous dominant or heterozygous, one may attempt to
Do a testcross
Cortisol is a signaling molecule released in the blood stream by adrenal glands (Located in your lower back). Its effects on the brain are an example of which of the following?
Endocrine signaling
The advantages of using Ca2+ and cAMP downstream of G-protein-coupled receptors are
Enhancement of signal amplification and speed
Which of the following is true regarding extranuclear inheritance?
Extranuclear inheritance refers mainly to mitochondrial and chloroplast DNA
Intracellular receptors that affect gene expression (as is the case for steroid receptors, for instance) typically have faster effects that transmembrane receptors such as GPCRs or RTKs
False
The main function of glycoproteins in the cell membrane is
To give cells an identity that allows them to be recognized by other cells (ex immune system cells)
The process of converting an mRNA sequence into a polypeptide is called
Translation
Which of the following are produced during aerobic cellular respiration?
36-38 ATPs
The plasma membrane is best described as:
A double membrane of phospholipids arranged in a fluid-mosaic of lipids, proteins, and carbohydrate molecules
Which of the following structures would least likely be found as part of a bacterium?
A lysosome
A nucleotide mutation that converts a regular codon (coding for an amino acid) into a STOP codon is called
A nonsense mutation
Which of the following best describes proteasomes?
A proteasome is protein complex whose purpose is to hydrolyse ubiquinated proteins.
The main difference between active and passive transport across a cell membrane is
Active transport requires energy while passive transport does not
The sum of all intracellular reactions involved in the building up of macromolecules is called
Anabolism
The regulation of gene expression in eukaryotes and prokaryotes may take place at which of the following levels:
At the transcriptional level At the translational level At the post-translational level
The pattern of inheritance illustrated by the various blood types is an example of
Codominance
Okazaki fragment exist because
DNA polymerase III can only read DNA in the 3' to 5' direction
Polymers of macromolecules (carbohydrates, fats, and proteins) can be assembled from individual monomers by which process?
Dehydration (or condensation) reaction
Which of the following is a monosaccharide?
Fructose
During a typical cell cycle, the interphase is composed of which of the following phases
G1, S, G2 only
Which of the following best explains the process of photosynthesis
Photosynthesis decreases when chloroplasts are exposed to green light only
In eukaryotes, the process described in the previous question takes place mainly...
In/on the rough endoplasmic reticulum
Steroid hormones such as testosterone and estrogen (both small hydrophobic hormones) are known to bind to which of the following?
Intracellular receptors
The protein complexes that pull sister chromatids apart from each other along the spindle apparatus during mitosis are known as
Kinetochores
The signaling molecules that bind to receptors to activate them are also known as
Ligands
The 2 main stages of photosynthesis in chloroplasts are
Light reactions and Calvin cycle
Enzymes catalyze chemical reactions by
Lowering the activation energy necessary to start the reaction
In what phase of meiosis do homologous chromosomes line up in the middle of the cell?
Metaphase I
The final electron acceptor in the electron transport chain of thylakoids is
NADP+
Genes can be found on both strands of DNA. The strand that is being read in order to make mRNA is
The template strand
The purpose of the 5' cap on eukaryotic mRNA is
To allow the attachment of ribosomes
Which of the following is true about gene regulation during transcription?
Nucleosomes may be displaced or remodeled
During oxydative phosphorylation, the final electron acceptor at the end of the electron transport chain is
O2
Which of the following factors have the ability to denature an enzyme, thereby affecting its functionality?
Oven tempertaure, pH=14, and pH=1
In lungs, O2 moves freely across the cell membrane of alveoli, down its concentration gradient, and without the requirement of any carrier protein or any input of external energy. This is an example of
Passive diffusion
In cellular respiration, which of the following are products of glycolysis?
Pyruvate, ATP, and NADH
Which of the following best describes G-protein-coupled receptors
Receptor-associated, intracellular protein complexes composed of 3 subunits
Retroviruses such as HIV mostly utilize their host's machinery to make more viruses. However, to function properly, retroviruses may also need to incorporate (an) extra enzyme(s) that is/are normally not present in their host's proteome. This/these enzyme(s) is/are:
Reverse transcriptase and Integrase
DNA replication is known to follow which of the following patterns
Semi-conservative mechanism
Which of the following statements is/are correct about sex-linked traits
Sex-linked traits and mutations can affect males and females and Sex-linked genes are always found on the X or Y chromosome
The LacI gene is constitutively active, which suggests which of the following
The CAP protein is made continuously
Which of the following answers describes what happens to the Lac operon when Glucose is high and Lactose is low
The CAP protein would not bind to the CAP site, but the Lac repressor would bind to the operator
During the initiation of translation in eukaryotes, the first tRNA is brought into which site of which ribosomal subunit?
The P site of 60S subunit
Aminoacyl-tRNA synthetases are extremely specific enzymes. Without this high level of specificity,
The amino acid sequence of polypeptide would often be wrong
During cellular respiration, glycolysis takes place in which of the following?
The cytoplasm
Oxydative phophorylation takes place in which of the following?
The inner mitochondrial membrane
Some bacteriophages have a latent phase in their reproductive cycle during which they integrate their DNA in their host's genome. During this phase, they do not actually reproduce and/or kill their host cell. This phase is known as
The lysogenic cycle
Which of the following best describes the movement of small polar ions such as Na+, Cl-, K+, and Ca2+ across a regular cell membrane?
The membrane allows the movement of these ions only through specific channels and pumps
Which of the following is false about the repressor encoded by the lac regulatory gene?
The repressor is inhibited by beta-galactosidase
Which of the following is/are true about the two DNA strands that form a helix?
They are antiparallel and complementary to each other. In a gel electrophoresis, DNA would run toward the positive electrode
Which of the following is true about operons in general?
They are found primarily in prokaryotes and They are composed of a cluster of genes regulated by a single promoter region
Which of the following is true about miRNA and siRNA?
They both involve the recruitment of dicer and a RISC complex and They work by binding to mRNA and preventing its expression
Upon binding of a ligand, receptor tyrosine kinases do which of the following?
They dimerize, autophosphorylate, and trigger a cascade in intracellular signal transduction/phosphorylation
The main electron donor to photosystem 2, in the electron transport chain of the thylakoid membrane is
Water
A hypothetical cell whose plasma membrane is made of a phospholipid bilayer only (no channels or anything of that sort) is placed in a solution of 100mM NaCl. The intracellular NaCl concentration is 200mM. What would you expect to observe?
Water would move in the cell by osmosis
Which statement about ATP is correct?
a. ATP serves as an energy "currency" inside the cell b. The reaction of ATP -> ADP + P is coupled to endergonic reactions c. The reaction of ATP -> ADP + P is an exergonic reaction d. The main source of ATP production for an entire plant cells is its mitochondria
Which of the following roles is commonly performed by proteins?
a. Cytoskeletal support b. Catalysis of chemical reactions c. Formation of transmembrane receptors d. Intracellular transport
Which of the following factors affects plasma membrane fluidity?
a. Length of fatty acyl chains b. Presence of double bonds in the fatty acyl chains c. Presence of cholesterol
Which of the following is true about nucleosomes?
a. Nucleosomes are composed of histones arranged in a zig-zag pattern to make a 30nm DNA fiber b. Nucleosomes are made of 9 histones c. Nucleosomes contribute greatly to DNA compaction
Which of the following is true about telomerase
a. Telomerase extends the 3' end of DNA strands by a few nucleotides b. Telomerase activity decreases over time c. Telomerase contains its own template of repetitive nucleotide sequence
According to the theory of alternative splicing...
a.One gene may encode for more than one protein b.One sequence of mRNA may be split into several subunits c.Various tissues may express the same genes differently
Which of the following is true about transcription factors in eukaryotes?
a.They tend to bind DNA in the area of the TATA box (when present) b.They tend to bind DNA in the major grooves c.They often form complexes made of several subunits
Which of the following are you least likely to find inside a virus?
b. RNA polymerase
Which of the following is NOT a common DNA-binding motif for transcription factors?
beta-pleated sheet
The cloverleaf-shaped molecule that carries an anticodon at one end and an amino acid at the other is called
tRNA
Calcium is an important intracellular messenger
true
