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