Final, practice

Two F1 generation offsprings of a monohybrid cross have similar phenotypes. In order to determine whether these 2 organisms are homozygous dominant or heterozygous, one may attempt to

Do a testcross

In prokaryotes, the processing of mRNA would include

Does NOT add a 5' cap, add a 3' poly-a tail, or remove introns.

Testosterone (produced by testes) activity on hypothalamic neurons (in the brain) is an example of which of the following?

Endocrine Signaling

Which of the following is true regarding extranuclear inheritance?

Extranuclear inheritance refers mainly to mitochondrial and chloroplast DNA

When ligands such as growth factors bind to receptor tyrosine kinase (RTKs), they may regulate cellular proliferation (tissue growth) by activating cyclin-dependent kinases (CDKs)

False, RTKs and CDKs are different.

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, intracellular is slower.

The main enzyme involved in RNA elongation during transcription is called tRNA synthetase

False, it is called telomerase.

Ribosomes in prokaryotes and eukaryotes are identical in shape and size.

False, prokaryotes are 70s (50s big, 30s small) and eukaryotes are 80s (60s big, 40s small). Not linear.

The following cartoon represents a G-protein-coupled receptor (GPCR)

False, this is of a RTK.

The 3 general mechansims that allow horizontal (lateral) gene transfer in prokaryotes are transduction, transformation and binary fission

False, transduction, transformation, and conjugation

Nucleotides in a single-stranded mRNA are interconnected through hydrogen bonds.

False. It is a phosphodiester bond

The method you used in lab to insert a GFP-encoding plasmid in bacteria is called

Transformation

The process of converting an mRNA sequence into a polypeptide is called

Translation

The pattern of inheritance illustrated by the various blood types is an example of

Codominance

The main function of Major histocompatibility complexes in the cell membrane is

To give cells an identity that allows them to be recognized by other cells

Which of the following are produced during muscle cell fermentation (often called anaerobic workout)?

2 ATPs and lactic acid

The cloverleaf-shaped molecule that carries an anticodon at one end and an amino acid at the other is called

tRNA

Which of the following RNA sequence would you expect to be synthetized from the following DNA strands Template: 5' ATC GCC TCA TTA ACT 3' Coding: 3' TAG CGG AGT AAT TGA 5'

3' UAG CGG AGU AAU UGA 5'

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 plasma membrane is best described as

A semi-permeable membrane that allows the free movement of water, gases, and small hydrophobic molecules. A double membrane of phospholipids arranged in a fluid-mosaic of lipids, proteins, and carb molecules

During the initiation of translation in eukaryotes, the first tRNA is brought into which site of which ribosomal subunit?

A site

In cellular respiration, which of the following are products of glycolysis?

ATP and NADH

Which statement about ATP is correct?

ATP serves as an energy "currency" inside the cell The reaction of ATP -> ADP + P is coupled to endergonic reactions The reaction of ATP -> ADP + P is an exergonic reaction The main source of ATP production for an entire plant cells is its mitochondria

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

At the end of the DNA replication process, telomerase activity is higher

At the 3' end of the leading strand

You would expect the N-terminus of a protein to be synthetized by a ribosome

At the beginning of translation

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 protein complexes that pull sister chromatids apart from each other along the spindle apparatus during mitosis are known as

Centrioles

Which of the following is commonly performed by proteins?

Cytoskeletal support, catalysis of chemical reactions, formation of transmembrane receptors, and intracellular transport

The molecule would most like be found in which of the following?

DNA bc of the implied H on the 2'.

Okazaki fragments exist because

DNA polymerase III can only read DNA in the 3' to 5' direction

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 transport

During the process of translation, the elongating polypeptide is transferred between which sites of the ribosome?

From A to P site

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 works best in the red and blue ranges of the visible spectrum

Which of the following is true about operons in general?

Primarily in prokaryotes They are composed of a cluster of genes regulated by a single promoter region

The distribution of body height in humans follows a bell-shaped curve. This distribution can best be explained by which of the following phenomena?

Human body height is regulated by polygenic inheritance

Polymers of macromolecules (carbohydrates, fats, and proteins) can be broken down into individual monomers by which process?

Hydrolysis

Lysosomes are involved primarily in

Hydrolysis of old organelles and unwanted molecules on the cell

In eukaryotes, the process described in the previous question (translation) takes place...

In the cytoplasm In/on the rough endoplasmic reticulum

Steroid hormones such as testosterone and estrogen are known to bind to which of the following?

Intracellular receptors

On the following cartoon that we used to illustrate a process ealier this semester, the upper strand is known as

Lagging Strand

In the male reproductive systems, the cells responsible for testosterone production are mainly

Leydig cells

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

Which of the following is a disaccharide?

Maltose

In what phase of meiosis do homologous chromosomes line up in the middle of the cell?

Metaphase I

What polypeptide sequence would you expect to be translated from the following unprocessed eukaryotic RNA sequence 3' AAG AUC UAA - UAUi UACi - ACC GUA 5'

N-terminus Met-Pro-Asn-Leu-Glu C-terminus

During oxydative phosphorylation, the final electron acceptor at the end of the electron transport chain is

NADH

The final electron acceptor in the electron transport chain of the thylakoid membrane is

NADP+

Which of the following is false about the repressor encoded by the lac regulatory gene?

The repressor is inhibited by beta-galactosidase (it is, however: The repressor binds to the operator; The repressor is the product of the LacI gene The repressor is active (bound to DNA) when lactose is not present

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 nucleosomes?

Nucleosomes are composed of histones arranged in a zig-zag pattern to make a 30nm DNA fiber Nucleosomes are made of 9 histones Nucleosomes contribute greatly to DNA compaction

Which of the following is true about gene regulation during transcription?

Nucleosomes may be displaced or remodeled

According to the theory of alternative splicing...

One gene may encode for more than one protein One sequence of mRNA may be split into several subunits Various tissues may express the same genes differently

The Golgi apparatus is primarily involved in

Protein sorting/routing

Which of the following are you least likely to find inside a virus?

RNA polymerase (you can find single-stranded DNA, enzymes, and single stranded RNA)

Which of the following best describes G-protein-coupled receptors

Receptor-associated, intracellular protein complexes composed of 3 subunits

In the absence of DNA polymerase 1, a cell would be unable to

Remove the primers

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. Sex-linked genes are always found on the X or Y chromosome

Which of the structures would least likely be found as part of a bacterium?

Smooth endoplasmic reticulum (commonly found: cell wall, plasma membrane, ribosome)

Which of the following is true about telomerase

Telomerase extends the 3' end of DNA strands by a few nucleotides Telomerase activity decreases over time Telomerase contains its own template of repetitive nucleotide sequence

Which of the following factors have the ability to denature most enzymes, thereby affecting their functionality?

Temperature, pH, concentration

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

The LacI gene is constitutively active, which suggests which of the following

The Lac repressor is made constantly

The cartoon from the previous (DNA replication) question represents a process that takes place during which phase of the cell cycle?

The S phase

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 cytosol

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 factors impact plasma membrane fluidity?

The presence of cholesterol

Which of the following is/are true about the two DNA strands that form a helix?

They are antiparallel and complementary to each other They are linked to each other by hydrogen bonds In a gel electrophoresis, DNA would run toward the positive electrode

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

Which of the following is true about transcription factors in eukaryotes?

They tend to bind DNA in the area of the TATA box They tend to bind DNA in the major grooves They often form complexes made of several subunits

Which of the following is true about miRNA and siRNA?

They work by binding to mRNA and preventing its expression

If helicase truly unzipped your genes, your pants would constantly fall off. This whole genetics thing is a big scam!

This is the answer.

If the following mutation took place in an RNA strand, it would be called a missense mutation Before mutation 5' UGG CAA ACU CUG 3' After mutation 5' UGG CAU ACU CUG 3'

True, before CAA would create Gln and after CAU would create His.

Calcium is an important intracellular messenger

True, calcium is.

Based on body size only, you would expect a mouse to have an easier time conserving heat than a dog

True, the mouse is smaller.

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

When the receptor from the previous question is activated, the direct intracellular response would most likely be

Which are you talking about? GPCR or RTK

The bond that connects the carboxyl end of an amino acid with the amino end of another one is

a peptide bond

Which of the following is not a common DNA-binding motif?

beta-pleated sheet (common: Helix-turn helix, Zinc finger, and leucine zipper)

What type of enzyme inhibition is represented below?

competitive inhibition

Match the level of protein structure on the left with the appropriate description on the right.

i. Primary: linear sequence of amino acids ii. Secondary: alpha helix iii. TertiaryL 3-D shape of polypeptide chain iv. Assembly of several polypeptide subunits

The advantages of using Ca2+ and cAMP downstream of G-protein-coupled receptors are

signal amplification and speed