Bio 93 Final

Pick the one that is true of MEIOSIS but not mitosis

homologous chromosomes pair up

DMEM is a solution commonly used by research labs to grow mammalian cells, as it is isotonic to many cell types and also helps maintain a constant pH. Suppose you make 2x concentrated DMEM, then add it to some human epithelial cells. The concentrated DMEM is

hypertonic to the cells, so the cells will get smaller

A sperm donor who has blood type B has a daughter who is type O and a son who is type A. Which of the following is a possible genotype for the sperm donor?

i IB

You have found a protein involved in substrate level phosphorylation in glycolysis. You would find this protein

in the cytosol

One way an EPSP (excitatory postsynaptic potential) could facilitate depolarization of the postsynaptic membrane is by

increasing the permeability of the membrane to Na+

Drugs used in the treatment of congestive heart failure may cause an increase in the concentration of potassium outside the cardiac muscle cells. This is most likely due to

inhibiting the sodium potassium pump

What do R loops represent?

introns

What fat makes the lipid bilayer more fluid?

phospholipids with carbon-carbon double bonds in hydrocarbon tails

Seed A and Seed B are germinated in dishes with water and light. Seed A is given pure oxygen, while Seed B is given normal air. After 10 days, which has occurred?

plant B is heavier than plant A

Spatial summation to reach threshold involves

synapses at more than one site

In a dihybrid test cross, the total number of possible gametes is

5; 4 from the sperm and 1 from the egg

Which of the following does NOT happen when a ligand binds to an intracellular receptor?

A kinase cascade amplifies the signal

In a cancer cell that ignores the M phase checkpoint, what is the first step you would expect to go awry?

Alignment on the metaphase plate

A normal mRNA that codes for a short polypeptide has the sequence AUGAAGUUUGGUUAA. You discover a mutant form of the mRNA which has two additional GG residues inserted immediately after the AUG. This is likely to

Alter the reading frame of the mRNA

Which of the following is NOT an example of a post-translational modification that might be required for protein function?

Alternative splicing by the spliceosome

A common feature of all lipids (fats, phospholipids, steroids) is that they

Are hydrophobic or amphipathic

Why can't the action potential travel backwards up the axon?

Because voltage-gated potassium channels are slow to close

If the Na+/K+ pump was inactivated, that would

Cause the resting membrane potential to rise (become less negative, depolarize)

Enzymes that break down proteins in the lysosome, get a tag (known as M6P) added to them in the ER & golgi. Then, a receptor recognizes that M6P tag in the golgi, pinches off in a transport vesicle, and directs those proteins to the lysosome. What do you predict will happen in cells that have MORE M6P receptors in the golgi?

Cells with more M6P receptors in the golgi will be more efficient at recycling engulfed material

When sodium chloride is added to water, which of the following happens?

Cl- is attracted to the hydrogen atoms in water

Which of the following would you expect to find on the INSIDE of a membrane vesicle traveling away from the trans face of the golgi?

Glycosylated side of a membrane glycoprotein

Active transport is important in pumping which of the following molecules across the plasma membrane?

H+

Oxygen is commonly found in the form of O2 because oxygen

has six valence electrons

The Meselson and Stahl experiment demonstrated for the first time that

DNA builds new strands by separating old strands

What is a benefit of mRNA vaccines over DNA vaccines?

DNA must enter the nucleus

A new DNA strand elongates in only one direction because

DNA polymerase can only add nucleotides to the 3' end

As described in lecture, dog that is EE Bb for coat color is

Demonstrating simple dominance in its melanin transporter

Addition of a drug that binds to the plus end of microtubules and prevents addition or loss of tubulin subunits to an actively dividing cell during prophase of mitosis would disrupt which of the following processes during prophase/prometaphase?

Formation of the mitotic spindle

An experimental herbicide kills plants by blocking the ATP synthase in thylakoids. This is most likely to

Increase the pH of the chloroplast stroma

Exposure to a specific drug "X" results in a decrease in blood levels of cholesterol in low-density lipoprotein particles. What is this drug "X" most likely to be doing?

Increasing receptor mediated endocytosis

If animals were given a drug that interfered with calcium being pumped into the sarcoplasmic reticulum after muscle contraction, what would fail to happen?

Myosin would cause continuous contractions until the ATP was used up

When the electron transport chain in a mitochondrion is active, which of the following occurs?

NADH is oxidized to NAD+

Which is the least common source of genetic variation resulting from meiosis?

Nondisjunction of homologous chromosomes in meiosis I

Which would be most likely to force a heart cell to express a liver protein?

Put liver transcription factors into a heart cell

In Vini's lab demonstration, you saw him use a 2-photon confocal microscope to do everything EXCEPT?

Put them to sleep for a short time

The energy released by changing ATP to ADP is

Required for vesicular transport

Select the gene least likely to be in the genome of a negative strand ssRNA virus

Ribosome proteins

Transcription factors act by

Stabilizing the transcription initiation complex

Which of the following is made of deoxyribonucleic acid?

TATA box

The citric acid cycle

Takes place in the mitochondrial matrix

Which of the following does NOT occur during mitosis?

The checkpoint to ensure cells are big enough to divide

What determines the resting membrane potential?

The leak permeability of the membrane to potassium

What would most likely happen if you transplanted a notochord onto a just-fertilized egg/zygote?

The organizer wouldn't be able to induce anything

What would happen to DNA if it was treated with an enzyme that hydrolyzes the covalent bond between nucleotides?

The phosphodiester bonds between deoxyribose sugars would be broken

Pink snapdragon flowers, the result of a cross between red and white flowers, are an example of incomplete dominance because

The red pigment is expressed at lower levels than in a red snapdragon

What would be the most likely consequence if a mutation arose in the gene for the reverse transcriptase of a retrovirus, while it was a provirus?

The virus would be produced, bud off, infect the next host cell, but then not be able to replicate its genome

Which of the following is most UNLIKELY to happen when a neurotransmitter is released?

Translocation of an intracellular receptor into the nucleus

Microtubules are shrunk by

Tubulin dimers falling off the plus end of the filament

Charging a tRNA requires all of the following EXCEPT

a start codon

16 alleles are known to exist for a given gene in a diploid organism. This means that any given individual of that species can have:

at most, 2 alleles for that gene

Which type of virus is most likely to degrade the host chromosome(s)?

bacteriophage in the lytic cycle

In Drosophila, bicoid protein would most likely be found

binding to DNA

A G-protein coupled receptor protein will have completed transcription on a

bound ribosome

A mouse exhibits the dominant trait of normal eyesight. The genotype of this mouse

can be determined by a test cross to a mouse that is phenotypically recessive

Epinephrine binds to receptors on the smooth muscles lining the walls of small blood vessels, causing them to constrict. In the presence of a bacterial toxin that blocks production of GTP, the blood vessels do not constrict when exposed to epinephrine. Which of the following is true in the presence of this toxin?

cyclicAMP levels in the cytoplasm are low

The formation of ATP by substrate-level phosphorylation requires

enzymes

True or false: Hydrophilic substances can pass through membranes more easily than hydrophobic

false

True or false: Some enzymes can turn an endergonic reaction to an exergonic reaction

false

PCSK9 is a molecule made by liver cells that degrades LDL receptors. It normally only occasionally removes the receptors, but patients with a mutation have overactive PCSK9, reduced LDL receptors, and familial hypercholesterolemia (FH). A new treatment called Evolucmab is a monoclonal antibody against PCSK9. Which is most likely true about Evolucmab?

it reduces blood cholesterol levels

The secondary immune response, in contrast to the primary immune response, utilizes

memory cells

Inhibiting the activity of an enzyme that is important in the hydrolysis of ester bonds would cause

more phospholipids

Addition of a drug that specifically blocks the function of myosin will immediately result in the disruption of

muscle contractions

Which is an example of organogenesis?

neurulation

At the end of meiosis I, the daughter cells are

not identical to each other

Researchers found that people who have a particular variant of a gene called ORMDL3 tend to have both asthma (in the lungs) and primary biliary cirrhosis (in the digestive system). This is an example of

pleiotropy

In neurons, exocytosis of vesicles containing the neurotransmitter acetylcholine occurs from the

presynaptic membrane

Which of the following does NOT occur in the Calvin cycle?

release of oxygen

Which is true of RNA polymerase but not DNA polymerase?

requires a promoter

Which is NOT a source of asymmetry in the early egg/zygote?

the involution of the dorsal lip during gastrulation

The microtubule organizing center in nondividing cells is where

the minus end of microtubules are anchored

An assigned female person born with an extra X chromosome is healthy and produces gene products from the X chromosome at normal levels. Which is most likely true?

their cells are likely to have two Barr bodies

True or false: Cells other than neurons/nerve cells can be electrically excitable

true