BIO205 Quiz Questions

A solution with a pH of 8 has how many much greater a concentration of H+ ions in it compared to solution with a pH of 11?

1000 times

From its atomic number of 15, it is possible to predict that a neutral phosphorus atom has ________.

15 protons and 15 electrons

A bacterium undergoes 4 rounds of replication. How many of the descendant cells would still have a strand of DNA that was present in the original cell?

2

If a double-stranded DNA sample was composed of 20 percent thymine (T), what would be the percentage of guanine (G)?

30% G

In a monomeric nucleotide, the phosphate groups are attached to the _____ (number) carbon of ribose or deoxyribose.

5

Suppose the following sequence of nucleotides on a template strand is exposed at a replication fork. Note the 5' and 3' ends. 5' CCTAGGCTGCAATCC 3' A complementary RNA primer is formed on this strand beginning at the T underlined in the sequence. Which of the following represents the beginning of the sequence of the primer?

5' AGCCUAGG 3'

If one strand of a DNA molecule has the sequence 5'ATTGCA3', the other strand would have the sequence

5'TGCAAT3'

Which of the following is true for all endergonic reactions?

A net input of energy from the surroundings is required for the reactions to proceed.

Suppose a cell has the following molecules and structures: enzymes, DNA, cell wall, and mitochondria. This cell could be from: __________

A plant but not an animal

Two proteins can adhere tightly and specifically to each other. How can weak forces such as electrostatic attraction, van der Waals bonds, hydrogen bonds, and hydrophobic forces lead to such strong adherence?

Adherence can become quite strong by having many individually weak interactions cumulatively involved in molecular adherence

Which of the functional groups below acts most like a base in water?

Amino

Which of the following is not a component of a nucleotide?

An amino functional group

Lysosomes are classified as part of the endomembrane system because

Are formed by products which were synthesized by the ER and Golgi

Steroids are considered to be lipids because

Are poorly soluble in water (hydrophobic)

Which of the following statements concerning the double helix structure present in DNA molecules is correct?

Base pairing between strands always involves one purine base and one pyrimidine base.

The reaction which joins two monomers to form a dimer is a ________ reaction, and in this reaction a molecule of water is __________

Condensation Produced

Which choice is utilized by eukaryotes to control their gene expression that is NOT used in bacteria?

Control of chromatin remodeling

Triglycerides are not amphipathic molecules because they

Do not have a polar or charged region

The motor protein responsible for the bending of a flagellum (for example, during sperm motility) is :________

Dynein

Nitrogen (N) is more electronegative than hydrogen (H). Which of the following is a correct statement about the atoms in ammonia (NH3)?

Each hydrogen atom has a partial positive charge; the nitrogen atom has a partial negative charge.

The evolutionary process which gave rise to mitochondria and chloroplasts is ______

Endosymbiosis

Whenever energy is transformed, there is always an increase in the ________.

Entropy of the universe

The statement that energy is neither created nor destroyed is the _____ law of thermodynamics.

First

The cohesive properties of water arise from its abundant _______ bonds

Hydrogen

In a fully folded cytoplasmic protein (like actin), where would you expect a hydrophobic residue like valine to be located?

In the interior of the protein, away from water

In the presence of glucose, the lac operon is not transcribed. One way that glucose causes this is by inhibiting transport of lactose into the cell. This action is called _______ exclusion.

Inducer

People with the disease progeria have cells with an abnormally shaped nucleus. Progeria probably affects which cytoskeletal system?

Intermediate filaments

Which of the following is a property of the lipid membrane of a cell?

Is a selectively permeable structure

What is the function of the enzyme helicase?

It breaks hydrogen bonds and separates strands of the DNA molecule

Which of the following statements about the DNA in one of your brain cells is TRUE?

It is the same as the DNA in one of your heart cells.

In comparison to eukaryotes, prokaryotes ________.

Lack a nucleus, while eukaryotes have one

Which of this organelles has an acidic interior and contains hydrolytic enzymes?

Lysosome

Which of the following correctly matches a cytoskeletal component with one of its functions?

Microtubules form tracks for transport of vesicles.

This organelle is the powerhouse of the cell, synthesizing ATP for use throughout eukaryotic cells.

Mitochondria

A molecule with the chemical formula C6H12O6 is probably a(n)

Monosaccharide

What does it mean to say the genetic code is redundant?

More than one codon can specify addition of the same amino acid

Fill in the blank: The special stretch of amino acids which causes a protein to be imported into the nucleus is the :_________

Nuclear Localization Signal

A bacterial cell's DNA is found in its __________ region.

Nucleoid

Which statement is true of intermediate filaments?

One example of intermediate filaments is the keratin family.

Which of these organelles is not considered part of the endomembrane system? Golgi Rough ER Peroxisome Smooth ER

Peroxisome

Which organelle contains the enzyme catalase, which processes peroxide?

Peroxisome

Water is an excellent solvent. Based on your knowledge of the polarity of water molecules, the solute in the center of this ring of water molecules is most likely

Positively charged

What is one major difference between eukaryotic versus prokaryotic DNA replication?

Prokaryotic chromosomes have one origin of replication, while eukaryotic chromosomes have many.

Which organelle or structure is involved in the production of proteins destined for secretion?

Rough ER

Suppose you are studying an organism with a branched metabolic pathway synthesizing two related amino acids (D and F). If there is a genetic defect affecting enzyme (3), how could you be sure that adequate amounts of the amino acid F are available for the organism to grow?

Supplement with E

Which of the following is TRUE when comparing an uncatalyzed reaction to the same reaction with a catalyst?

The catalyzed reaction will have the same ∆G.

All three domains (Bacteria, Archaea, and Eukarya) utilize the same genetic code. Therefore, which of the following statements would most likely be correct?

The genetic code evolved before the different domains diverged.

CAP is an activator for the lac operon. If a mutation inactivates the DNA site bound by CAP (the CAP site) near the lac promoter, you would expect that

The lac genes would be expressed inefficiently even in the presence of lactose.

You have just discovered an organism that lives in extremely hot environments. Which of the following would you predict to be TRUE about the phospholipids in its membranes, compared to phospholipids in the membranes of organisms that live in warmer environments?

The membrane phospholipids of warm-adapted organisms will have more saturated hydrocarbon tails

Which of these statements about a phospholipid bilayer is INCORRECT?

The polar heads face away from the watery environment

The term major groove refers to

The portion of the DNA double helix where the backbones are more separated

Why is it that RNA can catalyze reactions, but DNA cannot?

The tertiary structure of RNA is a highly folded single strand

A covalent bond is likely to be nonpolar when ________.

The two atoms sharing electrons are equally electronegative

Why are lipids (and proteins) free to move laterally in a membrane?

There are no covalent linkages between the lipids of the membrane

Which of these aspects of phospholipids is most important to their property of forming lipid bilayers?

They are amphipathic.

Eukaryotic enhancer elements include all of the following except:

They can substitute for the promoter in recruiting RNA polymerase

What is the function of DNA Polymerase III?

To add nucleotides to the 3' end of a growing DNA strand

The chromosomal structural abnormality in which an entire segment is attached to a different chromosome is a(n) _____________

Translocation

Which monomer of a cytoskeletal element is used to form cilia and flagella?

Tubulin

Each phospholipid has ______ (how many?) fatty acid tails attached to the glycerol linker molecule.

Two

How many electrons are involved in a single covalent bond?

Two

Reactants which are capable of forming products in a chemical reaction must first overcome a thermodynamic barrier known as the reaction's ________________.

activation energy

What is the advantage to a prokaryote of altering its pattern of gene expression?

allowing rapid response to environmental changes

Many bacterial genes are part of gene regulons. The advantage of a regulon is that it

allows large numbers of genes to be under the control of the same transcriptional regulatory protein.

Which of the following is NOT synthesized from a DNA template?

amino acids

Allosteric inhibition results from

binding of regulatory molecules at sites other than the active site

During formation of tertiary structure, the linkage of sulfur containing cysteine residues is termed

disulfide linkage

Which of the following are purine nitrogenous bases?

guanine (G) and adenine (A)

The greatest expression (transcription) of the lac operon occurs when lactose levels are _______.

high and glucose levels are low.

Side chains (R groups) of amino acids

might be electrically charged, uncharged polar, or nonpolar

The point mutation resulting in sickle cell disease changes one base pair of DNA so that a codon now codes for a different amino acid. This is an example of a _________

missense (point) mutation

Suppose you discover a new amino acid. Its R-group contains only hydrogen and carbon. You would classify this amino acid as

nonpolar

Which of the following correctly ranks structures in order of size from smallest to largest?

nucleotide- codon- gene- genome

If you disrupt all of the hydrogen bonds in a protein, which level of structure would remain?

primary

Post-translational control will affect gene expression at the level of

protein

The interaction of four individual folded polypeptide chains to make a functioning hemoglobin protein is an example of _____ structure.

quaternary

Forming an alpha helix is an example of _______ structure

secondary

Which of these is most permeable to a phospholipid bilayer?

small gasses such as CO2

Which of these is a possible exception to the central dogma of molecular biology?

some viruses transfer information from RNA to DNA

The primary RNA transcript of the chicken ovalbumin gene is 7700 nucleotides long, but the mature mRNA that is translated on the ribosome is 1872 nucleotides long. This size difference occurs primarily as a result of:

splicing

Which of the following is not a role of proteins in the human body?

store heritable genetic information

The backbone of a DNA double helix is made up of an alternating sequence of

sugar and phosphate groups.

Which of the following levels of gene expression allows the greatest savings in materials and energy sources at the expense of a slower speed of effect?

transcriptional control

A molecule which is oxidized in a reaction________.

typically decreases its potential energy

Under what condition does the CAP protein increase transcription of the lac operon?

when bound to cAMP