bio exam 1

Replication is the synthesis of _______, while transcription is the synthesis of _______.

an exact copy of DNA; an RNA copy of DNA

The membrane structure shown in the diagram forms in water because the individual phospholipids

are amphipathic.

The three amino acids shown

are hydrophilic.

List the four states of matter starting with the stage in which the atoms are least compact:

plasma, gas, liquid, solid

Which of the following molecules will cross a plasma membrane most easily?

Testosterone

Which of the following pairs has similar chemical properties?

12C and 14C

Acid rain is a serious environmental problem. A sample of rainwater collected in the Adirondack Mountains had an H+ concentration of 1.0 ×10-4 mol/L. The pH of this sample was

4.

Earth is approximately _______ years old.

4.5 billion

. According to the figure, how many hydrogen bonds would there be in a DNA sequence of 20 base pairs in which there are five A-T and fifteen C-G pairs?

55

Which of the following spherical cells would exchange the greatest amount of substances and waste products with its environment relative to its internal chemical activity?

A 1 micrometer cell

Nonpolar molecules would likely exhibit which type of bonds or interactions?

A or E

The reaction shown in the diagram occurs during the formation of which protein structure?

a. Peptide backbone

Which component of an atom does not significantly add to its mass?

Electron

What is the difference between "free" and "attached" ribosomes?

Free ribosomes are in the cytoplasm, whereas attached ribosomes are anchored to the endoplasmic reticulum. Free ribosomes produce proteins in the cytoplasm, whereas attached ribosomes produce proteins that are inserted into the ER for processing and transport.

These fatty acids are acidic because of the presence of a _______ in the molecules.

a. carboxyl group (—COOH)

Which of the following problems for understanding the chemical evolution of life was solved by the discovery of ribozymes?

If nucleic acids appeared before proteins, the proteins couldn't have been the first catalysts. If proteins are needed for life, nucleic acids must have appeared first, so that the proteins could be made.

Which of the following statements about the nuclear envelope is true?

It contains pores for the passage of large molecules. It is composed of two membranes.

Which of the following statements about starch is false?

It has properties very similar to those of cellulose.

You have isolated an unidentified liquid from a sample of beans. You add the liquid to a beaker of water and shake vigorously. After a few minutes, the water and the other liquid separate into two layers. To which class of large biological molecules does the unknown liquid most likely belong?

Lipids

The organelle shown in the figure below is found in all cells but is most numerous in cells requiring a large amount of energy (e.g., liver cells). What is the name of this organelle?

Mitochondria

Which of the following organelles were once independent prokaryote organisms?

Mitochondria and chloroplasts

Nucleic acids and proteins are both polymers made of a set of monomers. Complete the following analogy: _______ are to nucleotides as side chains are to amino acids.

Nitrogenous bases

Yeast is cultured in the presence of radioactive phosphate, and the following biological molecules are purified from the cells. Which of the purified molecules should be most radioactive?

RNA

. Which of the following is not one of the major steps in the hypothesis‒prediction approach?

Stating an opinion

A A T G C G A

T T A C G C T

Which statement about amphipathic fatty acids is true?

The heads are polar and hydrophilic.

What kind of bond leads to a "kink" in the cis-oleic acid but not in the trans-oleic acid, as shown in the figure?

b. C=C

According to the figure, which of the following events must have been occurring between the existence of the "RNA world" and the evolution of the first cells?

b. The formation of cell membranes a. The production of oxygen by cyanobacteria

If a hemoglobin exposed to high temperatures is returned to normal temperature in the presence of chaperone proteins, it will refold _______ and _______ function.

b. correctly; regain

All living organisms can be assigned to one of three separate

c. domains.

Tyrone Hayes collected frog and water samples from eight widely separated sites across the U.S. and studied the incidence of abnormalities in frogs exposed to different levels of atrazine. This was a(n) _______ experiment.

comparative

The experiment depicted in the figure supports which of the following hypotheses?

e. Life comes from preexisting life.

. Calcium has an atomic number of 20 and an atomic weight of 40.08. From this information it can be determined that this element

has at least two isotopes.

After observing that fish live in clean water but not in polluted water, researchers state that "polluted water kills fish." This statement is an example of a(n)

hypothesis.

. The experiment shown in the figure, which was performed in the 1950s,

led to no meaningful conclusions, because there was no lightning in Earth's early environment.

The membranes of the endoplasmic reticulum are continuous with the membranes of the

nuclear envelope.

You look at the label on a container of shortening and see the words "hydrogenated vegetable oil." This means that during processing, the number of carbon-carbon double bonds in the oil was decreased and the

oil is now solid at room temperature.

A simple sugar with the formula C5H10O5 can be classified as a

pentose

The ability of _______ is essential for the existence of ribozymes.

single-stranded RNA molecules to bond with parts of themselves