Biology- Unit 2

Which of the following conclusions is most clearly supported by the representations of nucleic acid #1 and nucleic acid #2 ?

Nucleic acid #1#1 contains adenine-thymine base pairs, whereas nucleic acid #2#2 does not.

Which of the following functional differences between the rough and smooth ER is explained by the structural differences between them?

Rough ER can synthesize and package proteins for export, and smooth ER cannot.

Based on the model presented in Figure 1, which of the following outcomes will most likely result from a loss of protein X function?

The membrane potential will be disrupted by an increase in K+ concentration inside the cell.

Which of the following best describes the formation of the bond shown in Figure 1?

A covalent bond is formed between a carbon atom and a nitrogen atom along with the formation of H2O.

Which of the following statements best predicts the effect of increasing the permeability of the mitochondrial membranes to large molecules?

ATP production will decrease because of an increase in the occurrence of uncontrolled chemical reactions.

Which investigation will help determine whether the new membrane protein is a channel protein involved in membrane transport?

Add more of the proteins to the plasma membrane and measure the rate of the particle movement.

Which of the following best describes the numbered areas?

Areas 1 and 3 are polar, since the membrane molecules are aligned with water molecules.

Which of the following data would support the alternative hypothesis?

Cells with mutated aquaporins exhibit moderate turgor pressure and are hypertonic.

Which of the following best describes a process that occurs within the Golgi complex?

Enzymatic modification of newly synthesized integral membrane proteins.

Which of the following claims is scientifically accurate and consistent with an observation that a decrease in lysosome production within a cell leads to a decline in mitochondrial activity?

Fewer lysosomes will be available to break down macromolecules to provide the necessary nutrients for cellular respiration.

Which of the following best predicts the effect of not having ATP available to supply energy to this process?

H+ ions will stop moving through the protein.

Based on Figure 1, which of the following best describes how the properties of water at an air-water interface enable an insect to walk on the water's surface?

Hydrogen bonds between molecules at the surface of the water provide surface tension, which allows the water surface to deform but not break under the insect.

Which of the following observations would best support the alternative hypothesis described above?

In both plant cells and fungal cells, the cell wall surrounds the outside of the cell membrane.

Of the following, which additional investigation can be used to determine when the cells are in an isotonic solution?

Increasing the salinity of the environment a little at a time until the ATP usage reaches a minimum.

Which procedure should be done next to gather data needed to meet the scientist's objective?

Incubate samples containing 1.0 mL of ATP at 25C and determine the rate of transport for four other proteins.

Which statement best explains why correct protein folding is critical in the transmembrane protein shown above?

Interactions of the hydrophobic and hydrophilic amino acids help to anchor the protein in the membrane.

Which statement is the most accurate description of the reaction shown in Figure 1?

It represents a polypeptide chain that is broken down through a hydrolysis reaction.

Which of the following best predicts how the amino acid deletion will affect the structure of the CFTR protein?

It will affect the primary, secondary, and tertiary structures of the CFTRCFTR protein.

Which of the following observations best supports the model?

Mitochondria and some prokaryotes share similar metabolic reactions that produce ATPATP.

Which of the following outcomes will most likely result from a change in the shape of the mitochondrial inner membrane from a highly folded surface to a smooth, flat surface?

Mitochondria will become less efficient because the surface area of the inner mitochondrial membranes will decrease.

Which of the following statements best explains the processes of passive and active transport?

Passive transport is the net movement of substances down a concentration gradient that does not require metabolic energy.

Which of the following statements best describes how organisms such as rabbits obtain the carbon necessary for building biological molecules?

Rabbits eat plants and break down plant molecules to obtain carbon and other atoms that they rearrange into new carbon-containing molecules.

Which of the following statements best supports the claim that certain organelles within eukaryotic cells evolved from free-living prokaryotic cells?

Some organelles contain their own DNADNA that is more similar to prokaryotic DNADNA in structure and function than to the eukaryotic DNADNA found in the cell's nucleus.

Based on the model, the newly synthesized protein is transported directly from the endoplasmic reticulum to which of the following?

The Golgi complex

Which of the following statements best describes how molecules released by the fish become nutrients for the plants?

The ammonia molecules released by the fish are converted by the bacteria to nitrates, which are used by the plants to make proteins and nucleic acids.

Based on the information presented, which of the following is the most likely explanation for a buildup of cholesterol molecules in the blood of an animal?

The animal's body cells are defective in endocytosis.

Which of the following best describes a structural difference between DNA and RNA?

The backbone of DNADNA contains deoxyribose, whereas the backbone of RNARNA contains ribose.

Which of the following statements about glucose, galactose, and fructose is most likely true?

The carbohydrates have different properties because they have different arrangements of carbon, hydrogen, and oxygen atoms.

Which of the following best describes the effect of a greater number of cysteine amino acids on the stability of the proteins?

The change leads to increased protein stability because of an increased number of S-SS-S bonds in the tertiary structure of the proteins.

Which of the following, if true about the drug, best supports the alternative hypothesis that the new drug will exhibit simple diffusion across plasma membranes?

The drug is a small nonpolar molecule.

Which of the following is an accurate description of the process shown in Figure 1?

The formation of a covalent peptide bond in a dehydration synthesis reaction.

Which statement best explains the orientation of the phospholipid molecules in this model?

The hydrophilic phosphate groups of the phospholipid molecules are attracted to the aqueous internal and external environments.

Which of the following characteristics of Figure 1 best shows that the fragment is RNA and not DNA?

The identity of each nitrogenous base

Muscle cells have high ATP demands. Which of the following is a scientific claim about how the structure of the mitochondria in muscle cells should be different than it is in other cells because of the high energy demands of mitochondria?

The inner membrane of the mitochondria in muscle cells should have more folds to increase the surface area, allowing more ATP to be synthesized.

Which of the following outcomes will most likely result from a loss of ion pump function in the cell's lysosomes?

The internal pH of the lysosomes will increase, which will prevent the activation of hydrolytic enzymes and interfere with the intracellular digestion of food.

Which statement best helps explain the formation of the hydrogen bond represented in the figure?

The nitrogen has a partial negative charge, and the hydrogen attached to the oxygen has a partial positive charge.

Which of the following provides evidence to best support the researchers' claim?

The organelle has a double membrane.

Which of the following statements best explains the observations represented in Figure 1?

There was a net movement of water out of the cell suspended in the sugar solution and a net movement of water into the cell suspended in the distilled water.

Which of the following statements describes a feature shared by mitochondria and the endoplasmic reticulum that increases the efficiency of their basic functions?

They have highly folded membranes.

Which statement best describes the effect on water transport across the cell membrane if the aquaporin in the figure ceases to function?

Water molecules will still be able to move across the cell membrane but at a slower rate.