a scientist needs 12 ml of a solution they have a bottle with 12l in it do they have enough

HESI A2

Biology HESI A2 Practice Test

1. A scientist needs 12 mL of a solution. They have a bottle with 12L in it. Do they have enough?

A. Yes, they have exactly what they need
B. Yes, they have more than what they need
C. No, they do not have enough
D. None of the above

Correct answer: B

Rationale: 1 liter has 1000 milliliters. To convert from milliliters to liters, the decimal point moves three places to the left. So, the bottle has 12000 mL of solution, which is a lot more than the required 12 mL. Therefore, the scientist has more than what they need. Choice A is incorrect as the bottle has more than the required amount. Choice C is incorrect as the bottle contains significantly more solution than needed. Choice D is incorrect as the scientist does have more than enough solution.

2. Beeswax is an example of what kind of molecule?

A. Lipid
B. Carbohydrate
C. Protein
D. Nucleic acid

Correct answer: A

Rationale: Beeswax is primarily composed of esters of long-chain aliphatic alcohols and fatty acids, making it a type of lipid. Lipids are a diverse group of molecules that are hydrophobic in nature and have important functions in energy storage, signaling, and forming cellular membranes. Beeswax's chemical composition and properties categorize it as a lipid rather than a carbohydrate, protein, or nucleic acid. Carbohydrates are composed of sugars, proteins are made up of amino acids, and nucleic acids consist of nucleotides; none of which match the chemical composition of beeswax.

3. Which one of the following best describes the function of a cell membrane?

A. It controls the substances entering and leaving the cell.
B. It maintains the cell's shape.
C. It controls the substances entering the cell.
D. It supports the cell's structures.

Correct answer: A

Rationale: The correct answer is A. The function of a cell membrane is to control the substances entering and leaving the cell. The cell membrane is selectively permeable, allowing it to regulate the movement of ions and molecules in and out of the cell to maintain internal balance and proper function. Choice B is incorrect because while the cell membrane does provide some structural support, its primary function is not to maintain the cell's shape. Choice C is incorrect because the cell membrane controls both the substances entering and leaving the cell, not just those entering. Choice D is incorrect as the primary function of the cell membrane is not to support the cell's structures but to regulate the movement of substances.

4. What event occurs during telophase?

A. The nuclear envelope disappears.
B. Organelles double in number.
C. Chromosomes separate.
D. Two nuclei are formed.

Correct answer: D

Rationale: During telophase, the final stage of mitosis, the separated chromosomes reach opposite poles of the cell. At this stage, a new nuclear envelope forms around each set of chromosomes, creating two distinct nuclei. This marks the completion of cell division. Choices A, B, and C are incorrect because the disappearance of the nuclear envelope typically occurs during prophase, organelles do not double in number during telophase, and chromosomes separate during anaphase, not telophase.

5. Which form of fermentation is used to produce beer?

A. Lactic acid fermentation
B. Acetic acid fermentation
C. Propionic acid fermentation
D. Ethyl alcohol fermentation

Correct answer: D

Rationale: The correct answer is D, Ethyl alcohol fermentation. During beer production, yeast metabolizes sugars in the wort to produce ethanol (ethyl alcohol) and carbon dioxide, which are responsible for the alcohol content and carbonation in beer. Choices A, B, and C are incorrect because lactic acid fermentation produces lactic acid, acetic acid fermentation produces acetic acid, and propionic acid fermentation produces propionic acid, none of which are used in the production of beer.