the force per unit area exerted against a surface by the weight of air above that surface in the earths atmosphere is the

HESI A2

Biology HESI A2 Practice Test

1. The force per unit area exerted against a surface by the weight of air above that surface in the Earth's atmosphere is the ______.

A. Atmospheric pressure
B. Barometric density
C. Aneroid pressure
D. Barometric pressure

Correct answer: A

Rationale: Atmospheric pressure is the correct term for the force per unit area exerted against a surface by the weight of air above that surface in the Earth's atmosphere. It is commonly measured in units such as pascals, millibars, or inches of mercury. Barometric density and aneroid pressure are not accurate descriptions for this phenomenon. Barometric density refers to the density of the atmosphere at a particular location, while aneroid pressure is linked to a type of barometer but not a comprehensive term for the force exerted by the weight of air.

2. Why are bacteria and blue-green algae often classified together?

A. Both are gymnosperms.
B. Both are prokaryotes.
C. Both are autotrophs.
D. Both are pathogens.

Correct answer: B

Rationale: Bacteria and blue-green algae (cyanobacteria) are often classified together because they are both prokaryotes. Prokaryotes are unicellular organisms that lack a membrane-bound nucleus and other membrane-bound organelles. This characteristic distinguishes them from eukaryotic organisms, which have these membrane-bound structures. Choice A is incorrect because gymnosperms are seed-producing plants with naked seeds, not bacteria or blue-green algae. Choice C is incorrect because being an autotroph (able to produce its own food) is not a reason for classifying them together. Choice D is incorrect because not all bacteria and blue-green algae are pathogens; many of them are beneficial or neutral to other organisms.

3. Which of these is not an example of a lipid?

A. Butter
B. Wax
C. Canola oil
D. Honey

Correct answer: D

Rationale: Honey is not an example of a lipid because lipids are fat-related molecules that are insoluble in water, while honey is a natural sweet substance made by bees and primarily consists of sugars such as glucose and fructose. Butter, wax, and canola oil are examples of lipids as they are all composed of fat-related molecules that do not dissolve in water.

4. Which of the following is true of heterozygous traits?

A. They are haploid
B. They are denoted AA
C. They are denoted aa
D. They are denoted Aa

Correct answer: D

Rationale: Heterozygous traits are denoted by having two different alleles for a particular gene, represented as Aa. This means that they are not haploid (A), not denoted AA (B), and not denoted aa (C). Therefore, the correct answer is D, as heterozygous traits are represented as Aa.

5. Which of the following organisms would not have eukaryotic cells?

A. Bacteria
B. Dog
C. Human
D. Onion

Correct answer: A

Rationale: The correct answer is A, Bacteria. Bacteria do not have eukaryotic cells. They are single-celled organisms with prokaryotic cells. Dogs, humans, and onions are all multicellular organisms that possess eukaryotic cells. Therefore, choices B, C, and D have eukaryotic cells and are not the correct answer.