in order from lower to upper the layers of the atmosphere are

HESI A2

HESI A2 Biology Practice Test

1. In order, from lower to upper, the layers of the atmosphere are:

A. Exosphere, thermosphere, mesosphere, stratosphere, troposphere
B. Troposphere, stratosphere, mesosphere, thermosphere, exosphere
C. Mesosphere, troposphere, stratosphere, thermosphere, exosphere
D. Thermosphere, troposphere, stratosphere, mesosphere, exosphere

Correct answer: B

Rationale: The correct order of the layers of the atmosphere, from lower to upper, is troposphere, stratosphere, mesosphere, thermosphere, exosphere. The troposphere is the lowest layer where weather phenomena occur. The stratosphere contains the ozone layer, which absorbs and scatters the solar ultraviolet radiation. The mesosphere is where most meteorites burn up upon entering the Earth's atmosphere. The thermosphere is characterized by high temperatures due to the absorption of solar radiation. The exosphere is the outermost layer where the atmosphere transitions into space. Therefore, option B is the correct sequence, as it reflects the ascending order of the Earth's atmospheric layers.

2. Two organisms live in a relationship from which both benefit. What is this called?

A. Mutualism
B. Parasitism
C. Commensalism
D. Competition

Correct answer: A

Rationale: Mutualism is a type of symbiotic relationship between two organisms in which both parties benefit from the association. It is a mutually beneficial interaction where both organisms gain something valuable, such as food, protection, or some other resource. This contrasts with parasitism, where one organism benefits at the expense of the other, commensalism, where one organism benefits while the other is unaffected, and competition, where both organisms are negatively affected by their interaction.

3. The procedure to focus an image using a compound microscope involves

A. Adjusting the coarse adjustment each time a new magnification is selected
B. Adjusting the fine adjustment each time a new magnification is selected
C. Adjusting the stage each time a new magnification is selected
D. All of the above

Correct answer: B

Rationale: When using a compound microscope, it is essential to adjust the fine adjustment knob each time you switch to a new magnification level. The fine adjustment knob allows for precise focusing on the specimen at different magnifications, ensuring a clear and sharp image. The coarse adjustment knob is typically used only at the lower magnification settings to bring the image into view roughly. Adjusting the stage may be necessary based on the size and thickness of the specimen, but it does not need to be done every time a new magnification is selected. Therefore, option B is the correct choice as it focuses on the key aspect of precise focusing during magnification changes.

4. Which organelle organizes protein synthesis?

A. mitochondrion
B. nucleus
C. ribosome
D. vacuole

Correct answer: C

Rationale: Ribosomes are the organelles responsible for organizing protein synthesis. They are the protein factories of the cell, where amino acids are linked together to form proteins. Mitochondria are known as the powerhouse of the cell, responsible for energy production. The nucleus contains the cell's genetic material but does not directly organize protein synthesis. Vacuoles are responsible for storage and maintaining the cell's turgidity.

5. Which organelle provides storage space for the cell?

A. Mitochondrion
B. Vacuole
C. Cell membrane
D. Ribosome

Correct answer: B

Rationale: The correct answer is B: Vacuole. The vacuole is the organelle responsible for providing storage space in the cell. It stores water, nutrients, waste products, and other essential materials required by the cell. Vacuoles are crucial for maintaining cell structure and regulating cellular processes. Mitochondrion (choice A) is known as the powerhouse of the cell, responsible for producing energy. The cell membrane (choice C) is a protective barrier around the cell, regulating what enters and exits the cell. Ribosomes (choice D) are involved in protein synthesis, not storage.