高中生物: Understanding Specialized Cell Structures

Study concepts, example questions & explanations for High School Biology

varsity tutors app store varsity tutors android store

Example Questions

Example Question #1 :Cellular Differences

The shape of an animal cell is determined by which of the following?

Possible Answers:

Plasma membrane

None of these answers

Cholesterol

Cell wall

Cytoskeleton

Correct answer:

Cytoskeleton

Explanation:

The cytoskeletion determines cell shape. The cytoskeleton consists of three different types of filamentous proteins: microfilaments, intermediate filaments, and microtubules. Elements of the cytoskeleton can interact with the cell membrane and cell junctions to alter the cell's overall structure.

There are no cell walls in animal cells, although the cell wall does play a large part in determining cell shape in organisms that possess them (plants, bacteria, fungi).

Example Question #81 :Cell Structures And Organelles

Which organelle works to synthesize an unstable form of energy?

Possible Answers:

Rough endoplasmic reticulum

Mitochondria

Two of the other answer choices are correct.

None of the other answer choices is correct.

Chloroplast

Correct answer:

Two of the other answer choices are correct.

Explanation:

The unstable form of energy that is syntheisized refers to ATP. ATP is an unstable; its three phosphate groups are all negatively charged and repel one another. Remember that BOTH the mitochondria and chloroplast participate in ATP synthesis via chemiosmosis; however, only the chloroplast participates in glucose synthesis via photosynthesis. Note that glucose is a stable form of energy and is not readily usable until it is broken down in the process known as glycolysis.

Example Question #1 :Cellular Differences

The nucleolus__________.

Possible Answers:

is found in prokaryotes and eukaryotes

contains all the DNA of the cell

is only found in prokaryotes

None of the other answer choices is true.

is a part of the nucleus responsible for assembling ribosomes

Correct answer:

is a part of the nucleus responsible for assembling ribosomes

Explanation:

The nucleolus is a subdivision of the nucleus; thus, it is only found in eukaryotes. It is the site of ribosome assembly. The nucleolus is made of RNA and proteins.

Example Question #1 :Cellular Differences

Histones__________.

Possible Answers:

are only found in eukaryotic cells

are protiens around which DNA coils

play a role in gene regulation

All of the answer choices are true.

are only found in the nucleus

Correct answer:

All of the answer choices are true.

Explanation:

Histones are proteins found in the nucleus of eukaryotic cells. DNA wraps itself around histones to further condense. Also, depending on how tightly the DNA is wrapped around the histones, it may or may not be availible for activity (e.g. replication or transcription). Cells modify the interaction between DNA and histones around certain genes under certain conditions to make those genes available or unavailable as needed.

Example Question #661 :Cellular Biology

In which of the following organisms are vacuoles not usually found?

Possible Answers:

Plants

Fungi

Bacteria

Mammals

Correct answer:

Mammals

Explanation:

Vacuoles are membrane-bound structures that are found in bacterial, plant, fungal, and occasionally, animal cells. Vacuoles function in storage of water and waste and in maintenance of turgor pressure in plants.

Learning Tools by Varsity Tutors