Question 1

An important by-product of photosynthesis is:

Accepted Answer

Oxygen is produced as a by-product of photosynthesis. Carbon dioxide and water are used as raw materials in photosynthesis, and their energy is harnessed to produce glucose, but oxygen is released as a waste product.

Question 2

What maintains cell shape, anchors organelles in place, and moves materials within a cell?

Accepted Answer

The cytoskeleton is a network of protein fibers that maintains cell shape, anchors organelles in place, and moves materials within a cell.

Question 3

Mitochondria and chloroplasts are similar to one another in that both:

Accepted Answer

Both mitochondria and chloroplasts have their own DNA and ribosomes. Mitochondria have circular DNA and ribosomes similar to prokaryotic cells, while chloroplasts have their own DNA and ribosomes that are similar to bacterial DNA and ribosomes.

Question 4

The most common form of cystic fibrosis, a fatal genetic disease, occurs when a protein destined for the plasma membrane of the cell is destroyed. The protein is destroyed by one of the cell's organelles because the protein is not shaped correctly. Which organelle recognizes the misshaped protein?

Accepted Answer

The rough endoplasmic reticulum is responsible for protein synthesis and folding. If a protein is misshaped, it will not be able to leave the rough endoplasmic reticulum and will be degraded within the organelle. This is likely the cause of the most common form of cystic fibrosis.

Question 5

People with oxidative phosphorylation disorders suffer a lack of energy that can lead to diminished function of nerve and muscle cells. The organelle most likely to be altered in oxidative phosphorylation disorders is the:

Accepted Answer

Oxidative phosphorylation occurs in the mitochondria, and therefore any disorders related to this process are likely to affect this organelle.

Question 6

Which of the following are associated with energy transfer in eukaryotic cells?

Accepted Answer

Chloroplasts and mitochondria are both organelles involved in energy transfer in eukaryotic cells. Chloroplasts convert light energy into chemical energy through photosynthesis, while mitochondria convert organic compounds into ATP through cellular respiration. Rough ER, smooth ER, lysosomes, Golgi complex, and cell wall are not directly involved in energy transfer.

Question 7

Which organelles are believed to have originated from free-standing bacteria ingested by ancient eukaryotic cells?

Accepted Answer

Mitochondria and chloroplasts are believed to have evolved from ancient free-standing bacteria that were engulfed by early eukaryotic cells through endosymbiosis. This is supported by the fact that both organelles have their own DNA and replicate independently from the cell.

Question 8

You owe your life to chloroplasts. The reason for this is that:

Accepted Answer

Chloroplasts are responsible for producing the oxygen we breathe, as well as being the source of nutrients in the form of carbohydrates, lipids, and proteins that we consume from plant-based foods. They use photosynthesis to convert carbon dioxide and water into glucose, releasing oxygen as a byproduct. Without chloroplasts, life on Earth as we know it would not be possible.

Question 9

Which of the following pairs is correctly matched?

Accepted Answer

Microtubules are made up of the protein tubulin, while intermediate filaments and microfilaments are made up of different proteins. The endomembrane system also has no relation to cilia.

Question 10

Tay-Sachs disease results from the accumulation of fatty deposits within neurons, when normally they should be broken down within these cells. The organelle that would be defective in Tay-Sachs would most likely be the:

Accepted Answer

Tay-Sachs disease is a lysosomal storage disorder. The organelle that is defective in Tay-Sachs is the lysosome, which is supposed to break down fatty deposits within neurons.

Question 11

The large central vacuole of plants:

Accepted Answer

The large central vacuole of plants may make up as much as 90 percent of the internal volume of the cell. This is because the vacuole is responsible for storing water, ions, and other nutrients, and can expand or contract to maintain turgor pressure in the cell.

Question 12

Which of the following would you find in a plant cell but not an animal cell?

Accepted Answer

A central vacuole is a large, membrane-bound organelle found in plant cells that functions in storage of water, ions, and nutrients, as well as contributing to maintaining turgor pressure within the cell. Animal cells typically have multiple small vacuoles, if any at all, and do not have a central vacuole. Lysosomes and mitochondria are found in both plant and animal cells, while microtubules are a component of the cytoskeleton found in both cell types.

Question 13

The cytoskeleton is composed of:

Accepted Answer

The cytoskeleton is composed of microfilaments (also known as actin filaments), intermediate filaments, and microtubules. Cilia and lysosomes are not part of the cytoskeleton, and mitochondria are organelles that are not involved in cytoskeleton structure.

Question 14

Microfilaments:

Accepted Answer

Microfilaments are involved in cell movement and can help cells capture prey, such as in the case of amoeboid movement. Microtubules, not microfilaments, play a role in stabilizing the position of the nucleus, acting as monorails for organelle movement, and forming the structure of cilia and flagella.

Question 15

Cell walls can be found as part of:

Accepted Answer

Cell walls are found in plant cells, bacteria, fungi, and some protists. They are not found in animal cells. Therefore, option B is the correct answer.

Question 16

Animal cells need oxygen most directly to:

Accepted Answer

Oxygen is required by animal cells to undergo cellular respiration, which produces ATP, the energy currency of the cell. While oxygen may indirectly contribute to the production of enzymes, DNA, and proteins, these processes do not directly require oxygen.

Question 17

The 1992 film Lorenzo's Oil told the true story of Lorenzo Odone who suffered from the disease adrenoleukodystrophy. This disease affected an organelle in his cells called a peroxisome. The peroxisome lacked an enzyme that controls the breakdown of a long chain fatty acid that resulted in a buildup of the fatty acid in his brain and spinal cord. The function of peroxisomes must be similar to the function of what other organelle?

Accepted Answer

Peroxisomes and lysosomes share similar functions in breaking down molecules and removing waste in cells. While peroxisomes specialize in breaking down fatty acids, lysosomes break down a variety of materials including proteins, carbohydrates, and lipids. However, both organelles play a vital role in maintaining cellular health and function.

Question 18

Smoker's cough results from damage to the external structure of lung cells by tobacco smoke. What part of the cell would you predict is damaged?

Accepted Answer

Cilia are hair-like structures on the surface of cells that help move mucus and other substances out of the respiratory tract. Tobacco smoke damages and paralyzes cilia in the airways, resulting in a build-up of mucus and a smoker's cough.

Question 19

Eukaryotic cilia and flagella:

Accepted Answer

Both cilia and flagella in eukaryotic cells have a structure made up of microtubules, called the axoneme, which is responsible for their movement. Choices A and B are incorrect as cilia and flagella are also found in multicellular organisms, and their functions are not limited to sweeping the lungs. Choice C is incorrect as the number of cilia and flagella on the cell surface varies across different cell types. Choice E is partially correct, as cilia and flagella can indeed act as receptors, but this is not their primary function.

Question 20

Both cilia and flagella are involved in which of the following functions?

Accepted Answer

Both cilia and flagella are involved in the movement of cells or movement of material around a cell.

Quiz 4: Lifes Home: the Cell