Question 1

Water is moving across a membrane from solution A into solution B.What can you infer?

Accepted Answer

The answer of Water is moving across a membrane from...

Question 2

According to the cell theory,all cells come from

Accepted Answer

The cell theory states that all cells arise from pre-existing cells, meaning that they come from previously existing cells through cell division. This is a fundamental principle of biology and is supported by numerous observations and experiments. Choice A, adaptation, refers to a process by which organisms change over time in response to selective pressures, but it is not directly related to the origin of cells. Choice B, a common ancestor, is related to evolution and the idea that all life on Earth shares a common ancestry, but again, it is not directly related to the origin of cells. Choice D refers to a hypothetical precursor to modern cells, and choice E refers to a specific type of symbiosis that explains the origin of eukaryotic cells, but neither of these is directly related to the idea that all cells come from pre-existing cells.

Question 3

Which of the following is/are associated with eukaryotic cells but not with prokaryotic cells?

Accepted Answer

Only eukaryotic cells have a distinct nucleus that contains genetic material separated from the cytoplasm by a nuclear envelope. Prokaryotic cells have their genetic material dispersed in the cytoplasm. The other options (A, B, C, and D) are all found in both prokaryotes and eukaryotes, although they may be slightly different in composition or structure.

Question 4

Which organelle would cause the most damage to cytoskeletal fibers in the cytoplasm if its contents were to leak into the cytoplasm?

Accepted Answer

Lysosomes contain digestive enzymes that can break down various biomolecules, including cytoskeletal fibers, when released into the cytoplasm. Therefore, the leakage of lysosomal enzymes into the cytoplasm can cause the most damage to the cytoskeletal fibers in the cytoplasm.

Question 5

Which of the following statements best explains why bacteria are considered living organisms?

Accepted Answer

The defining characteristic of living organisms is that they consist of cells. Bacteria are unicellular, meaning each individual bacterium consists of a single cell, which is why they are considered living organisms. The other options (A, B, C, and E) are not specific to living organisms and can apply to non-living things as well.

Question 6

Sugars are large,hydrophilic molecules that are important energy sources for cells.How can they enter cells from an environment with a very high concentration of sugar?

Accepted Answer

Sugars are hydrophilic molecules, which means they cannot pass through the hydrophobic layer of the plasma membrane without assistance. Facilitated diffusion is the process of passive transport of these large molecules across the membrane through a protein channel or carrier protein. This allows the sugars to move down their concentration gradient from an area of high concentration outside the cell to an area of low concentration inside the cell.

Question 7

Which feature is found in eukaryotic cells but not in prokaryotic cells?

Accepted Answer

Eukaryotic cells have a nucleus, where the genetic information is stored and protected by a nuclear membrane. Prokaryotic cells do not have a nucleus and their DNA is located in the cytoplasm. The other features (cytoplasm, cell membrane, DNA, ribosomes) are found in both prokaryotic and eukaryotic cells.

Question 8

According to the cell theory,all living organisms are composed of

Accepted Answer

The cell theory states that all living organisms are composed of one or more cells, making option B the correct choice. While all living organisms contain DNA and proteins, not all of them are composed of them exclusively. Option D, macromolecules, also does not accurately describe the composition of all living organisms. Option E, phospholipids, is only a component of cell membranes and not necessarily present in all living organisms.

Question 9

Insulin is a protein hormone secreted by certain pancreatic cells into the bloodstream.Which of the following organelles are involved in the synthesis and secretion of insulin?

Accepted Answer

Insulin synthesis involves ribosomes for protein synthesis, the rough ER for folding and initial modifications, and the Golgi apparatus for further modifications and packaging into secretory vesicles.

Question 10

If a solute is moving through a phospholipid bilayer from an area of higher concentration to an area of lower concentration without the assistance of a protein,the manner of transport must be

Accepted Answer

If a solute is moving through a phospholipid bilayer from an area of higher concentration to an area of lower concentration without the assistance of a protein, it means that the solute is moving down its concentration gradient. This type of passive transport is known as simple diffusion.

Question 11

Which of the following is/are not associated with human cells?

Accepted Answer

Cell walls are not associated with human cells. They are found in plant cells, fungi, and some bacteria.

Question 12

Bacteria are _____ cells,defined by the _____.

Accepted Answer

Bacteria are prokaryotic cells, meaning they do not have a nucleus or membrane-bound organelles. They also do not have a defined nucleus or other membrane-bound structures surrounding their genetic material. Therefore, they are classified as prokaryotic. The presence or absence of a cell wall is also a defining characteristic of bacterial cells, but it is not specific enough to use as the only criterion for determining their classification.

Question 13

According to the cell theory,which of the following is NOT considered a living organism?

Accepted Answer

According to the cell theory, living organisms are composed of one or more cells. However, viruses are not considered living organisms as they cannot reproduce or carry out metabolic processes without a host cell.

Question 14

The two major components of cell membranes are _____ and _____.

Accepted Answer

Phospholipids are the primary component of cell membranes, forming a bilayer with hydrophobic tails facing inward and hydrophilic heads facing outward. However, proteins are also important components of cell membranes, often serving as channels, receptors, and enzymes. The other answer choices are incorrect because DNA is not a component of cell membranes, and peptidoglycan is only found in bacterial cell walls, not in other types of cells.

Question 15

Which of the following combinations INCORRECTLY matches an organelle with its function?

Accepted Answer

Lysosomes are responsible for breaking down waste materials and old cell components, not internal support or movement.

Question 16

Penicillin interferes with the synthesis of _____.

Accepted Answer

Penicillin interferes with the synthesis of peptidoglycan, which is an essential component of bacterial cell walls. This weakens the cell wall and ultimately leads to bacterial cell death.

Question 17

Some inherited syndromes,for example MERRF (myoclonic epilepsy with ragged red fibers),interfere with the function of mitochondria.From what you know about mitochondria,why do you think the muscles and the nervous system are the predominant tissues affected in MERRF?

Accepted Answer

Mitochondria are responsible for producing ATP, the energy currency of the cell, through aerobic respiration. The muscles and nervous system are the most metabolically active tissues in the body and require a lot of energy to function properly, making them more susceptible to dysfunction when mitochondrial function is compromised.

Question 18

Which of the following is not a cytoskeletal fiber in eukaryotic cells?

Accepted Answer

There is no such thing as macrotubules in eukaryotic cells. The other options are all types of cytoskeletal fibers.

Question 19

The "endosymbiotic hypothesis" is a concept that explains _____.

Accepted Answer

The endosymbiotic hypothesis proposes that eukaryotic cells evolved by incorporating bacteria-like cells that eventually became mitochondria and chloroplasts, explaining how these organelles came to be present in eukaryotic cells.

Question 20

Which of the following is NOT a cytoskeletal fiber in eukaryotic cells?

Accepted Answer

The answer of Which of the following is NOT a...

Quiz 3: Cell Structure and Function