Question 1

At the most basic level of life, organic compounds are organized into energy-dependent, self-replicating units known as ____________________.

Accepted Answer

The answer of At the most basic level of life,...

Question 2

The membrane known as the _____ contains light-capturing pigments like chlorophyll.

Accepted Answer

The thylakoid membrane is where the light-capturing pigments like chlorophyll are located in plant cells. The other options, the pore, envelope, and crista, do not play a role in light absorption in photosynthesis.

Question 3

The ____________________includes the entire contents of a cell except for the nucleus.

Accepted Answer

The answer of The ____________________includes the entire contents of a...

Question 4

Which of the following statements is false?

Accepted Answer

Actin filaments are responsible for many cellular functions including movement, shape change, and cell division, but they do not define paths for vesicle movement within the cell. Microtubules and intermediate filaments are more involved in vesicle transport.

Question 5

Protists use cilia to move within their habitat, but ciliated human cells like those in the bronchi are always anchored to one another and to an extracellular matrix; what benefit does cilia provide these cells?

Accepted Answer

Ciliary movement in human cells, such as those in the bronchi, helps move mucus and trapped particles out of the respiratory tract, aiding in keeping the airways clear.

Question 6

Which of the following is correctly matched?

Accepted Answer

Flagella are composed of microtubules made of the protein tubulin. Cilia, on the other hand, are also made of microtubules but have a slightly different composition and structure compared to flagella. Pseudopodia are not associated with intermediate filaments, but rather with actin microfilaments. Keratin is a type of intermediate filament found in epithelial cells, but it is not associated with microfilaments.

Question 7

The protist that causes malaria, Plasmodium falciparum, is unusual in that it is an intracellular parasite. Most parasites are too large to enter cells. How does P. falciparum accomplish its entry?

Accepted Answer

P. falciparum inserts a pore into the cell membrane and later uses the pore as an entry portal.

Question 8

Which of the following components contribute to the structure of the cytoskeleton of a cell?

Accepted Answer

Microtubules and actin filaments are the two major components that contribute to the structure of the cytoskeleton in cells. Pseudopodia and motor proteins are involved in cell movement, but not necessarily in the cytoskeleton. Chloroplasts and mitochondria are organelles within cells that have their own specific functions, but do not contribute to cytoskeletal structure. The cell wall and plasma membrane are external structures that provide protection and support, but are not part of the cytoskeleton inside the cell.

Question 9

Which of the following statements about mitochondria and chloroplasts is false?

Accepted Answer

Mitochondria and chloroplasts are believed to have originated from free-living prokaryotic cells through endosymbiosis, not from primitive eukaryotic cells.

Question 10

Membrane-enclosed structures in eukaryotic cells are called ____________________.

Accepted Answer

The answer of Membrane-enclosed structures in eukaryotic cells are called...

Question 11

The cell in the figure below is moving by producing pseudopodia. This type of movement is a result of the reorganization of a certain component of the cytoskeleton (labeled). 
The various labeled lines in the figure above show

Accepted Answer

The pseudopodia movement in the figure is a result of the disassembly of microfilaments at the trailing edge of the movement. Microfilaments play a key role in cell motility through the generation of force and oriented movement.

Question 12

Biologists call an agent that spreads an infectious disease a vector. What is the vector for malaria?

Accepted Answer

The vector for malaria is a mosquito of the species Anopheles, which carries the Plasmodium protist responsible for causing the disease.

Question 13

Which of the following works like a propeller?

Accepted Answer

The prokaryotic flagella work like a propeller, rotating to drive the cell forward. The eukaryotic flagella and cilia move with a whip-like motion, and the prokaryotic cilia do not exist, as only eukaryotic cells have true cilia.

Question 14

Microtubules are responsible for

Accepted Answer

Microtubules are a component of the cytoskeleton and are responsible for facilitating intracellular transport, including the movement and positioning of organelles within the cell. They do not play a role in the formation of pseudopodia or skin cell strengthening, and while they do help to reinforce and support cell structure, this is not their primary function.

Question 15

Organisms whose cells lack internal membrane-bound organelles are classified as ____________________.

Accepted Answer

The answer of Organisms whose cells lack internal membrane-bound organelles...

Question 16

The ____________________ model describes the plasma membrane as a mobile mixture of phospholipids and proteins.

Accepted Answer

The answer of The ____________________ model describes the plasma membrane...

Question 17

Certain ____________________ in a cell's membrane form channels through which ions and molecules may pass.

Accepted Answer

The answer of Certain ____________________ in a cell's membrane form...

Question 18

The contents of cells are often visualized with fluorescent (glow-in-the-dark)stains. You treat a cell with a stain that makes a certain part of the cytoskeleton glow green and another stain that makes mitochondria glow red. Under the microscope you see a meshwork of green filaments throughout the cell. Red organelles appear to be traveling along the filaments. The green stain you used must stain

Accepted Answer

Microtubules are the largest cytoskeletal filaments and are known to be important for intracellular transport. Motor proteins, such as kinesin and dynein, can move organelles along microtubules. The green stain in this scenario is most likely staining microtubules and the red stain is most likely staining mitochondria that are being transported along these filaments.

Question 19

Chemical reactions occur more efficiently in ____________________ because their reactants are concentrated within a specialized compartment.

Accepted Answer

The answer of Chemical reactions occur more efficiently in ____________________...

Question 20

The figure below shows a mitochondrion, emphasizing its inner and outer membranes. 
The inner membrane of the mitochondria is thought to have evolved from

Accepted Answer

The inner membrane of the mitochondria is thought to have evolved from the plasma membrane of a prokaryotic cell that was engulfed by an early eukaryotic cell. This theory is known as the endosymbiotic theory and suggests that mitochondria were once free-living bacteria that were engulfed by an ancient eukaryotic cell. Over time, these bacteria evolved into mitochondria, and their outer membrane fused with the plasma membrane of the host cell while their inner membrane retained its bacterial characteristics.

Quiz 6: Cell Structure and Internal Compartments