1.
All of these organisms have a cell wall in their cells except for...?
Correct Answer
A. Animals
Explanation
Animals do not have a cell wall in their cells. Unlike plants, fungi, protists, and even some bacteria, animals have a cell membrane but lack a rigid cell wall. This allows for greater flexibility and movement in animal cells.
2.
Which of these features of the cell wall
allows water and solutes to easily move from the membrane?
Correct Answer
E. Both c and d
Explanation
Both options C and D, which are "semi-permeable" and "porous," allow water and solutes to easily move from the cell membrane. A semi-permeable cell wall allows only certain substances to pass through, while a porous cell wall has small openings that allow the movement of water and solutes. Both of these features contribute to the easy movement of water and solutes across the cell wall.
3.
This is the way that the cell membrane is able to allow material to pass in and out with energy.
Correct Answer
A. Active transport
Explanation
Active transport is the correct answer because it is the process by which cells move molecules across the cell membrane against their concentration gradient, requiring energy in the form of ATP. This allows the cell to control the movement of specific molecules in and out of the cell, even when the concentration gradient would naturally oppose their movement. This is in contrast to passive transport, diffusion, osmosis, and facilitated transport, which all rely on the concentration gradient and do not require energy.
4.
Which of these proteins help cells of the same type stick together in the proper tissues?
Correct Answer
D. Adhesion
Explanation
Adhesion proteins help cells of the same type stick together in the proper tissues. These proteins play a crucial role in maintaining the structural integrity of tissues and organs by promoting cell-cell adhesion. They form strong connections between adjacent cells, allowing them to adhere to each other and form stable tissue structures. Without adhesion proteins, cells would not be able to properly organize and function within tissues, leading to various developmental and physiological abnormalities.
5.
What is the most abundant component of the cell membrane?
Correct Answer
A. pHospHolipids
Explanation
Phospholipids are the most abundant component of the cell membrane. They are a type of lipid that forms a bilayer structure in the cell membrane, with the hydrophilic (water-loving) heads facing outward and the hydrophobic (water-fearing) tails facing inward. This arrangement provides a barrier that controls the movement of substances in and out of the cell. Phospholipids also play a crucial role in maintaining the fluidity and flexibility of the cell membrane. While carbohydrates, proteins, fats, and sterols are also present in the cell membrane, phospholipids make up the majority of its composition.
6.
Which of these allows for metabolic activity by separating the cell from the outside enviroment?
Correct Answer
C. Cell membrane
Explanation
The cell membrane is a selectively permeable barrier that separates the cell from its external environment. It allows for metabolic activity by controlling the movement of substances in and out of the cell. It regulates the entry and exit of molecules, ions, and nutrients, ensuring that the cell maintains a stable internal environment. The cell membrane also contains various proteins that play important roles in cell signaling, transport, and cell adhesion. Therefore, the cell membrane is essential for maintaining cellular homeostasis and allowing metabolic activity to occur within the cell.
7.
Which one of these features will allow it the cell to prevent from bursting from water pressure?
Correct Answer
A. Cell wall
Explanation
The cell wall is a rigid structure that surrounds the cell membrane in plant cells. It provides support and protection to the cell, preventing it from bursting due to water pressure. The cell wall is made up of cellulose, which is a strong and non-flexible material. It acts as a barrier, maintaining the shape and integrity of the cell even when there is high internal pressure. In contrast, the cell membrane, phospholipids, proteins, and adhesion proteins do not provide the same level of rigidity and strength as the cell wall, making them less effective in preventing the cell from bursting.
8.
Where is the secondary cell wall located?
Correct Answer
A. B/n plasma membrane and primary cell wall
Explanation
The secondary cell wall is located between the plasma membrane and the primary cell wall. This means that it is an additional layer that is formed inside the primary cell wall, providing extra support and protection to the plant cell. It is important to note that the secondary cell wall is specific to plant cells and is not found in animal cells.
9.
Which type of molecules in the cell wall are laid down in the gluey matrix of ropelike strands?
Correct Answer
C. Cellulose
Explanation
Cellulose molecules are laid down in the gluey matrix of ropelike strands in the cell wall. Cellulose is a type of polysaccharide that provides structural support to plant cells. It forms long chains of glucose molecules that are interconnected, creating a strong and rigid structure. The cellulose strands are embedded in a matrix of other molecules, forming a gluey substance that helps hold the cell wall together.
10.
What is the outermost layer of plant cells?
Correct Answer
C. Cell wall
Explanation
The outermost layer of plant cells is called the cell wall. This rigid structure provides support and protection to the cell, allowing it to maintain its shape and resist mechanical stress. The cell wall is composed of cellulose, a complex carbohydrate that forms a network of fibers, giving the cell wall its strength. It acts as a barrier, controlling the movement of substances in and out of the cell, and also plays a role in cell-to-cell communication and signaling.
11.
What aspect of the cell wall does not allow pathogens to enter it?
Correct Answer
B. Semi-permeable
Explanation
The aspect of the cell wall that does not allow pathogens to enter it is its semi-permeability. A semi-permeable membrane selectively allows certain substances to pass through while preventing others from entering. In the case of the cell wall, it acts as a barrier that only allows specific molecules and ions to pass through, while blocking the entry of pathogens and other harmful substances. This helps protect the cell and maintain its integrity.
12.
25% of the cell wall of woody plants are made out of what...?
Correct Answer
E. Lignin
Explanation
Lignin is a complex organic polymer that provides structural support to the cell walls of woody plants. It makes up about 25% of the cell wall composition in these plants. Lignin is a key component in the rigidity and strength of the cell walls, allowing them to withstand mechanical stress and provide support to the plant. It also helps in water transport and acts as a barrier against pathogens.
13.
What is a barrier to water-soluble substances?
Correct Answer
C. Lipid bilayer
Explanation
The lipid bilayer is a barrier to water-soluble substances because it is made up of hydrophobic fatty acid tails that repel water. This structure prevents water-soluble substances from freely diffusing across the membrane. Instead, these substances require specific channels or transport proteins to pass through the lipid bilayer.
14.
What is the difference between communication and receptor proteins?
Correct Answer
B. Communication proteins join heart muscle cells while receptor proteins change the cell activities.
Explanation
The given answer is incorrect. The correct answer is "Communication proteins send signals between the parts within the cell while the receptor proteins help identify each cell." This is because communication proteins are responsible for transmitting signals within the cell, allowing different parts of the cell to communicate with each other. On the other hand, receptor proteins are involved in identifying and binding to specific molecules or signals outside the cell, which then leads to changes in the cell's activities.
15.
What pumps specific solutes to the more concentrated side?
Correct Answer
A. Active transporters
Explanation
Active transporters are responsible for pumping specific solutes to the more concentrated side. Unlike passive transporters, which rely on the concentration gradient to move substances, active transporters require energy, usually in the form of ATP, to move solutes against their concentration gradient. This process allows cells to maintain a higher concentration of certain substances on one side of the membrane, which is essential for various cellular functions. The ER and the nucleus are not directly involved in solute transport, making them incorrect options.
16.
When identifying a cell, what does it mean for the cell to be "nonself"?
Correct Answer
D. Foreign to the body
Explanation
When a cell is described as "nonself," it means that the cell is foreign to the body. This suggests that the cell does not belong to the organism or is not a part of its normal functioning. It could be an invading pathogen or an abnormal cell that needs to be recognized and eliminated by the immune system. The term "nonself" is often used in the context of immunology to distinguish between the body's own cells (self) and external entities (nonself).
17.
In the lipid bilayer, what is the function of the hydrogen bonds?
Correct Answer
E. They help proteins associate with the pHospHolipids
Explanation
Hydrogen bonds in the lipid bilayer help proteins associate with the phospholipids. Proteins are embedded within the lipid bilayer and play a crucial role in various cellular processes. The hydrogen bonds between the proteins and phospholipids provide stability and facilitate their interaction. This association is important for the proper functioning of proteins and their involvement in cellular activities such as transport, signaling, and enzymatic reactions.
18.
What does mechanical strength do?
Correct Answer
E. A and C
Explanation
Mechanical strength in a cell wall refers to its ability to withstand external forces and maintain its structural integrity. It protects the cell wall by preventing it from breaking or collapsing under pressure. Additionally, mechanical strength also supports the cell wall by providing structural support and stability. Therefore, options A and C, which state that mechanical strength protects and supports the cell wall, are both correct.
19.
What is between the primary and secondary cell wall?
Correct Answer
B. Gluey pectin layer
Explanation
The gluey pectin layer is located between the primary and secondary cell walls. This layer acts as a cementing substance, holding the cell walls together and providing structural support to the cell. It is composed of pectin, a complex carbohydrate that is responsible for the gel-like consistency of the layer. The pectin layer helps to maintain the integrity and strength of the cell walls, allowing them to withstand mechanical stress and pressure.
20.
How are the cellulose molecules laid down?
Correct Answer
C. In gluey matrix of rope like strands
Explanation
Cellulose molecules are laid down in a gluey matrix of rope-like strands. This means that the molecules are arranged in a tangled and interconnected network, resembling the structure of ropes. This arrangement provides strength and rigidity to cellulose, making it a key component of plant cell walls.