1.
Prokaryotic cells
Correct Answer
B. Contain ribosomes
Explanation
Prokaryotic cells contain ribosomes. Ribosomes are small structures within the cell that are responsible for protein synthesis. They are present in both prokaryotic and eukaryotic cells, but the structure and organization of ribosomes may differ between the two. In prokaryotic cells, ribosomes are smaller and less complex compared to eukaryotic cells. They play a crucial role in translating genetic information into proteins, which are essential for various cellular processes. Therefore, the statement "contain ribosomes" is a valid explanation for the given answer.
2.
Which of the following is not true regarding a plasma membrane?
Correct Answer
A. It is composed of two layers of pHospHolipids arranged with their hydropHilic ends pointing inwards.
Explanation
The plasma membrane is composed of two layers of phospholipids, but their hydrophilic ends are pointing outwards, not inwards. The hydrophilic heads of the phospholipids face the extracellular and intracellular fluid while the hydrophobic tails face each other in the middle of the membrane. This arrangement creates a selectively permeable barrier that regulates the movement of substances in and out of the cell.
3.
The purpose of photosynthesis is to
Correct Answer
B. Harness the sun’s energy to convert inorganic nutrients such as water and carbon dioxide into organic nutrients
Explanation
Photosynthesis is the process by which plants use the sun's energy to convert inorganic nutrients, such as water and carbon dioxide, into organic nutrients, specifically glucose. This glucose is then used as a source of energy for the cell. Therefore, the purpose of photosynthesis is to harness the sun's energy and convert inorganic nutrients into organic nutrients for the cell's energy needs.
4.
In eukaryotes, aerobic cellular respiration occurs in
Correct Answer
C. Mitochondria
Explanation
Mitochondria are the correct answer because they are the powerhouse of the cell and are responsible for aerobic cellular respiration in eukaryotes. They generate energy in the form of ATP through a series of biochemical reactions, including the citric acid cycle and oxidative phosphorylation. Ribosomes are responsible for protein synthesis, chloroplasts are found in plant cells and are responsible for photosynthesis, and lungs are organs found in animals that facilitate gas exchange. Therefore, none of these options are involved in aerobic cellular respiration.
5.
Which of the following statements is true regarding the comparison of aerobic cellular respiration and fermentation?
Correct Answer
B. Aerobic respiration is more efficient as it completely breaks down the glucose molecule and creates the maximum possible amount of ATP.
Explanation
Aerobic respiration is more efficient than fermentation because it fully breaks down the glucose molecule and produces the maximum amount of ATP. This is because aerobic respiration involves the complete oxidation of glucose in the presence of oxygen, which allows for the complete extraction of energy from the glucose molecule. In contrast, fermentation is an anaerobic process that only partially breaks down glucose, resulting in a lower yield of ATP. Therefore, aerobic respiration is the preferred method for organisms to generate energy when oxygen is available.
6.
The main component of a plasma membrane is
Correct Answer
C. Lipid
Explanation
The main component of a plasma membrane is lipid. Lipids, specifically phospholipids, form a bilayer structure in the plasma membrane, creating a barrier that separates the inside of the cell from the external environment. This lipid bilayer provides stability and flexibility to the membrane, allowing it to regulate the movement of molecules in and out of the cell. While proteins, carbohydrates, and cholesterol are also present in the plasma membrane, lipids are the primary component responsible for its structure and function.
7.
Chlorophyll can absorb some wavelengths of light more effectively than others. It can most effectively absorb light that is
Correct Answer
D. Blue
Explanation
Chlorophyll is the pigment responsible for absorbing light during photosynthesis. It absorbs light most effectively in the blue region of the electromagnetic spectrum. This is because chlorophyll molecules have a structure that allows them to capture and transfer energy from blue light photons. Green light is not absorbed as efficiently by chlorophyll, which is why plants appear green to our eyes. White and yellow light do not have specific wavelengths that chlorophyll can absorb more effectively.
8.
After this time, which test tube would you expect to have shown the most digestion?
Correct Answer
C. D because it has the same conditions as C but the protein has a higher surface area to volume ratio for more efficient enzyme action
9.
The Cell Theory was developed in the mid-1800s as a result of the work of Schwann, Schleiden and Virchow. Which of the following statements is NOT true of the Cell Theory?
Correct Answer
A. All living things are composed of groups of cells.
Explanation
The Cell Theory, developed in the mid-1800s, states that cells are the basic unit of life, new cells are produced from existing cells, and cells are organized structures. However, it is not true that all living things are composed of groups of cells. Some organisms, such as single-celled organisms, are composed of only one cell.
10.
A typical prokaryote cell is likely to demonstrate a
Correct Answer
B. Nucleus that is not membrane-bound
Explanation
A typical prokaryote cell is likely to demonstrate a nucleus that is not membrane-bound because prokaryotes are unicellular organisms that lack a true nucleus. Instead, their genetic material is located in a region called the nucleoid, which is not surrounded by a nuclear membrane. Prokaryotes are characterized by their simple internal structure, with no membrane-bound organelles like mitochondria or endoplasmic reticulum. They also have a single-stranded DNA molecule, in contrast to the double-stranded DNA found in eukaryotic cells.
11.
A sample of pond water contained many unicellular organisms, four of which are shown in the diagram. The pond water was placed in a glass beaker and supplied with nutrients over a period of 5 days. Which organism would be the most efficient (per unit volume per unit time) at absorbing nutrients?
Correct Answer
A. Organism Q
Explanation
Organism Q would be the most efficient at absorbing nutrients because it has the largest surface area to volume ratio among the four organisms. This means that it has a greater surface area available for nutrient absorption compared to its volume. As a result, Organism Q would be able to absorb nutrients more efficiently per unit volume and per unit time compared to the other organisms.
12.
A plasma membrane has the ability to allow the passage of some substances through it. The membrane is said to be
Correct Answer
C. Partially permeable
Explanation
A plasma membrane is selectively permeable, meaning it allows the passage of some substances while restricting others. It has specific channels and transport proteins that control the movement of molecules in and out of the cell. This property allows the cell to maintain its internal environment and selectively take in nutrients and eliminate waste products. Therefore, the correct answer is "partially permeable."
13.
Which organism would NOT contain this kind of structure?
Correct Answer
A. Animal
Explanation
Animals would not contain this kind of structure because animals are multicellular organisms that lack cell walls. In contrast, plants, algae, and protists are all capable of having cell walls.
14.
What is the most correct combination of various processes by which substances can cross cell membranes?
Correct Answer
B. Diffusion: Passive
Osmosis: movement of water from a region of low solute concentration to a region of high solute concentration
Active transport: occurs through a protein channel
Explanation
The correct combination of various processes by which substances can cross cell membranes is diffusion being passive, osmosis being the movement of water from a region of low solute concentration to a region of high solute concentration, and active transport occurring through a protein channel. Diffusion is the movement of a substance from a region of high to a region of low concentration, while osmosis is the movement of water. Active transport requires energy and occurs through a protein channel.
15.
In comparison to aerobic cellular respiration, fermentation
Correct Answer
C. Occurs in the absence of oxygen, produces less ATP and produces lactic acid in animals
Explanation
Fermentation occurs in the absence of oxygen, which is why it is also known as anaerobic respiration. It produces less ATP compared to aerobic cellular respiration because it does not go through the electron transport chain, which is the main source of ATP production in aerobic respiration. In animals, fermentation produces lactic acid as a byproduct, which can cause muscle fatigue and soreness.
16.
These structures are the site of an energy transformation process essential to living organisms. The process which occurs can be summarised as
Correct Answer
C. 6CO2 + 6H2O → C6H12O6 + 6O2
Explanation
The correct answer is 6CO2 + 6H2O → C6H12O6 + 6O2. This equation represents the process of photosynthesis, which occurs in the chloroplasts of plant cells. During photosynthesis, carbon dioxide (CO2) and water (H2O) are converted into glucose (C6H12O6) and oxygen (O2) using sunlight as the source of energy. This process is essential for living organisms as it produces glucose, which serves as a source of energy for cellular respiration and other metabolic processes. Additionally, photosynthesis also releases oxygen into the atmosphere, which is vital for the survival of many organisms.