1.
All members of which biological group require a host cell to reproduce?
Correct Answer
D. Viruses
Explanation
Viruses require a host cell to reproduce. Unlike other biological groups, viruses are not considered living organisms as they lack the ability to reproduce on their own. Instead, they invade host cells and take over their machinery to replicate themselves. This dependence on a host cell is what distinguishes viruses from other groups such as fungi, bacteria, and protists, which can reproduce independently.
2.
Which statement best explains how penicillin, a common antibiotic, stops the growth of certain bacteria?
Correct Answer
C. It inhibits synthesis of bacterial walls.
Explanation
Penicillin, a common antibiotic, stops the growth of certain bacteria by inhibiting the synthesis of bacterial walls. Bacterial walls are essential for maintaining the structural integrity and protection of bacteria. Penicillin interferes with the process of bacterial cell wall synthesis, specifically by inhibiting the formation of peptidoglycan, a key component of the bacterial cell wall. This disruption weakens the bacterial cell wall, making it more susceptible to damage and ultimately leading to the death of the bacteria.
3.
Alec studied an unknown microscopic organism and recorded this information:- It contains DNA.- It has a cell wall, but no nucleus.What is Alec most likely studying?
Correct Answer
A. Bacterium
Explanation
Based on the information provided, Alec is most likely studying a bacterium. Bacteria are microscopic organisms that have DNA and a cell wall, but they lack a nucleus. Fungi, protists, and viruses do not fit all the characteristics mentioned, making bacterium the most suitable option.
4.
Bacterial cells
Correct Answer
C. Have both a cell membrane and cell wall.
Explanation
Bacterial cells have both a cell membrane and cell wall. The cell membrane is a thin, flexible barrier that surrounds the cytoplasm and controls the movement of substances in and out of the cell. The cell wall, on the other hand, is a rigid structure located outside the cell membrane that provides support and protection to the cell. It helps maintain the shape of the cell and prevents it from bursting under osmotic pressure. Therefore, bacterial cells possess both a cell membrane and cell wall to ensure their structural integrity and functionality.
5.
Structures found in a eukaryotic cell but not in a bacterial (prokaryotic) cell are
Correct Answer
D. All of the answers
Explanation
The correct answer is "All of the answers." This is because eukaryotic cells, unlike bacterial cells, have cell nuclei, multiple chromosomes, and membrane-bound organelles. These structures are unique to eukaryotic cells and play important roles in their functions and organization.
6.
One difference between human body cells and bacterial cells is that bacterial cells have
Correct Answer
B. A cell wall.
Explanation
Bacterial cells have a cell wall, which is a rigid structure that surrounds the cell membrane. This cell wall provides support and protection to the bacterial cell. In contrast, human body cells do not have a cell wall. They have a flexible cell membrane that surrounds the cell. The presence of a cell wall is one of the key differences between bacterial cells and human body cells.
7.
Bacteria lack a true nucleus and membrane-bound organelles; therefore, they are classified as
Correct Answer
A. Prokaryotes.
Explanation
Bacteria lack a true nucleus and membrane-bound organelles, which are defining characteristics of eukaryotes. Instead, they have a single circular chromosome and their genetic material is located in the cytoplasm. This lack of a nucleus and membrane-bound organelles classifies bacteria as prokaryotes.
8.
A hospital patient had a serious bacterial infection that required treatment with strong antibiotics. The patient recovered from the infection, but experienced side effects, including oral fungal infections and digestive problems. What is the most probable reason for the side effects?
Correct Answer
C. The antibiotics killed both harmful and beneficial bacteria.
Explanation
The most probable reason for the side effects is that the antibiotics killed both harmful and beneficial bacteria. Antibiotics are designed to kill bacteria, but they can also kill the beneficial bacteria in the body that help with digestion and maintaining a healthy balance. This can lead to oral fungal infections and digestive problems as the body's natural balance is disrupted.
9.
Which group(s) contain organisms that can be classified as primary producers?
Correct Answer
C. Bacteria and protists
Explanation
Bacteria and protists can be classified as primary producers because they have the ability to produce their own food through photosynthesis or chemosynthesis. Bacteria can perform photosynthesis using light energy, while protists can perform photosynthesis or obtain energy from inorganic compounds. Both groups play a crucial role in the food chain by converting energy from the sun or inorganic compounds into organic matter, which is then consumed by other organisms.
10.
Which of the following might be found in the cytoplasm of a bacterial cell?
Correct Answer
D. None of the answers
Explanation
Bacterial cells are prokaryotic cells, which means they lack membrane-bound organelles like chloroplasts, Golgi apparatus, and mitochondria. These organelles are found in eukaryotic cells, not in bacterial cells. Therefore, none of the given options are correct.