Free STEMscopes Life Science Questions and Answers — Questions and Answers
Question 1: What is the primary function of the cell membrane?
- Control cellular reproduction
- Regulate what enters and leaves the cell (Correct answer)
- Produce energy for the cell
- Store genetic information
Correct answer: Regulate what enters and leaves the cell
The cell membrane acts as a selectively permeable barrier, controlling which substances can enter and exit the cell. This regulation is crucial for maintaining the cell's internal environment, allowing necessary nutrients in while expelling waste products. Its primary role is to manage cellular transport and protect the cell's integrity.
Question 2: Which of the following is an example of a prokaryotic organism?
- Plant cell
- Animal cell
- Bacteria (Correct answer)
- Fungi
Correct answer: Bacteria
Prokaryotic organisms are characterized by their simple cellular structure, lacking a membrane-bound nucleus and other membrane-bound organelles. Bacteria are classic examples of prokaryotes, with their genetic material freely located in the cytoplasm. In contrast, plant cells, animal cells, and fungi are all eukaryotic, possessing a more complex internal organization.
Question 3: What process do plants use to convert sunlight into chemical energy?
- Cellular respiration
- Photosynthesis (Correct answer)
- Fermentation
- Transpiration
Correct answer: Photosynthesis
Photosynthesis is the fundamental process by which plants, algae, and some bacteria convert light energy, typically from the sun, into chemical energy. This energy is stored in glucose molecules, using carbon dioxide and water as reactants. This process is essential for producing food for the plant and releasing oxygen into the atmosphere.
Question 4: What is the role of mitochondria in a cell?
- Protein synthesis
- Photosynthesis
- Energy production (ATP) (Correct answer)
- Cell division
Correct answer: Energy production (ATP)
Mitochondria are often called the 'powerhouses' of the cell because their primary function is to generate adenosine triphosphate (ATP), the main energy currency of the cell. Through cellular respiration, mitochondria break down glucose to release energy, which is then used to fuel various cellular activities. This makes them vital for the cell's metabolic processes.
Question 5: Which organelle is responsible for protein synthesis?
- Nucleus
- Ribosome (Correct answer)
- Mitochondria
- Lysosome
Correct answer: Ribosome
Ribosomes are essential cellular organelles responsible for protein synthesis, also known as translation. They read the genetic instructions carried by messenger RNA (mRNA) and assemble amino acids into specific protein chains. This function is critical for all cellular activities, as proteins perform a vast array of structural and functional roles within the cell.
What is the primary function of the cell membrane?