Cell Biology Flashcards
(30 cards)
What is a cell membrane and what is its function?
A thin barrier that surrounds the cell, controlling what enters and leaves the cell through selective permeability.
Name the three main parts of a typical animal cell.
Cell membrane, cytoplasm, and nucleus.
What is the function of the nucleus in a cell?
Controls the cell’s activities and contains the genetic material (DNA).
What is cytoplasm?
A jelly-like substance inside the cell where chemical reactions take place.
How do plant cells differ from animal cells?
Plant cells have a cell wall, chloroplasts, and a permanent vacuole that animal cells don’t have.
What is the function of chloroplasts?
They contain chlorophyll and are the site of photosynthesis in plant cells.
What is the cell wall made of and what is its purpose?
Made of cellulose, it provides structural support and protection to plant cells.
What does the permanent vacuole contain and what is its function?
Contains cell sap (water and dissolved substances) and helps maintain the plant’s shape and structure.
What are mitochondria and what do they do?
Small structures in the cytoplasm where aerobic respiration occurs, releasing energy for the cell.
What are ribosomes responsible for?
Protein synthesis - they make proteins according to instructions from the DNA.
Why are root hair cells specialised?
They have long projections to increase surface area for absorbing water and minerals from soil.
How are nerve cells adapted for their function?
They have long axons to carry electrical impulses over long distances and branched dendrites to connect with other nerve cells.
What makes muscle cells specialised?
They contain protein fibres that can contract and relax to produce movement.
How are red blood cells adapted for carrying oxygen?
They have no nucleus (more space for haemoglobin), are biconcave in shape (larger surface area), and contain haemoglobin.
What is a tissue?
A group of similar cells working together to perform a specific function.
Give an example of a plant tissue and its function.
Xylem tissue - transports water and minerals from roots to leaves.
What is an organ?
A group of different tissues working together to perform a specific function.
What is an organ system?
A group of organs working together to perform a major function in the body.
What is the hierarchy of organisation in multicellular organisms?
Cell → Tissue → Organ → Organ System → Organism.
What type of microscope is needed to see cell organelles clearly?
Electron microscope.
What is the difference between prokaryotic and eukaryotic cells?
Prokaryotic cells have no nucleus (DNA freely in cytoplasm), eukaryotic cells have a nucleus containing DNA.
Give an example of a prokaryotic cell.
Bacterial cell.
How are sperm cells specialised for their function?
They have a tail for swimming, lots of mitochondria for energy, and an acrosome containing enzymes to penetrate the egg.
What is the function of phloem tissue in plants?
Transports sugars (products of photosynthesis) around the plant.
