Cell Biology Flashcards
What is the function of the nucleus?
Contains genetic material and controls cell activities.
Which cell structure is the site of protein synthesis?
Ribosomes.
Name three structures found in plant cells but not animal cells.
Cell wall; chloroplasts; permanent vacuole.
What type of organism is a prokaryotic cell?
Bacteria (or prokaryotes like bacteria).
How is a sperm cell adapted for its function?
Long tail to swim; many mitochondria for energy.
Define cell differentiation.
The process where a cell becomes specialised for its function.
What is the main difference between light and electron microscopes?
Electron microscopes have higher magnification and resolution.
How do you calculate magnification?
Magnification = image size / real size.
Where are chromosomes found in a cell?
In the nucleus.
What is the purpose of mitosis?
The purpose of mitosis is to:
- Grow – produce new cells for an organism to increase in size.
- Repair – replace damaged or dead cells (e.g., healing a cut).
- Asexual reproduction – produce offspring genetically identical to the parent (in some organisms like bacteria or plants).
Mitosis produces 2 identical daughter cells, each with the same number of chromosomes as the original cell.
What are stem cells?
Undifferentiated cells that can become various cell types.
Give one advantage of embryonic stem cells over adult stem cells.
Embryonic can differentiate into any cell type; adult are limited.
Define diffusion.
Net movement of particles from high to low concentration.
Name three factors that affect the rate of diffusion.
Concentration gradient; temperature; surface area.
What is osmosis?
Diffusion of water across a partially permeable membrane.
How does active transport differ from diffusion?
Requires energy; moves against concentration gradient.
How is a root hair cell adapted for absorption?
Long, thin extension increases surface area for absorption
Thin cell wall allows easier movement of water by osmosis
Large vacuole with low water potential helps draw in water
No chloroplasts as it’s underground and doesn’t photosynthesise
Many mitochondria to provide energy for active transport of minerals
What is the function of phloem and xylem?
Phloem transports sugars; xylem transports water and minerals.
Why is a high surface area to volume ratio important for cells?
Allows efficient exchange of materials (e.g.
What is the function of mitochondria?
Site of aerobic respiration; releases energy.
What does the cell membrane do?
Controls movement of substances in/out of cell.
What is the role of the vacuole in plant cells?
Contains cell sap; maintains turgor pressure.
Name three features of a bacterial cell.
Cell wall; plasmid DNA; flagella (some).
How is a nerve cell adapted for signalling?
Long axon; branched connections (synapses).
Myelin sheath.
