B1: Cell Biology Flashcards
What are the differences between a prokaryotic cell and a eukaryotic cell?
A prokaryotic cell has no nucleus, e.g. A bacterial cell
Name the parts of a plant cell.
Cell wall Cytoplasm Permanent vacuole Chloroplasts Nucleus
What do plant cells have that animal cells do not?
A permanent vacuole, chloroplasts and a cell wall
Explain the process of mitosis.
- Everything in the cell duplicates
- The chromosomes line up in the centre of the cell
- The nucleus disappears
- The cell splits into two
- A membrane forms around the two cells
- A nucleus forms within each cell
Explain how diffusion works.
Diffusion is the movement of molecules from an area of high concentration to an area of low concentration.
Dissolved substances are also able to move in and out of cell membranes through diffusion.
Osmosis is often described as diffusion in water, explain how it works.
Osmosis is the movement of water through a semi-permeable membrane from an area of high water concentration to an area of low water concentration.
What is the formula for magnification?
Magnification = image size divided by real size
Name the parts of an animal cell.
Nucleus Cytoplasm Mitochondria Cell membrane Ribosomes
What is meant the the term ‘cell differentiation’?
Differentiation is the process in which a cell becomes specialised for its job - each cell carries out a specific function.
Give some examples of specialised cells.
Sperm cells are specialised for reproduction.
Nerve cells are specialised for rapid signalling.
Muscle cells are specialised for contraction.
Root hair cells are specialised for absorbing water and minerals.
Phloem and xylem cells are specialised for transporting substances.
Explain what stem cells are and how they can be used.
Stem cells are undifferentiated cells, they are not specialised and so can do the job of any cell. Stem cells can be used to cure disease through a transplant, replacing any faulty cells causing the illness.
What are the different types of stem cells?
Stem cells can be found in early human embryos (embryonic), or in specific places within adults such as bone marrow. Within plans, stem cells can be found in the meristems.
Explain how active transport works, give an example.
Active transport is the transport of substances against a concentration gradient using energy. An example of active transport is when root hairs need to take in minerals and water.
Explain how gas exchange happens in the lungs.
The lungs contain millions of little air sacs called alveoli where gas exchange takes place. Oxygen is transferred to the blood and to remove waste carbon dioxide from it.
How are the villi adapted?
Large surface area
Good blood supply
Single layer of surface cells
