Cell Biology Flashcards
Give two examples of eukaryotic cells.
Plant and Animal cells
Give one example of a prokaryotic cell.
Bacterial cells
Where is the genetic material located in a bacterial cell?
In the plasmids
What are the 5 similarities between plant and animal cells?
A nucleus
Cytoplasm
Cell membrane
Mitochondria
Ribosomes
What sub cellular structures are only found in plant cells?
Chloroplasts
Cell wall
Permanent vacuole
When do animal cells differentiate?
Early stages
When do plant cells differentiate?
Throughout life
How are sperm cells specialised?
Tail (flagellum) to help navigate
Lots of mitochondria in midsection for energy to help swim
Acrosome (enzyme) at head to digest egg wall
How are nerve cells specialised?
Long axon to carry messages over long distances
Dendrites at the ends to connect to other nerve cells
How are muscle cells specialised?
Long so they have space to contract
Lots of mitochondria to generate energy for contraction
How are root hair cells specialised?
Big surface area for absorbing water and mineral ions from soil
What is the formula for magnification?
Size of image/size of real object
What does the nucleus contain?
Chromosomes made of DNA molecules
What are chromosomes normally found in?
Pairs
What are chromosomes made of?
Molecules of DNA.
What do genes do?
Encode/produce proteins
What is the cell cycle?
Involved in cell growth and division. Involves mitosis which allows for growth, repair and asexual reproduction of cells.
What is the first stage of the cell cycle?
Growth stage - extra sub-cellular structures are produced. Cell chromosomes are replicated so that there are two sets.
What is the 2nd stage of the cell cycle?
Mitosis - Chromosomes are pulled to opposite ends of the cell. The nucleus splits in two. Mitosis ensures both daughter cells have same chromosomes.
What is the 3rd (last) stage of the cell cycle?
Two identical cells are created by division of cytoplasm and cell membrane.
Where are stem cells found in humans?
Bone marrow and embryos
What is the difference between stem cells found in bone marrow and embryos?
Stem cells in embryos can differentiate into most cell types, ones in bone marrow can only differentiate into a few.
Where are stem cells found in plants?
Meristem
What the advantages of stem cell research?
Stem cells may replace damaged cells in the body
Plant stem cells can produce cloned plants cheaply and quickly
Therapeutic cloning - creates an embryo with the same genome as patient - their body will not reject the stem cells from embryo
What are the disadvantages of stem cell research?
Viral infections
Ethical/religious beliefs - may believe that life begins at conception
What 3 factors affect the rate of diffusion?
Membrane surface area (larger surface area = faster rate of diffusion)
Temperature (higher temperature = faster rate)
Concentration gradient (bigger difference in concentration = faster rate)
What is osmosis?
Movement of water across a semi-permeable membrane from a dilute to concentrated solution.
What is active transport?
Movement of particles against a concentration gradient. This requires energy.
What are the 3 main forms of transport in cells?
Osmosis
Diffusion
Active Transport
What sub-cellular structures missing from prokaryotic cells that are in eukaryotic cells?
Nucleus
Mitochondria
Chloroplast
