Topic 1 - Cell Biology Flashcards
(28 cards)
Name 5 subcellular structures that both plant and animal cells have
- Nucleus
- Cytoplasm
- Cell Membrane
- Mitochondria
- Ribosomes
What 3 things do plant cells have that animal cells don’t?
- Cell wall
- Permanent vacuole
- Chloroplasts
Where is genetic material found in:
a). Animal cells
b). Bacterial cells
a). Nucleus
b). Loose in the cytoplasm, plasmids
What type of organisms are bacteria?
Prokaryotes
What type of organisms are plant cells?
Eukaryotes
Which gives a higher resolution - Light or Electron microscope?
Electron
Give the formula for magnification
Magnification = image size ÷ real object size
What is cell differentiation?
A process in which a cell changes to become specialised for a job
Give 3 ways that a sperm cell is adapted for swimming to an egg cell
- a long tail allows it to propel itself
- streamlined head to help propel itself
- lots of mitochondria to produce the energy needed
What are chromosomes?
Coiled up lengths of DNA molecules
What is the cell cycle?
A series of stages in which multicellular organisms divide to provide new cells
What is mitosis used for by multicellular organisms?
Used to grow or repair cells that have been damaged
What is the name of the process by which bacteria divide?
Simple cell division (binary fission)
a). What is the maximum temperature that microorganisms should be grown at in a school lab?
b). Why shouldn’t a temperature above this be used?
a). 25°C
b). Harmful pathogens are more likely to grow
A bacterial cell has a mean division time of 30 minutes. How many cells will it have produced after 2.5 hours? Show your working.
- 2.5 hours x 60 = 150 minutes
- 150 minutes ÷ 30 minutes = 5 divisions
- 2^5 = 2 x 2 x 2 x 2 x 2 = 32 cells
Give 3 ways in which you can make sure an experiment testing the effects of antibiotics on bacteria has not been contaminated
- Petri dishes and culture medium must be sterilised before use, to kill any unwanted bacteria
- Sterilise an inoculating loop by passing it through a hot flame before use
- After transferring the bacteria, the Petri dish should be lightly taped on, to prevent more microorganisms from entering
Give 2 ways that embryonic stem cells could be used to cure diseases
- Replace faulty faulty cells in sick people
- make insulin producing cells to people with diabetes
- nerve cells for people paralyzed with spinal injuries
Why might some people be opposed to the use of human embryos in stem cell research?
Deemed unethical for some as each embryo is a potential human life
What is diffusion?
The spreading out of particles from an area of higher concentration to an area of lower concentration
Give 2 ways in which to speed up the diffusion rate
- bigger concentration gradient
- higher temperature (particles have more energy so move around faster)
Name 3 substances that can move through cell membranes, and 2 that can’t
- Glucose, amino acids and water (small molecules) can move in and out of the cell
- Starch and Proteins (big molecules) can’t fit through the membrane
What is osmosis?
The movement of water molecules across partially permeable membrane from high to low water concentration.
What is Active Transport?
The passage of particles from an area of low to high concentration.
Give 2 main differences between active transport and diffusion.
- Active transport requires energy from respiration to work
- Active absorbs particles instead of spreading them out like in diffusion
