Cell biology

Created by

Emily Churchill

Cards (40)

What is the basic unit of life?
Cells
What can we see with a normal light microscope?
Cells and possibly the nucleus
What does an electron microscope allow us to see?
Finer details of organelles
What is the resolving power of electron microscopes compared to light microscopes?
Higher resolving power and resolution
How can we calculate the actual size of a cell?
Image size divided by magnification
What are the two main groups of cells?
Eukaryotic and prokaryotic cells
What do eukaryotic cells contain?
A nucleus with DNA
What do prokaryotic cells lack?
A nucleus
What is the function of the cell membrane?
Keeps everything inside the cell
What does semi-permeable mean in relation to the cell membrane?
Allows certain substances to pass through
What do plant cells and most bacteria have that provides structure?
A cell wall made of cellulose
What is cytoplasm?
The liquid that makes up the cell
Where does respiration take place in a cell?
In the mitochondria
What is the role of ribosomes?
Assemble or synthesize proteins
What do chloroplasts contain and where does photosynthesis occur?
Contain chlorophyll and perform photosynthesis
What is stored in the permanent vacuole of plant cells?
Sap
How do bacteria multiply?
By binary fission
If we start with one bacterium, how many will there be after one hour?
64 bacteria
What is the theoretical number of bacteria after 6 hours?
$6.87 \times 10^{10}$
What is the procedure for culturing bacteria on agar?
Use aseptic technique to avoid contamination
Lift the lid of the dish towards a flame
Use sterilized equipment to place bacteria
Incubate at 25°C
How do we calculate the area of a circle in a bacterial culture?
$\frac{\pi d^2}{4}$
What do eukaryotic cell nuclei contain?
DNA stored in chromosomes
How many pairs of chromosomes do humans have?
23 pairs
What are gametes and how many chromosomes do they have?
They have 23 chromosomes, not pairs
What process do new cells undergo for growth and repair?
Mitosis
What are the steps of mitosis?
Genetic material is duplicated
Ribosomes and mitochondria double
Nucleus breaks down
Chromosomes pulled to opposite sides
New nuclei form
Two identical cells are produced
What is the role of stem cells?
They can specialize into different cell types
Where are stem cells found in humans?
In bone marrow and embryos
How can stem cells be used in medicine?
To combat conditions like diabetes and paralysis
What are the ethical considerations of cloning for stem cells?
Weighing the benefits against moral implications
What is diffusion?
Movement from high to low concentration
What is passive transport?
Movement that does not require energy
What is osmosis?
Diffusion of water across a membrane
What happens to a cell in a high glucose concentration outside?
Water moves out, decreasing mass
How can the rate of diffusion be increased?
By increasing concentration difference, temperature, or surface area
What is the procedure for an osmosis practical using potatoes?
Cut equal size cylinders from potatoes
Weigh and place in sugar solutions
After a day, weigh again
Calculate percentage change in mass
Plot against sugar concentration
What does the x-axis crossing point in the osmosis graph indicate?
No change in mass, no osmosis
What is active transport?
Movement against a concentration gradient using energy
How do carrier proteins function in active transport?
They use energy to move substances
What is an example of active transport in plants?
Moving mineral ions into root hair cells