Cell Biology Flashcards
What are the main things in a animal cell/what are they functions?
Nucleus-which control the activities of the cell and contains the genetic material
cell membrane-control the passage of substance in and out the cell
What does plant cell have that an animal cell doesn’t have?
Plant cells have everything an animal call has
cell wall-made of cellulose and strengthens the wall
Permanent vacuole-filled with cell sap which supports the plant
Chloroplast-absorbs light to make food by photosynthesis
Describe the genetic material in a prokaryotic cell?
Bacterial cell
small in size
genetic material is NOT enclosed in a nucleus
Genetic material is a single DNA loop and there maybe one or small ring of DNA called plasmids
don’t contain mitochondria or chloroplast
What is a eukaryotic cell?
plant,animal and fungal cell
Eukaryotic have their genetic material enclosed in a nuclease
What roles does the bacteria cell take over?
Come in different shapes
In a bacterial cell the roles of mitochondria and chloroplast are taken over by the cytoplasm
What is the standard form for mm & cm?
UNITS STANDARD FORM
centimetres (cm)–100– 1 x 10 2
milimetres(mm)–1000– 1 x 10 3
What is magnification and what is the equation?
magnification is how many times larger the image is than the real object
MAGNIFICATION=SIZE OF IMAGE/SIZE OF REAL OBJECT
Explain diffusion and give an example?
diffusion is the spreading out of particles resulting in a net movement from an area of high conc to a low conc
EG. urea diffuses from the cell into the blood plasma for excretion by the kidney
What is osmosis?
diffusion of water from a dilute(mainly water) solution to a concentrated solution through a partially permeable membrane (some molecules to pass trough)
moves down conc gradient
What is active transport?
active transport moves substances against a concentration gradient from and area of low concentration to a high concentration and this requires respiration
Use a light microscope to observe and label animal and plant cells
METHOD
1) Place a tissue sample on the slide
2) add a few drops of suitable stain
3) lower a coverslip onto the tissue
4) place the slide on the microscope stage and focus on the cells using a low power
5) Change to high power and refocus
6) Draw the cell that can be seen
7) Add a scale line to the diagram
How do you calculate % mass?/how do you plot the change?
4) Calculate percentage mass change= change in mass of potato/initial mass of potato x 100
4) Plot the % change in mass against conc of sugar if the mass has gained plot above 0 % if it lost mass but it below the 0%
Why are plasmids in a bacterial cell?
- Plasmid are circles of DNA
- can be transferred from one cell to another
- allow genes to move from one cell to another
What is chromosomal DNA/what does the flagella do in the bacterial cell?
- Chromosomal DNA is the DNA of bacteria which is not found within a nucleus and is usually found as one circular chromosome
- Flagella is a tail like structure that rotates to help some bacteria to move
What are the factors that affect diffusion?
- difference in concentration- greater the conc gradient faster the rate of diffusion
- higher temp faster rate of diffusion
- large surface area, greater rate of diffusion
Describe the water movement in an plant and animal cell?
when water moves in an animal cell the cell will expand and burst
BUT in plant cell it will be swollen (turgid) and not burst because it has a cell wall
when water is going out the animal cell it shrinks because it is in a very concentrated solution
but water is going out the plant cell because it is in a concentrated solution
What does active transport allow?
Active transport allows sugar molecules to be absorbed from low conc in the gut into the blood which has a high conc
in plants it allows mineral ions to be absorbed into the plant root hairs from a very dilute solution in the soil.
In the potato practical how do you get the cylinder shape?
1) Use a cork borer to get a cylinder potatoes shape this ensure they are all the same diameter then use a scalpel to trim the cylinders at the same length
What do you do after you cut the potatoes?
2)measure the mass with the balance and the length with the ruler
Place cylinder in different concentration of sugar solution and label them you also put one cylinder in distilled water
What are the variable for the potato practical?
IV-conc of sugar solution
CV-the temp, the length of potatoes
DV-change in mass of the potatoes
What common mistake happens when you squeeze to much moisture out?
3)after 30 mins remove cylinder on a paper towel (removes moisture) and measure their mass and length again
squeezing too much moisture out will affect the amount of water lost and make your results invalid
Where does chemical reactions&aerobic respiration take place in an animal cell?
cytoplasm-chemical reaction takes place mitochondria-where aerobic respiration takes place
What is a ribosome/what cell contains ribosomes?
ribosomes-where proteins are made
animal cell
What is the standard form for um &nm?
UNITS STANDARD FORM
micrometres(um)–1000,000–1 x 10 6
nanometres(nm)– 1000,000,000– 1 x10 9
