Cell biology Flashcards
(22 cards)
What are the 2 types of cells?
Prokaryotic and Eurkaryotic
Eukaryotic cells contain the DNA in a ____, while prokaryotic cells ______.
nucleus, do not
Animal and Plant cells are both _______.
Eukaryotes
How does the size of prokaryotic and eukaryotic cells differ?
Prokaryotes are much smaller then eukaryotes.
What is the meaning of “centi”, “milli” “micro” and and “nano”?
Centi = 1/100th
Milli = 1/1,000th
Micro = 1/1,000,000th
Nano = 1,000,000,000th
Describe orders of magnitude.
1 order of magnitude = 10x bigger.
To count the orders of magnitude, count the zeros.
What is the structure of an animal cell?
Nucleus - contains DNA
Cytoplasm - watery solution where chemical reactions take place
Cell membrane - encloses the cell and control molecules entering / leaving
Mitochondria - where aerobic respiration takes place
Ribosomes - the site of protein synthesis
What is the structure of a plant cell?
The same as an animal cell, but contains extra things:
Chloroplasts - contain chlorophyll and are the sites of photosynthesis.
Cell wall - made of cellulose, strengthens the cell.
Vacuole - contains cell sap and gives the cell it’s shape.
How do prokaryotic cells store DNA?
In a loop of DNA.
Some prokaryotes may contain plasmids, which also store DNA.
Most animal cells are ____. They have _____, which _______
specialised, adaptations, help them carry out a specific function
What is the purpose of the sperm cell? What adaptations does it have?
To join with the egg cell.
Has a tail for swimming
Contains mitochondria for energy
Contain enzymes for digesting the cell wall
Nucleus only contains 23 chromosomes
What is the function of a nerve cell? What adaptations does it have?
To carry electrical impulses around the body.
Has synapses to send impulses to connected nerve cells
Axon carries electrical impulses
Myelin shields axon
Dendrites increase surface area so other nerve cells can connect
What is the function of muscles cells? What adaptations do they have?
Contract.
Have protein fibers that can shorten to contract the muscle
Full of mitochondria to provide energy required to contract.
What is it called when plant cells become specialized?
Differentiation
What are the specializations of root hair cells?
The root hair increases the surface area
Do not contain chloroplasts as they have no access to light (underground)
What are the specializations of xylem cells?
They form long tubes
No internal structure
Thick walls containing lignin
What are the specializations of phloem cells?
No nucleus
Limited cytoplasm
Cell walls have pores (sieve plates). These allow dissolved sugar to pass through
Have a companion cell with mitochondria for energy (connected via pores)
(Required practical) Describe the use of a light microscope and how to make a scale.
Place slide on stage (use clips on stage)
Select lowest magnification objective lens
Focus using coarse focusing wheel so the lens and slide are almost touching (look from side)
Look down eyepiece. Use coarse focusing wheel to focus cells
Use fine focusing wheel to clearly focus cells
Change objective lens
Focus on cells again
Make pencil drawing of the cell
Place clear ruler on slide. Measure FOV in mm
Make a scale on the pencil drawing.
Light microscopes have limited _______.
magnification and resolution
How do bacteria multiply? How often?
Simple cell division
1 splits into 2 (binary fission)
Once every 20m, assuming optimal conditions
How to carry out the culturing organisms practical?
Clean bench with disinfectant solution
Sterilise inoculating loop using Bunsen burner flame.
Open sterile agar plate near bunsen burner flame
Spread bacteria over plate using inoculating loop
Place sterile filter paper discs containing antibiotic on the plate.
Incubate at 25c
