Cell-level systems

Question 1

What is the difference between an eukaryote and prokaryote and give examples of both

Answer 1

An eukaryotic cell has a nucleus eg plant or animal
A prokaryotic cell doesnt have a nucleaus eg bacteria

Question 2

What are the stages of light microscopy

Answer 2

Place stage at its lowest
Select lowest magnification objective lens
Place slide with sample on stage
Raise stage to highest
Slowly lower stage
Turn fine focus knob
If needed change magnification

Question 3

What are some common stains and what are they used for

Answer 3

Methylene blue, animal cell nuclei
Iodine , plant cell nuclei
Crystal violet, bacteria cell walls

Question 4

Compare the images, resolutions and other factors of light and electron microscopes

Answer 4

Electron, black and white, Expensive, non portable, up to 1nm
Light, coloured, Cheaper, portable up to 0.2 mewmeteres

Question 5

Compare a TEM and SEM

Answer 5

TEM -most magnified images, beam of electrons through sample
SEM -3d surface image

Question 6

What is DNA made of

Answer 6

Nucleotides, joined together each made of a sugar phosphate and base

Question 7

Explain the process of transcription and translation

Answer 7

DNA unzips and used as template, mRNA made through complimentary base pairing, mRNA travels to ribosome. Each codon then codes for a protein which makes up amino acids.

Question 8

What are the factors affecting enzyme reactions

Answer 8

temperature, increase until denaturing
pH, increase until optimum pH
enzyme and substrate concentration

Question 9

What are carbs, lipids and proteins

Answer 9

carbs are polymers made from sugars such as starch
lipids are fats and oils
proteins are polymers made from amino acids

Question 10

what is the equation for fermentation

Answer 10

C6H12O6 -> 2CO2 + 2H5OH

Question 11

How do you test for starch

Answer 11

Boil the leaf for a minute in water then boil in ethanol to remove chlorophyll, wash soften and add iodine, which should turn navy

Question 12

How do you prove chlorophyll is needed for photosynthesis

Answer 12

Variegated leaves

Question 13

What are the factors affecting the rate if photosynthesis

Answer 13

Light intensity, temperature and CO2

Question 14

What factors affect diffusion rate

Answer 14

concentration gradient, distance and surface area

Question 15

How is DNA replicated

Answer 15

DNA unzips , complimentary base pairing, all chromosomes line up in the middle, move to opposite ends and cell splits