Cell Biology

Question 1

What happens in binary fission ?

Answer 1

• plasmid replicated
• cell gets bigger and plasmids move to opposite poles
• cytoplasm divides and new cell wall forms
• each new cell has a copy of the plasmid

Question 2

What is cell differentiation

Answer 2

The process by which a cell changes to become SPECIALISED to for a certain job

Question 3

What changes happen within a cell during differentiation

Answer 3

Different subcellular structures form and it becomes a new cell suited for specific functions

Question 4

When is cell development peaked in animal and plant cells

Answer 4

Early development in animal cells and never stops in plants

Question 5

What are undifferentiated cells called

Answer 5

Stem cells

Question 6

What are the 5 examples of specialised cells

Answer 6

Sperm, Nerve, Muscle cells, Root hair, phloem and xylem

Question 7

How are phloem and xylem specialised for their job

Answer 7

Long cells with hollow centres to allow easier transport

Question 8

What are chromosomes

Answer 8

Coiled up lengths of dna molecules

Question 9

What do chromosomes do

Answer 9

Carry large numbers of genes which control different characteristics

Question 10

What is mitosis

Answer 10

The cloning of cells to replace or repair damaged cells and allow for growth

Question 11

What are prokaryotes

Answer 11

Cells where the DNA is not stored in a nucleus

Question 12

What are the organelles within prokaryotic cells

Answer 12

No mitochondria, single strand of DNA that floats freely, plasmids (small rings of dna) cell wall and membrane

Question 13

What is an example of a prokaryotic cell

Answer 13

Bacteria’s

Question 14

What are eukaryotic cells

Answer 14

Cells where the dna is stored within the nucleus

Question 15

What are examples of eukaryotic cells

Answer 15

Animal and plant cells

Question 16

What do eukaryotic cells contain (both plant and animal) ?

Answer 16

-Nucleus
-cytoplasm
-cell membrane
-mitochondria
-ribosomes

Question 17

What do just plant cells contain

Answer 17

• cellulose Cell wall
  -Permanent vacuole
  -chloroplasts

Question 18

Why do we use microscopes

Answer 18

Easier to see organelles

Question 19

What are the advantages of light microscopes

Answer 19

Cheap

Question 20

What are the advantages of electron microscopes

Answer 20

Larger magnification
Better resolution
Than light microscopes

Question 21

How do you work out magnification

Answer 21

Image size \ real size

Question 22

What is the microscope RP

Answer 22

1. Add a drop of water to a clear slide
2. Cut onion into separate layers and then peel off epidermis tissue
3. Using tweezers place tissue onto the water on the slide
4. Add a drop of iodine to stain sample
5. Place cover slip over top to seal

Question 23

What is the Culturing microorganisms RP

Answer 23

Bacteria cultured in either nutrient broth or agar jelly
Growth on agar forms visible colonies

Question 24

Why is the bacteria cultured at 25 degrees

Answer 24

To not create human pathogens

Question 25

What is the microorganism Rp used to
Investigate and the method

Answer 25

The effect of antibiotics

1. Place paper disks soaked in antibiotic solutions onto agar plate with cultures on
2. Culture for 48 hours at 25 degrees
3. Measure clear zone surrounding (inhibition zone)

The most effective will have the largest inhibition zone

Question 26

How do you keep the microorganism RP sterile

Answer 26

By using high heat on instruments to kill any undesirable contaminants

Petri dish only opened next to flame

Stored upside down to avoid condensation dripping onto the samples with lid lightly taped on