cell biology

Question 1

What is a eukaryotic cell

Answer 1

a cell with a nucleus and membrane bound organelle

Question 2

What is a prokaryotic cell

Answer 2

A cell without a nucleus which is smaller than a eukaryotic cell

Question 3

Feature of a eukaryotic cell

Answer 3

Cytoplasm (Chemical reactions take place)
Ribosome (protein synthesis to turn DNA into protein on ribosome to make proteins and enzymes)
Mitochondria (site of respiration)
Nucleus (control centre)
cell membrane (controls what goes in and out of the cell)
Plant:
Cell wall ( gives structure)
Chloroplasts (photosynthesis)
Vacuole (keeps shape and storage of sap)

Question 4

Features of a prokaryotic cell

Answer 4

Plasmids
Ribosome
cell membrane
cytoplasm

Question 5

Where is DNA stored is different typed of cell

Answer 5

Eukaryotic cell
-Nucleus
Prokaryotic cells:
-Plasmids
-Nucleoid (single loop of DNA)

Question 6

convertions

Answer 6

1000nm= 1μm
1000μm= 1mm
10mm= cm
1000mm= 1m
1000m= 1km

Question 7

Pluripotent stem cells

Answer 7

can give rise to cells from all three different embryonic germ layers but once it goes down one path it can’t revert

Question 8

three embryonic germ layers

Answer 8

Ectoderm- give rise to Neurons and sensory cells
Mesoderm- give rise to the cardiovascular system and blood cells
Endoderm- Liver, lungs, bladders and germ cells(egg and sperm)

Question 9

Undifferentiated

Answer 9

not yet specialized

Question 10

magnification vs resolution

Answer 10

magnification= how big it is
Resolution= how clear it is

Question 11

Mitosis

Answer 11

-An X shaped chromosome is ready to divide
-A cell becomes larger and doubles the number of organelle
-During this time DNA is checked
-All of the chromosomes line up in the middle of the nucleus
-The nucleus disappears and spindles go from each chromosomes to opposite ends of the cell pulling the chromosomes apart
-when all of the chromosomes have been split the nucleus closes and two daughter cells have been formed

Question 12

Embryonic stem cells

Answer 12

stem cells that are totipotent and can differentiate into anything

Question 13

What is a stem cell

Answer 13

a cell that can be grown into more cells

Question 14

what is diffusion

Answer 14

the movement of particals from an area of high to low density

Question 15

factors affecting diffusion

Answer 15

concentration gradient
Blood supply
large surface area
small diffusion distance
moist surface

Question 16

Osmosis

Answer 16

The movement of particals to and area of lower concentration through a partially permeable membrane

Question 17

Surface area to body ratio

Answer 17

outside surface area : volume (volume should be 1)

Question 18

binary fission

Answer 18

the asexual reproduction of bacteria:
the cell will grow and replicate genetic material
the DNA strands move to opposite ends of the cell
Plasmids arranged randomly so one offspring cell may get more
new cell wall starts growing in the middle
once the cell wall has grown the two cells pull apart

Question 19

Bone marrow stem cells

Answer 19

can only turn into blood cells (red, white and platelets)

Question 20

conditions that can be treated by bone marrow stem cells

Answer 20

severe aplastic anaemia (bone marrow failure)
leukaemia – a type of cancer affecting white blood cells
lymphoma – another type of cancer affecting white blood cells
multiple myeloma – cancer affecting cells called plasma cells
certain blood, immune system and metabolic disorders – including sickle cell anaemia, thalassaemia, severe combined immunodeficiency (SCID) and Hurler syndrome

Question 21

Organisational hierachy

Answer 21

many cells make a tissue, many tissues make a organ many organs make an organ system and many organ systems make a organism

Question 22

required practical 1 equipment

Answer 22

light microscope
slide
microscope
onion
tweezers
iodine
white tile
pre made animal cell slides

Question 23

required practical 1 method

Answer 23

• peal off the top layer of the onion and place on the slide
• add a couple drops of iodine to stain the cells (goggles to prevent iodine to the eyes)
• gently place cover slip over the cells and avoid forming air bubbles - remove any excess stain
• place the slide on the stage of the microscope
• whilst looking through the ocular lense adjust the microscope going from the lowest to the highest resolution until the cells come into focus (be wary of the lenses though as to not allow the slide to come into contact with them
• draw what can be see and annotate diagram - remember to note down the magnification
• repeat steps 4-6 with the already prepared slides