Cell Structure

Question 1

Define Mgnification

Answer 1

How much bigger an image seems compared to the origional object

Question 2

Define Resolution

Answer 2

The clearness of an image produced by a microscope

Often said as the ability to distinguis between to points of a certain distance apart

Question 3

What are 4 advantages of a light Microscope

Answer 3

Cheap
Easy to use
Portable (Field work)
Able to study whole organisms

Question 4

How do Laser Scanning Microscopes form an image

Answer 4

Scan an object point by point and then transfer that onto a computer

Question 5

What is the main difference between a TEM and SEM

Answer 5

Transmission electron microscopes fire electrons THROUGH the specimin, whereas SEM bounce electrons off the surface.

Question 6

Why do you stain a specimin

Answer 6

In order to create contrast and see the specimin easier

Question 7

What is known as the all purpose stain?

Answer 7

Methylene Blue

Question 8

What stains DNA and chromosomes dark red

Answer 8

Acetic Orsin

Question 9

What stains Cytoplasm

Answer 9

Eosin

Question 10

What stains lipids

Answer 10

Sudan Red

Question 11

What stains starch black

Answer 11

Potassium Iodide (Iodine)

Question 12

What stains cellulose yellow?

Answer 12

Potassium Iodide (Iodine)

Question 13

How do you use a stage micrometer to calibrate an eyepiece graticule

Answer 13

Place a stage micrometer on the stage and then compare it at your magnification to the eyepiece graticule

Then use I = A x M to work out the size of divisions

Question 14

What feature of the nuclear envelope allows mRNA to move out

Answer 14

The nuclear pores

Question 15

What is made in the Nucleolus

Answer 15

Ribosomes

Question 16

What is the Structure and Function of RER

Answer 16

A system of membranes and fluid-filled cavities (cisternae), coated with ribosomes

RER is the transport system of the cell

When the ribosomes on the surface make proteins they instantly move into the RER where they are transported to the Golgi apparatus

Question 17

What is the Stricture and function of the SER

Answer 17

System of membranes and Cisternae

Contains enzymes involved in synthesis of Cholesterol, lipids and hormones

Also used to transport and absorb lipids

Question 18

What is the function of the Golgi apparatus

Answer 18

Modification and preparation of materials

E.g proteins can be modified by adding sugar or lipids to make glycoproteins and lipoproteins

Question 19

Describe the structure of a ribosome

Answer 19

Made in the nucleolus as 2 separate subunits (40s and 60s)

Combine outside the nucleus to form a ribosome

Question 20

What are the stages of protein synthesis

Answer 20

mRNA instructions made in nucleus

mRNA leaves nucleus through nuclear pore

Binds to a ribosome

Protein is then made in the RER by the ribosome

Pinched off as a vesicle by the RER

Vesicle fuses with Golgi apparatus

Protein is packaged and ready for release

Pinched off as a vesicle

Vesicle fuses with plasma membrane

Membrane opens to release protein outside the cell