Microscopy and cell structures.

Question 1

What is meant by magnification?

Answer 1

The extent to which the actual size if the object is enlarged into a image.

Question 2

What is meant by resolution?

Answer 2

The ability to distinguish between 2 points.

Question 3

What is the equation triangle for microscopy.

Answer 3

Image size

Magnification Actual size

Question 4

How do you calibrate a microscope?

Answer 4

Place a stage micrometer on the stage of the microscope.
Line up one of the divisions on the eyepiece graticule with a fixed point on the stage micrometer.
Count the number of divisions on the eyepiece graticule that correspond with a set measurement on the stage micrometer.
Calculate the distance in micrometres of one division on the eyepiece graticule

Question 5

What is a TEM microscope?

Answer 5

Transmission electron microscope.

Question 6

How does a TEM microscope work?

Answer 6

Electron beams pass through the specimen .

Question 7

What is a SEM Microscope?

Answer 7

Scanning electron microscope.

Question 8

How does a SEM microscope work?

Answer 8

Electron beams are aimed at the specimen.

Electrons are reflected back from the specimen and detected.

Question 9

What is the function of the nucleus?

Answer 9

Contains genetic information.

Question 10

Give some key feature of the nucleus.

Answer 10

Surrounded by nuclear envelope.
Contains chromatin.
Contains a nucleolus.

Question 11

What is the function of the mitochondria?

Answer 11

ATP production through aerobic respiration.

Question 12

Give some key features of the mitochondria.

Answer 12

Double membrane - inner membrane folds to form cristae .

Internal fluid is called the matrix.

Question 13

What is the function of the lysosome?

Answer 13

Breaking down waste. (Old organelles ).

Question 14

Give some key features of lysosomes.

Answer 14

Specialised vesicles containing hydrolytic enzymes .

Question 15

What is the function of the smooth endoplasmic reticulum?

Answer 15

Lipid and carbohydrate synthesis.

Question 16

Give some key features of the smooth ER?

Answer 16

Contain flattened membrane-bound sacs called cisternae.

Question 17

What is the function of the rough endoplasmic reticulum?

Answer 17

This is where protein synthesis happens.

Question 18

Give some key features of the rough ER.

Answer 18

Cisternae bound to ribosomes.

Have ribosomes on the surface.

Question 19

What is the function of the golgi apparatus?

Answer 19

Modifies proteins and packages them into vesicles.

Question 20

Give some key features of the golgi apparatus.

Answer 20

Contains ribosomes.

Has flattened sacs.

Question 21

What is the function of The cytoskeleton?

Answer 21

Maintains cell shape.
Control of cell movement and of organelle movement in cells.
Compartmentalisation of organelles.

Question 22

Give some key features of the cytoskeleton.

Answer 22

It is made up of microfilaments to control cell movement and cytokinesis.
It is also made up of microtubules to regulate shape and organelle movements. They form centrioles and spindle fibres. .

Question 23

What is the function of the flagella and cilia?

Answer 23

Flagella Enables cell movement.

Cilia move substances across cell surface.

Question 24

Explain the differences between eukaryotic and prokaryotic cells,

Answer 24

Prokaryotic cells have a singe strand of DNA not enclosed in a nucleus like a eukaryotic cell.
Prokaryotic cells have smaller ribosomes (70S) eukaryotic have larger (80S).
Some prokaryotic cells have flagella.
Prokaryotic cell walls is made up of peptidoglycan and the cell walls of a eukaryotic cell is made up of chitin.