Chapter 1- Cells , Microscopy

Question 1

what is the function of Centrioles

Answer 1

• centrioles are involved in the movement of chromosomes in the cell division

Question 2

what is the function of microtubules
*hint 2

Answer 2

They support the cells shape and help it move.
They help organise and move organelles in the cell.

Question 3

8Os Ribosomes are found where in a cell

Answer 3

cytoplasm
ER

Question 4

70s Ribosomes are found where

Answer 4

Chloroplasts
Mitochondria

Question 5

what is the function of Ribosomes

Answer 5

They provide site for Protein synthesis

Question 6

Function of ER

Answer 6

-They help transporting of protein
-synthesis of polypeptides
-creates transport vesicles

Question 7

Function of smooth ER

Answer 7

Involved in synthesis of hormones and lipids

Question 8

Function of Golgi body

Answer 8

They modify the proteins for functionality

Question 9

Steps taken through the Golgi for modification of proteins
*hint 5 steps

Answer 9

1- Vesicles are released containing protein from the rough ER
2-These vesicles attach onto the Golgi body and proteins here are modified
3-After modification the vesicles now carry the new modified protein off from the Golgi
4-Some escape to the cell membrane where they are taken out of the cell (exostosis)
5-Some vesicles are Lysosome containing Hydrolase enzyme

Question 10

Function of Granum in the chloroplasts

Answer 10

They contain the chlorophyll molecules that help with absorption of light energy then transfer it to other molecules to generate ATP.

Question 11

state the Mitochondrion’s funtion

Answer 11

they act as the site of aerobic respiration whereby glucose is broken down which results into release of energy to create ATP

Question 12

what is the function of Cristae in the mitochondria

Answer 12

they increase the surface area for enzymes

Question 13

Function of Lysosomes

Answer 13

They breakdown of unnecessary/ old organelles

Question 14

which cells use Lysosomes

Answer 14

White blood cells, phagocytes to digest engulfed pathogens

Question 15

what substances are present in the cell wall

Answer 15

Primary layer- Cellulose
Secondary layer-Lignin
Middle lamella- Pectin

Question 16

What is the envelope of a virus made up from.

Answer 16

Phospholipids

Question 17

Mention 3 differences between Prokaryotes and eukaryotes

Answer 17

-PRO only has 70s ribosomes present while EUK has 80s
-PRO has no membrane bound organelles EUK does
- PRO do not have centrioles EUK does
- PRO are smaller (1-10um) while EUK is larger (5-100um)
-PRO do not have a nucleus while EUK have a nucleus

Question 18

Centrioles are present in Plant cells, True or False?

Answer 18

FALSE

Question 19

1 centimeter to micrometers

Answer 19

1cm= 10000

Question 20

1 mm to nanometer

Answer 20

1mm = 1,000,000 nanometers

Question 21

equation of magnification

Answer 21

Image divided by Actual size
I / A M

Question 22

How does a light microscope view the specimen

Answer 22

Through illumination of light

Question 23

The Max. magnification of light microscopes are

Answer 23

x1500

Question 24

what is magnification

Answer 24

The number of times larger an image is compared to its actual size.

Question 25

what type of stains are seen in light and electron microscopes

Answer 25

light- coloured dyes electron-heavy metals

Question 26

what is resolution

Answer 26

the ability to distinguish between 2 objects that are close together

Question 27

max resolution in light and electron

Answer 27

light-200nm cannot see ribosomes electron-0.5nm

Question 28

suggest 3 organelles that are bounded by a single membrane

Answer 28

-lysosome -vacuole -ER -Golgi body

Question 29

Suggest 3 organelles that are bound by no membrane

Answer 29

-ribosomes -centrioles -microvilli -flagella -cillia -cytoskeleton

Question 30

suggest 3 organelles that are bounded by double membrane

Answer 30

-mitochondria -nucleus -chloroplast

Question 31

what does the structure of viruses contain

Answer 31

-RNA/DNA that is self replicating -protein coat/capsid -some have a slime capsule

Question 32

2 categories of electron microscopes

Answer 32

1) transmission electron microscopes- electrons are PASSED through the specimen 2)Scanning electron microscopes- This DETECTS electrons that have been reflected from the surface of the specimen.

Question 33

why is the TEM good?

Answer 33

This is because it can allow thin surfaces to be observed and thus can see inside cells

Question 33

why is the SEM good?

Answer 33

The surface structures can be seen A 3-D image can be gotten which can interpret the structures better

Question 34

differences between the SEM and TEM

Answer 34

- The SEM cannot achieve the same resolution like the TEM (higher) - 3D surface sample for SEM while 2D internal structure - SEM have a lower magnification than TEM - SEM can use larger and thicker samples while TEM is limited to thin and transparent ones

Question 35

why can only dead molecules be used for an electron microscope

Answer 35

this is due to water boiling at room temperatures when in a vacuum so all specimens must be dehydrated.

Question 36

evaluate the use of a light microscope

Answer 36

+ Can view living cells + coloured image + does not require heavy staining -Specimens must be thin enough -Low resolution (200nm)

Question 37

Evaluate the use of an electron microscope

Answer 37

+ Short wavelength so has a very high resolution (0.2-10nm) + high magnification -Cannot see living organisms -black and white images -prepping is difficult

Question 38

Organelles that can be seen by an electron microscope

Answer 38

- Endoplasmic reticulum - Ribosomes - Vacuoles