Cell structure

Question 1

Protoplasm

Answer 1

all the living parts of a cell

Question 2

Ultrastructure

Answer 2

is the detail of a structure as seen using an electron microscope

Question 3

Objective lens

Answer 3

Low power
Medium power
High power

Question 4

Light microscope parts

Answer 4

Objective lens
Clips
Light
Eye piece lens
Stage
Coarse focus
Fine focus

Question 5

Experiment using a light microscope : To examine a plant cell

Answer 5

Sample of onion cells
Stain with iodine - to see cell wall and nucleus
Apply coverslip at 45° angle to avoid air bubbles

Question 6

Organelles

Answer 6

Cells contain a variety of internal structures called organelles.
An organelle is a component that preforms specific functions for the cell (eg:) mitochondria-> respiration

Question 7

Light microscope magnifys..

Answer 7

1000 times

Question 8

Electron microscope magnifies

Answer 8

250,000 times

Question 9

SEM

Answer 9

Scanning electron microscope
(Surface)

Question 10

TEM

Answer 10

transmission electron microscope (Internal)

Question 11

Chlorophyll

Answer 11

Green pigment

Question 12

Function of the cell membrane

Answer 12

• Retain cell contents
• Controls what enters and leaves the cell (allows water and oxygen to pass freely however sodium ions and large proteins have to be moved across using energy)
• Gives some support
• Semi permeable

Question 13

What is the cell membrane made of?

Answer 13

1. Phospholipid bilayer (structural lipid)
2. Proteins

Question 14

Ultrastructure of the nucleus

Answer 14

The nucleus is the control centre of the cell (contains DNA, RNA)
The nucleus is surrounded by a double membrane with nucleur pores
Allows controlled entry and exit of molecules into and out of the nucleus

Question 15

DNA

Answer 15

Deixyribonucleic Acid

Question 16

Chromatin

Answer 16

Chromosomes intertwine to from chromatin when the cell is not divided

Question 17

Nucleolus

Answer 17

Location: nucleus
Function: makes ribosomes

Question 18

Function of ribosomes

Answer 18

Makes protein

Question 19

Mitochondria Function

Answer 19

• Supply energy to the cell (known as the powerhouse)
• Site of respiration in the cell (release of energy from food

Question 20

Cells with lots of mitochondria include:

Answer 20

Animals: muscle and liver
Plant: meristem (growing tips of roots and shoots)

Question 21

Inactive mitochondria includes

Answer 21

Outer membrane
Inner membrane
Infolding (Christae) (not a lot)
Loop of DNA

Question 22

Active mitochondria includes

Answer 22

Outer membrane
Inner membrane
Infolding (christae) ( a lot)
Loop of DNA

Question 23

Function of Christae

Answer 23

Increases the surface are for respiration therefore more energy is released.

Question 24

Chloroplast: Function

Answer 24

Photosynthesis

Contains chlorophyll (green pigment)
Magnesium - needed for chlorophyll

Question 25

Cell wall function

Answer 25

Cell walls - cellulose - support and strength They’re fully permeable

Question 26

Prokaryotic cell

Answer 26

- Don’t have a nucleus or membrane enclosed organelles - Are small/ microscopic (Eg:) bacteria 🦠

Question 27

Eukaryotic cell

Answer 27

- Do have a nucleus and membrane enclosed organelles - Bigger than bacterial cell (Eg:) plant and animal cells 🌱

Question 28

Where is DNA found?

Answer 28

Chromosomes or chromatin in the nucleus

Question 29

Vacuole function

Answer 29

To strengthen the cell and storage

Question 30

Experiment using a light microscope : Animal cell

Answer 30

Sample of cheek cells Stain using methylene blue 45° angle apply coverslip

Question 31

Animal cell: Ultrastructure contents

Answer 31

Cell membrane Nuclear membrane Nucleus (nucleolus, nuclear membrane, nuclear pores, chromatin) Ribosome Cytoplasm Mitochondria

Question 32

Plant cell: Ultrastructure contents

Answer 32

Cell membrane Cell wall Vacuole Nucleus (nucleolus, nuclear membrane, nuclear pores, chromatin) Cytoplasm Mitochondria Chloroplast