Cells

Question 1

Light Microscopes

Answer 1

• 1000x

- coloured images

Question 2

Electron microscopes

Answer 2

• 200 000x

- Black and white images (can be artificially colourised)

Question 3

Cell surface membrane

Answer 3

• plasma membrane
• surrounds cytoplasm
• made up of lipids and proteins
• partially permeable

Question 4

Cytoplasm

Answer 4

• where most cell activities occur

- carries many organelles ie. mitochondria, centrioles, ribosomes

Question 5

Nucleus

Answer 5

• controls cell activites ie. cell growth

- essential for cell division

Question 6

Nucleoplasm

Answer 6

• small round mass of denser protoplasm

- in nucleus

Question 7

Nuclear envelope

Answer 7

• membrane surrounding nucleoplasm

Question 8

Cell wall

Answer 8

• surrounds plants’ cell surface membrane
• made up of cellulose
• protects frm injury
• fixed shape
• fully permeable

Question 9

Nucleolus

Answer 9

• protein synthesis

Question 10

Chromatin

Answer 10

• long thread-like structures
• histone proteins and DNA (hereditary info)
• cell division: threads condense, become highly coiled chromosomes

Question 11

Rough endoplasmic reticulum (RER)

Answer 11

• network of fluid-filled flattened spaces
• lined with membrane
• ribosomes attached to outer surface
• outer surface continuous with nuclear envelope

Question 12

Ribosomes

Answer 12

• round small structures
• make proteins
• attached to ER: usually transported out of cell
• lying freely in cytoplasm: used within cytoplasm of cell

Question 13

Smooth endoplasmic reticulum (SER)

Answer 13

• no ribosomes attached
• more tubular than RER
• connected to RER
• synthesises fats and steroids (hormones)
• converts harmful substances to harmless (detoxification)

Question 14

Golgi Apparatus

Answer 14

• stack of flattened spaces
• surrounded by membrane
• chemically modifies substances frm ER
• stores and packages substances in vesicles for secretion out of cell

Question 15

Vesicles (How they are transported)

Answer 15

1. small vesicles containing substances pinched off from ER
2. vesicles fuse with and release contents into Golgi Apparatus, may be modified
3. secretory vesicles containing modified substances pinched off, move to cell surface membrane
4. Fuses with cell surface membrane, contents released out of cell

Question 16

Mitochondria

Answer 16

• aerobic respiration occurs here
• food substances oxidised to release energy
• energy used for cellular activities e.g. growth, reproduction

Question 17

Chloroplasts

Answer 17

• contain green pigment chlorophyll

- photosynthesis

Question 18

Vacuoles

Answer 18

• fluid-filled space enclosed by membrane
• animal cells: numerous, small, temporary, water&food
• plant cells: large central vacuole, cell sap (dissolved sugars, mineral salts, amino acids), surrounded by tonoplast