Chapter 5 - Cell Structure & Organisation

Question 1

Explain the cell theory

Answer 1

• All living things are composed of cells and cell products
• New cells are formed by cell division
• Cells contain genetic information used as instructions for growth and development
• Cells are the functioning units of life
• All chemical reactions of life happen inside cells

Question 2

Name 9 characteristics of a prokaryotic organism

Answer 2

• Extremely small (1-10 micrometers)
• No nucleus
• Small ribosomes (18 nm)
• Flagellum for movement
• No membrane bounded organelles
• DNA in circular loop
• Unicellular
• Cell surface membrane present
• No Endoplasmic Reticulum

Question 3

Name 9 characteristics of a eukaryotic organism

Answer 3

• Nucleus present
• Larger ribosomes (22 nm)
• No flagellum present
• Contain many membrane bounded organelles
• Endoplasmic Reticulum present
• Cell surface membrane present
• DNA located inside nucleus
• Multi- and unicellular
• Larger (10 - 100 micrometers)

Question 4

Name 6 characteristics of a plant cell

Answer 4

• Cell wall of cellulose present
• Contain chloroplasts
• Large, permanent vacuole present
• Regular shape
• Nucleus located more to the edge
• Larger in size

Question 5

Name 6 characteristics of an animal cell

Answer 5

• No cell wall
• No chloroplasts
• Small, non-permanent vacuoles
• Nucleus located at the center
• Irregular shape
• Smaller in size

Question 6

Name the functions of the cell surface membrane

Answer 6

• Control the entry and exit of substances
• Selectively permeable
• Maintains a constant internal environment

Question 7

Name the functions of the nucleus

Answer 7

• Controls all cell functions
• Produces an exact copy during cell division
• Passes on genetic information
• Site of transcription

Question 8

Name the functions of the nuclear envelope

Answer 8

• Contains pores to let out RNA and ribosomes

- Allows communication

Question 9

Name the functions of the nucleolus

Answer 9

• Ribosome synthesis

Question 10

Name the functions of the mitochondria

Answer 10

• Releases energy

- Produces ATP during respiration

Question 11

Name the functions of the chloroplasts

Answer 11

• Photosynthesis

Question 12

Name the functions of the cell wall

Answer 12

• Mechanical support
• Prevents bursting
• Helps to maintain shape
• Fully permeable

Question 13

Name the functions of the vacuole

Answer 13

• Stores salts, sugars, water and ions in cell sap

- Keeps plant cells turgid

Question 14

Name the functions of the tonoplast

Answer 14

• Surrounds the vacuole

- Controls entry and exit of substances

Question 15

Name the functions of the cytoplasm

Answer 15

• Metabolic pathways
• Most cellular activities occur in cytoplasm
• Site of translation

Question 16

Name the functions of the rough ER

Answer 16

• Transports mRNA from the nucleus to ribosomes

- Synthesis of ribosomes and proteins

Question 17

Name the functions of the smooth ER

Answer 17

• Synthesis of hormones and steroids

- Drug detoxification

Question 18

Name the functions of the golgi-body

Answer 18

• Processes molecules and proteins into packets

- Production of lysosomes

Question 19

Name the functions of the lysosomes

Answer 19

• Contains digestive enzymes

- Break down and destroy bacteria and unwanted organelles

Question 20

Name the function of the ribosomes

Answer 20

• Protein synthesis

Question 21

Name the function of the centrioles

Answer 21

• Forms spindle fibres during cell division

Question 22

State the function of the structure of the fatty acid tail in the phospholipid bilayer of the cell surface membrane

Answer 22

Maintains fluidity

Question 23

Name 5 protein molecules found in the cell surface membrane

Answer 23

• Spanning protein
• Embedded protein
• Surface protein
• Carrier protein
• Channel protein

Question 24

State two functions of carbohydrate chains found in the cell surface membrane

Answer 24

• Receptors for cell recognition

- Act as antigens during immune response

Question 25

Outline two functions of cholestrol molecules in the cell surface membrane

Answer 25

- Regulate fluidity | - Maintains stability

Question 26

Name four characteristics of the fluid mosaic model

Answer 26

- Reasonable suggestion based on existing knowledge - Phospholipids are liquids with fluidity - Protiens are afloat - Proteins are in a mosaic arrangement