chapter 2- Organisation of the organism

Question 1

Plant and animal cells both have:

Answer 1

• nucleus
• cytoplasm
• cell membrane

Question 2

Nucleus

Answer 2

• Contains genetic material (DNA)
• controls activities and characteristics of cell
  -Chromosomes visible during cell division

Question 3

Cytoplasm

Answer 3

-Contains water and dissolved substances
-Contains mitochondria for aerobic respiration
-Rough endoplasmic reticulum (rER) to make proteins

Question 4

Cell membrane

Answer 4

• Surround cytoplasm
• Controls entry and exit of dissolved substances
• Forms barrier between cell and surroundings

Question 5

plants also have

Answer 5

• chloroplasts, vacuole, cell wall

Question 6

Chloroplasts

Answer 6

• Packed with chlorophyll
  -Contain enzymes to produce glucose through photosynthesis

Question 7

Vacuole

Answer 7

-Contains water
- Provides turgor pressure to maintain the shape of the cell
- Filled with cell sap

Question 8

Cell wall

Answer 8

Protects and supports the cell

Question 9

Which organisms do not have mitochondria and rER?

Answer 9

• Prokaryotes

Question 10

What adaptation do high-energy cells (such as muscle) have?

Answer 10

• Need more energy, so have more mitochondria

Question 11

Tissue

Answer 11

of cells of similar structure working together to perform the same function

Question 12

Organ

Answer 12

collection of different tissues working together to perform specific function

Question 13

Organ system

Answer 13

group of organs with related functions working together to perform body functions

Question 14

Red blood cell

Answer 14

• Function: transport oxygen around the body for respiration
• Contains haemoglobin which binds to oxygen forming oxyhaemoglobin
• Biconcave disc shape increases surface area to volume ratio
• Very flexible enabling it to pass through small vessels
• No nucleus - more room for haemoglobin so more oxygen can then be transported

Question 15

Muscle cell

Answer 15

• Function: to contract and relax in order to move muscles
• Cells are long
• Contain many protein fibres
• Protein fibres can shorten the cell when energy is available
• This makes the cell able to contract

Question 16

Ciliated cell

Answer 16

• Function: move mucus out of the trachea and bronchi
• Have layer of tiny hairs (cilia)
• Cilia can move and push mucus
• Mucus traps dust and microbes
• Mucus is expelled

Question 17

Motor nerve cell

Answer 17

• Function: conduct impulses
• Long fibre called an axon
• Axon can carry electrical impulses
• Axons have a fatty sheath to insulate
• Many branched ending can connect with other cells

Question 18

Sperm cell

Answer 18

• Function: reproduction
• Haploid nucleus
• Flagellum beats to swim cell towards ovum
• Acrosome contains enzymes to penetrate egg cell
• Mitochondria in cytoplasm release energy for movement

Question 19

Egg cell (ovum)

Answer 19

• Function: reproduction
• Haploid nucleus
• Jelly coat changes at fertilization
• Allows entry of male nucleus

Question 20

Root hair cell

Answer 20

• Function: absorption
• Long extension called root hair
• Large surface area
• For absorption of water by osmosis
• For absorption of mineral ions by active transport

Question 21

Xylem vessel

Answer 21

• Function: transport and support
• No end wall, so many cells can form a tube
• No cytoplasm, so water can pass freely
• Coated with lignin to strengthen and support plant
• Transports mineral ions and water from roots upwards

Question 22

Palisade mesophyll

Answer 22

• Function: photosynthesis
• Contains many chloroplasts to absorb light
• Tall thin cells - densely packed
• Maximises photosynthesis

Question 23

How do you calculate magnification?

Answer 23

Magnification = measured length/ actual length

Question 24

How do you calculate Actual (true) length?

Answer 24

Actual length = Measured length / magnification