Cell Boilogy

Question 1

What are two types of eukaryotic cell?

Answer 1

Animal and plant

Question 2

What type of cell are bacteria?

Answer 2

Prokaryotic

Question 3

Where is DNA found in animal and plant cells?

Answer 3

In the nucleus

Question 4

What is the function of the cell membrane?

Answer 4

Controls movement of substances in and out of the cell

Question 5

What is the function of mitochondria?

Answer 5

Site of respiration to transfer energy for the cell

Question 6

What is the function of chloroplasts?

Answer 6

Contain chlorophyll to absorb light energy for photosynthesis

Question 7

What is the function of ribosomes?

Answer 7

Enable production of proteins (protein synthesis)

Question 8

What is the function of the cell wall?

Answer 8

Strengthens and supports the cell

Question 9

What is the structure of the main genetic material in a prokaryotic cell?

Answer 9

Single loop of DNA

Question 10

How are electron microscopes different from light microscopes?

Answer 10

Of light, cannot be used to view living samples, are much more expensive, and have a much higher magnification and resolution

Question 11

What is the function of a red blood cell?

Answer 11

Carries oxygen around the body

Question 12

Give three adaptations of a red blood cell.

Answer 12

• No nucleus
• Contains a red pigment called haemoglobin
• Has a bi-concave disc shape

Question 13

What is the function of a nerve cell?

Answer 13

Carries electrical impulses around the body

Question 14

Give two adaptations of a nerve cell.

Answer 14

• Branched endings
• Myelin sheath insulates the axon

Question 15

What is the function of a sperm cell?

Answer 15

Fertilises an ovum (egg)

Question 16

Give two adaptations of a sperm cell.

Answer 16

• Tail
• Contains lots of mitochondria
  Streamlined head

Question 17

What is the function of a palisade cell?

Answer 17

Carries out photosynthesis in a leaf

Question 18

Give two adaptations of a palisade cell.

Answer 18

• Lots of chloroplasts
• Located at the top surface of the leaf

Question 19

What is the function of a root hair cell?

Answer 19

Absorbs minerals and water from the soil

Question 20

Give two adaptations of a root hair cell.

Answer 20

• Long projection
• Lots of mitochondria

Question 21

What is diffusion?

Answer 21

Net movement of particles from an area of high concentration to an area of low concentration along a concentration gradient

Question 22

Name three factors that affect the rate of diffusion.

Answer 22

• Concentration gradient
• Temperature
• Membrane surface area

Question 23

How are villi adapted for exchanging substances?

Answer 23

• Long and thin - increases surface area
• One-cell-thick membrane - short diffusion pathway
• Good blood supply - maintains a steep concentration gradient

Question 24

How are the lungs adapted for efficient gas exchange?

Answer 24

• Alveoli - large surface area
• Moist membranes - increases rate of diffusion
• One-cell-thick membranes - short diffusion pathway
• Good blood supply - maintains a steep concentration gradient

Question 25

How are vili adapted for efficient gas exchange?

Answer 25

* Large surface area for gases to diffuse across * Thin layer of cells - short diffusion pathway * Good blood supply - maintains a steep concentration gradient

Question 26

What is osmosis?

Answer 26

Diffusion of water from a dilute solution to a concentrated solution through a partially permeable membrane

Question 27

Give one example of osmosis in a plant.

Answer 27

Water moves from the soil into the root hair cell

Question 28

What is active transport?

Answer 28

Movement of particles against a concentration gradient using energy from respiration

Question 29

Why is active transport needed in plant roots?

Answer 29

Concentration of mineral ions in the soil is lower than inside the root hair cells

Question 30

What is the purpose of active transport in the small intestine?

Answer 30

Sugars can be absorbed when the concentration of sugar in the small intestine is lower than the concentration of sugar in the blood

Question 31

What type of cells are bacteria cells Prokaryotic/eukaryotic

Answer 31

Prokaryotic

Question 32

Prokaryotic cells are much _________ than eukaryotic cells and have a cell wall, cell ___________ and cytoplasm but do not have a nucleus, mitochondria or chloroplasts.

Answer 32

Smaller Membrane

Question 33

Prokaryotic cells have a __________ ___________ _____ _______ and several small rings of DNA called ______ , which are free inn the cytoplasm. Some bacteria cells have a slime capsule for ___________and a flagella to help them -________

Answer 33

Single loop of DNA Plasmids Protection Move

Question 34

Job of xylem

Answer 34

Transport water and minerals around the body

Question 35

Job of phloem

Answer 35

Transports sugar in stem

Question 36

Adaptations of phloem

Answer 36

Have sieve plates kept alive by companion cells

Question 37

Adaptations of xylem (3)

Answer 37

-hollow tubes -strong to support stem -cell wall with lignin (dead)

Question 38

Is xylem in a plant or an animal

Answer 38

Plant

Question 39

Is phloem in a plant or an animal

Answer 39

Animal

Question 40

Explain how to change the magnification on a light microscope

Answer 40

First change the magnification power of the objective lens by switching to a higher lens.

Question 41

Explain how to focus the image on a light microscope

Answer 41

Use the course focussing knob and then the fine focussing knob to bring the image into focus

Question 42

What do we add to onion skin when looking at it under a light microscope

Answer 42

Coloured dye , iodine

Question 43

Magnification measurements How to go from a centimetre to a millimetre

Answer 43

Times by 10

Question 44

Units of measurement magnification How do you get from a micrometer to a millimetre

Answer 44

Divide by 1000

Question 45

Units of measurement magnification How do you get from a nanometre to a micrometer

Answer 45

Divide by 1000

Question 46

Formula for calculating cell magnification from images

Answer 46

Magnification = image size/ actual size

Question 47

Describe the 4 steps of mitosis

Answer 47

1. Chromosomes are replicated 2. Each pair of chromosomes is pulled apart to opposite sides of the cell 3. DNA replicated 4. Cytoplasm and cell membrane divide to form 2 genetically identical cells

Question 48

2 types of stem cells

Answer 48

Embryonic Adult

Question 49

What can stem cells be used for?

Answer 49

- treat blood illnesses : lekimia - cancer in the bone marrow - personalise medicine - replace damaged organs

Question 50

Definition embryonic stem cells

Answer 50

Embryonic stem cells can develop onto all different types of cells in the body

Question 51

Definition adult stem cells

Answer 51

Adult stem cells can only develop into a limited number of cells

Question 52

Definition of stem cells

Answer 52

Stem cells are unspecialised cells that can differentiate into many different cell types

Question 53

What is the test for sugar?

Answer 53

Benedict’s warm turns red/orange

Question 54

What are the four functions of a skeleton

Answer 54

Protect Support Move make blood- red blood cells, platelets, white blood cells

Question 55

What are the small air sacs in your lungs

Answer 55

Alveloli

Question 56

What part of a skeleton makes blood cells

Answer 56

Bone marrow

Question 57

What is the test for starch

Answer 57

Iodine turns black

Question 58

What is the test for protein

Answer 58

Biurets reagent turns lilac

Question 59

Which enzyme breaks down sugar

Answer 59

Amylase

Question 60

Which enzyme breaks down starch

Answer 60

Carbohydrase / amylase

Question 61

Which enzyme breaks down protein

Answer 61

Protease

Question 62

Which enzyme breaks down. Fats

Answer 62

Lipase

Question 63

Formula for anaerobic respiration

Answer 63

Human Glucose - lactic acid +energy Other Glucose - carbon dioxide +ethonal + energy

Question 64

Formula for areobic respiration

Answer 64

Glucose + oxygen - carbon dioxide + water

Question 65

True or false An organ is only made up of 1 type of tissue

Answer 65

False

Question 66

What is the substance that fills the vacuole and what does it do

Answer 66

Cell sap - storage of materials - mechanical support

Question 67

Why are cultures in microorganisms kept at 25 degrees Celsius in school labs?

Answer 67

Harmful pathogens are unlikely to grow at this temperature

Question 68

Give one way which you could prevent a bacterial culture from becoming contaminated with unwanted microorganisms.

Answer 68

Sterling the Petri dish

Question 69

True or false ‘all plant cells lose their ability to differentiate at an early stage

Answer 69

False

Question 70

What happens inside a cell before mitosis takes place

Answer 70

The number of sub cellular structures doubles

Question 71

Explain why root hair cells in plants might use active transport ? 4 marks

Answer 71

The concentration of mineral ions in the soil is ussally lower than inside the root cells ( 1 mark ) So the mineral ions won’t diffuse into the cells ( 1 mark ) However plants need the mineral ions for a healthy growth ( 1 mark ) So they use active transport to absorb the mineral ions against the concentration gradient ( 1 mark )