B1 Cells

Question 1

What is resolution in imaging?

Answer 1

Ability to distinguish between 2 separate points in image

Question 2

What is magnification?

Answer 2

How much bigger an image compared to actual object

Question 3

What is the cell wall structure?

Answer 3

Outer layer of plant cells made of cellulose

Question 4

Where are proteins made?

Answer 4

Ribosomes

Question 5

What do chloroplasts contain?

Answer 5

Chlorophyll for photosynthesis

Question 6

What are the advantages of a light microscope?

Answer 6

Cheaper, easy to use, can observe live cells

Question 7

What are the advantages of an electron microscope?

Answer 7

Higher resolution, higher magnification, detailed views

Question 8

What are the disadvantages of a light microscope?

Answer 8

Low resolution, limited magnification

Question 9

What are the disadvantages of an electron microscope?

Answer 9

Complex preparation

Question 10

What is the maximum magnification of a light microscope?

Answer 10

x1500

Question 11

Why must specimens be dead for electron microscopy?

Answer 11

Process requires vacuum, so can’t observe living cells

Question 12

What is osmosis?

Answer 12

Movement of water molecules across a partially permeable membrane form an area of high water potential to an area of low water potential until equilibrium is reached

Question 13

What happens to an animal cell in a more dilute solution?

Answer 13

The cell gains water by osmosis and may burst. This is called lysis

Question 14

What happens to an animal cell in a more concentrated solution?

Answer 14

The cell loses water by osmosis and shrivels. This is called crenation

Question 15

Total magnification

Answer 15

Eyepiece lens x objective lens

Question 16

Active transport

Answer 16

Movement of substances low to high against a concentration gradient

Require energy from respiration ATP

Question 17

Why does active transport need carrier proteins in cell membrane

Answer 17

Bind to substance, change shape and transport it across membrane

Question 18

When is active transport used in gut

Answer 18

When there’s lower concentration of nutrients in the gut but higher concentration of nutrients in blood

Question 19

What happens when there’s higher concentration of glucose/amino acids in gut

Answer 19

They diffuse naturally into the blood

Question 20

When would concentration gradient be going the wrong way

Answer 20

When there’s a lower concentration of nutrients in the gut than in the blood

Question 21

When can glucose be taken into bloodstream

Answer 21

When its concentration in the blood higher than in gut

Question 22

Differences between diffusion, osmosis and active transport

Answer 22

Only active transport require energy

Only active transport requires carrier proteins

Only active transport movement of substance are low to high

Question 23

How osmosis differs from diffusion

Answer 23

Osmosis is movement of water across partially permeable membrane from area of high water potential to area of lower water potential.

Diffusion is movement of molecules and doesn’t require membrane

Question 24

Similarities diffusion, osmosis

Answer 24

Both passive

Both involve movement down a concentration gradient

Question 25

What happens to a plant cell when it is placed in a more DILUTE solution?

Answer 25

Cell gains water by osmosis but does not burst This cell is now turgid.

Question 26

Why does a plant cell not burst when it is placed in a more dilute solution?

Answer 26

Cell wall

Question 27

What happens to an plant cell when it is placed in a more CONCENTRATED solution?

Answer 27

The cell loses water by osmosis. The cell membrane pulls away from the cell wall. This is is called plasmolysis.

Question 28

Give an example of molecules that move by active transport.

Answer 28

Mineral ions in soil enter root hair cells

Question 29

Describe how mineral ions enter root hair cells from the soil

Answer 29

Mineral ions absorbed into root hair cells by active transport Which moves ions from a low concentration in the soil to high concentration in root hair cells This process requires energy from respiration and involves carrier proteins in cell membrane

Question 30

How do you calculate % change in mass

Answer 30

(Final mass - initial mass) ÷ (initial mass) x 100

Question 31

Prokaryotic cell

Answer 31

Simple cell without nucleus and membrane bound organelles

Question 32

Eukaryotic cell

Answer 32

Complex cell with nucleus and membrane bound organelles

Question 33

Prokaryotic cells examples

Answer 33

Bacteris, Archaea

Question 34

Eukaryotic cells examples

Answer 34

Plant cells, animal cells, fungal, protists

Question 35

Differences between prokaryotic and eukaryotic cells

Answer 35

Prokaryotic has no nucleus, eukaryotic does Prokaryotic cells are smaller Prokaryotic cells have smaller ribosomes

Question 36

Prokaryotic cells size

Answer 36

0.1-5 hm

Question 37

Euakrayotic size

Answer 37

10-100 hm

Question 38

Prokaryotic cells divide

Answer 38

Binary fission

Question 39

Eukaryotic cells divide

Answer 39

Mitosis

Question 40

What type of DNA do prokaryotic cells have?

Answer 40

1 circular chromosome, NOT enclosed by a nucleus.

Question 41

What type of DNA do eukaryotic cells have?

Answer 41

Many linear chromosomes enclosed by a nucleus

Question 42

Flagella

Answer 42

Helps movement

Question 43

Plasmids

Answer 43

Small circular DNA molecules that carry extra genes

Question 44

What is the function of sperm cells?

Answer 44

Fertilise egg during sexual reproduction

Question 45

What is the function of nerve cells?

Answer 45

Transmits electrical impulses.

Question 46

What is the function of muscle cells?

Answer 46

Contract quickly to move bones

Question 47

How are sperm cells adapted for their function?

Answer 47

Streamlined head and long tail to aid swimming Many mitochondria supply energy to allow cell to move The acrosome (top of the head) has digestive enzymes which break down outer layers of membrane of the egg cell

Question 48

How are nerve cells adapted for their function?

Answer 48

The axon is long, enabling the impulses to be carried along long distances Nerve endings have many mitochondria which supply energy to make neurotransmitters

Question 49

How are muscle cells adapted for their function?

Answer 49

Special proteins slide over each other, causing the muscle to contract Lots of mitochondria provide energy from respiration for contraction Can store glycogen used in respiration

Question 50

What is the function of xylem cells in a plant?

Answer 50

Transport water and mineral ions up the plant from roots to shoots.

Question 51

What is the function of phloem cells in a plant?

Answer 51

Transports food (by translocation) from the leaves to other parts of the plant.

Question 52

How are xylem cells adapted for their function?

Answer 52

Xylem cells hollow and joined end-to-end to form a continuous tube so water and mineral ions can move through Lignin helps cell walls which help withstand pressure water

Question 53

How are phloem cells adapted for their function?

Answer 53

Have few organelles so food can move faster Have companion cell with mitochondria to supply energy Cell walls of each phloem cell form sieve plates when they break down, allowing the movement of substances from cell to cell

Question 54

Cover slip used for

Answer 54

Flatten sample and protect microscope lens

Question 55

Staining (drop of iodine) used for

Answer 55

Highlight specific cell structures

Question 56

Why add drop of water

Answer 56

Prevent specimen from drying out and transparency

Question 57

Why cover slip lowered 45° angle

Answer 57

Avoid trapping air bubbles

Question 58

Why press down cover slip

Answer 58

To spread sample evenly ensure thin enough for light to pass through

Question 59

Coarse adjustment knob

Answer 59

Bring specimen to rough focus

Question 60

Fine adjustment knob

Answer 60

Gives clearer image

Question 61

Diaphragm

Answer 61

Controls amount of light reaches specimen