Cells

Question 1

Cells structure

Answer 1

Living organisms are made of cells

Question 2

How are Animal cells like

Answer 2

Multicellular
Cells containing nucleons with distinct membrane
No cellulose walls
No chloroplasts
Feed organic substances made by living things
Able to move from place to place, have nervous coordination

Question 3

How are plant cells

Answer 3

Multicellular
Contain nucleus with distinct membrane
Contain chloroplasts (to carry out photosynthesis)feed by photosynthesis
Store carbohydrates as starch or sucrose
No nervous coordination

Question 4

Nucleus function (both animal and plant)

Answer 4

Contain genetic material (dna) which controls cell activities

Question 5

Cytoplasm (both animal and plant)

Answer 5

Gel like substance composed of water and dissolved solutes
Support internal cell structures
Site of many chemical reactions including anaerobic respiration

Question 6

Cell membrane (both animal and plant)

Answer 6

Holds cell together, separating inside from outside
Controls which substance can enter and leave the cell

Question 7

Cell membrane (both animal and plant)

Answer 7

Holds cell together, separating inside from outside
Controls which substance can enter and leave the cell

Question 8

Ribosomes (both animal and plant)

Answer 8

Found in the cytoplasm
site of protein synthesis

Question 9

Mitochondria (both animal and plant)

Answer 9

Site of most of the reactions involving aerobic respiration, where energy is released to fuel cellular processes
Cell with high rates of metabolism( carrying many different cell reactions) significantly have higher numbers of mitochondria than cells with fewer reactions taking place

Question 10

Cell wall (only plant)

Answer 10

Made of cellulose (polymer of glucose)

Question 11

Chloroplasts

Answer 11

Containing green chlorophyll pigments (to absorb light energy) and the enzymes needed for photosynthesis

Question 12

Permanent vacuole

Answer 12

Contains SAP: solution of sugars and salts dissolved in water
Used for storage of certain materials
Also helps support cells shape

Question 13

Magnification equation

Answer 13

Magnification = image size / actual size

Question 14

Movement in and out of cells
Diffusion

Answer 14

Te movement of particles form a region of their higher concentration to a region of their lower concentration down a concentration gradient, as a result of random movement

Question 15

Movement in and out of cells
Diffusion

Answer 15

Te movement of particles form a region of their higher concentration to a region of their lower concentration down a concentration gradient, as a result of random movement

Question 16

Factors influencing diffusion

Answer 16

Surface area to volume ratio
Distance
Temperature
Concentration gradient

Question 17

How does Diffusion occur across cell membrane

Answer 17

Substance move in and out of cells by diffusion through cell membrane, cell membrane partially permeable meaning it allows some molecules to cross easily, but other with difficulties or not at all

Question 18

Osmosis

Answer 18

The net movement of particles in and out of cells from region of higher water potential (dilute solution) to a region of lower water potential (concentrated solution through partially permeable membrane) through cell membrane

Question 19

What happens when plant are placed in solution with higher potential energy than inside the cell?

Answer 19

Water moves into the cells via osmosis
Water molecules push the cell membrane against cell wall increasing the TURGOR PRESSURE in the cells making them TURGID

Question 20

What happens to cells placed in a concentrated solution with lower water potential than inside cells?

Answer 20

Molecules move out of plant cells by osmosis, making them flaccid
Flaccid cells can negatively affect plants ability to support itself
Cell Underneath a microscope might look PLASMOLYSED

Question 21

Immersing plant cells in solutions with different concentrations

Answer 21

1. Cut cylinders of root vegetables (potatoes or radish) placing them into distilled water and sucrose solutions of increasing concentration
2. Cylinders are weighed before placing into solution
3. Leave in solution for 20-30 minutes and then removed, dried to remove excess liquid and reweighed

Question 22

What happens if plant tissue gains mass

Answer 22

Water must’ve moved into plant tissue from solution surrounding it via osmosis
Solution surrounding tissue more dilute than plant tissue

Question 23

What happens if plant tissue loses mass

Answer 23

Water must’ve moved out of plant tissue into solution surrounding it via osmosis
Tissue’s Surrounding solution more concentrated than plant tissue

Question 24

What does it mean if there’s no overall change in mass

Answer 24

No net movement of water as the concentration in both plant tissue and solution surrounding it must be equal
Note that water will still be moving into and out of plant tissue, but no net movement in this case

Question 25

What happens when water moves into a plant cell?

Answer 25

Vacuole Gets bigger, pushing cell membrane against cell wall
Water enetering the cell via osmosis makes cell rigid and firm

Question 26

Why is this important for plants?

Answer 26

• The effect of all cells in a plant being rigid providing support and strength for the plant, making the plant test and upright with leaves held out to catch sunlight
• Pressure created by cell wall stops too much water from entering preventing cell from bursting
  If they do not receive enough water, cell cannot remain rigid and firm (turgid)

Question 27

What’s the importance of water potential on animals cells and tissues?

Answer 27

Animal cells :
- in solution they lose and gain water in result of osmosis
- do not have supporting cell wall
- if placed into sugar solution (with lower water potential than cell) it will lose water by osmosis becoming cremated (shriveled up)
-if placed into distilled water it will gain water by osmosis and since it doesn’t have cell wall creates turgor pressure, and will continue to do so until cell membrane is stretched to far an bursts