Topic 1- Cell Biology

Question 1

What are the two types of cells?

Answer 1

Prokaryotic, eukaryotic

Question 2

In what are eukaryotes found?

Answer 2

Plant and animal cells

Question 3

What is the difference between eukaryotes and prokaryotes?

Answer 3

Eukaryotic cells are bigger

Eukaryotic cells contain membrane-bound organelles and a nucleus

Question 4

What does DNA form in the nucleus?

Answer 4

Chromosomes

Question 5

In what can you find prokaryotes

Answer 5

Bacteria (single celled organism)

Question 6

Where is the DNA found in a prokaryote?

Answer 6

Chromosomal DNA (single loop)

Plasmid DNA

Question 7

What feature to some prokaryotes have to help move them around?

Answer 7

Flagella (tails)

Question 8

Nucleus

Answer 8

Controls activity, contains genes to build new cells

Question 9

Cytoplasm

Answer 9

Liquid gel where chemical reactions take place

Question 10

Cell membrane

Answer 10

Controls passage into or out of cell

Question 11

Mitochondria

Answer 11

Where aerobic respiration takes place (powerhouse of the cell)

Question 12

Ribosomes

Answer 12

Where protein synthesis takes place

Question 13

Cell wall

Answer 13

Strengthens and supports cell

Prevents cell bursting when water enters by osmosis

Question 14

Chloroplasts

Answer 14

Contain chlorophyll and absorbs light for photosynthesis

Question 15

permanent vacuole

Answer 15

In cytoplasm filled with sap, keeps cell rigid

Question 16

What are plasmids?

Answer 16

Small loops of DNA found free in the cytoplasm

Question 17

List the components found in both plant and animal cells (5)

Answer 17

Cell membrane
Nucleus 
Cytoplasm 
Mitochondria
Ribosomes

Question 18

List the components plant cells have that animal cells don’t (3)

Answer 18

Cell wall
Chloroplasts
Permanent vacuole

Question 19

What is the cell wall made of?

Answer 19

Cellulose

Question 20

What is the cell wall made of?

Answer 20

Cellulose

Question 21

How are sperm cells specialised?

Answer 21

Tail (enables movement)
Mitochondria (provide energy for tail movement)
Haploid nucleus (contains genetic info)
Acrosome (enzymes that digest egg cell membrane)

Question 22

How are nerve cells specialised?

Answer 22

Dendrites (connect to and receive impulses from other nerve cells, muscles + glands)
Long axon (allows electrical impulses to be transmitted all over body from CNS)

Question 23

How are muscles cells specialised ?

Answer 23

Mitochondria (energy for muscles contraction)
Arrangement of protein filaments (slide over each other for muscle contraction)
Merged cells (allow muscle fibre contraction)

Question 24

How are root hair cells specialised?

Answer 24

Large surface area (absorb nutrients and water from surrounding soil)
Thin walls (don’t restrict water absorption)

Question 25

How are xylem cells specialised?

Answer 25

No margins between cells (continuous route for water to flow) Thick side walls (strengthen structure and prevent collapses)

Question 26

How are phloem cells specialised?

Answer 26

``` Sieve plates (dissolves sugars transported up and down stem) Companion cells (energy for active transport of substances) ```

Question 27

What is cell differentiation

Answer 27

The process in which cells become specialised

Question 28

Why is cell differentiation important?

Answer 28

Allows production of different tissues to do different functions in body

Question 29

When in life do animal cells differentiate

Answer 29

Early life

Question 30

When do plant cells differentiate?

Answer 30

Throughout their lives

Question 31

What is the purpose of cell division in mature animals?

Answer 31

Repair and replacement of cells

Question 32

How do bacteria multiply?

Answer 32

Binary fission

Question 33

What are chromosomes made of?

Answer 33

DNA molecules and proteins.

Question 34

What is a gene?

Answer 34

A section of DNA which codes for a protein

Question 35

How many chromosomes are found in the nucleus of a human body cell?

Answer 35

46

Question 36

How many chromosomes are found in the nucleus of human gametes?

Answer 36

23

Question 37

What are the 3 main stages of the cell cycle?

Answer 37

1. Replication of DNA 2. Mitosis 3. Division of cell

Question 38

Why is mitosis important?

Answer 38

Produces identical cells with the same genetic info | Produces additional cells for growth and repair

Question 39

What is a stem cell?

Answer 39

An unspecialised cell which can differentiate into other cell types and self renewal

Question 40

What is diffusion?

Answer 40

The net movement of particles from an area of higher concentration to lower concentration

Question 41

What 3 factors affect the rate of diffusion?

Answer 41

Concentration gradient Temperature Surface area

Question 42

How are singe celled organisms adapted for diffusion

Answer 42

Large surface area to volume ratio- maximises rate of diffusion

Question 43

What 4 factors increase effectiveness of gas exchange surface?

Answer 43

Large surface area Thin membrane (short diffusion path) Efficient blood supply Ventilation

Question 44

What is osmosis?

Answer 44

The net movement of water particles from a diluted solution to a concentrated solutions through a partially permeable membrane

Question 45

What is active transport?

Answer 45

Movement of molecules from a dilute solution to a concentrated solution against a concentration gradient, using energy from respiration

Question 46

How do root hair cells use active transport?

Answer 46

Take up mineral ions from a more dilute solution in soils