Cell structures

Question 1

spell out in your head the 2 basic types of cells

Answer 1

prokaryotic cells and eukaryotic cells

Question 2

what is an example of a prokaryotic cell?

Answer 2

bacteria

Question 3

what are eukaryotic cells?

Answer 3

plants, animals, fungi and protoctista

Question 4

important features of prokaryotic cells

Answer 4

1. small and unicellular
2. has a peptidoglycan cell wall
3. does not have membrane-bound organelles
4. nucleoid contains DNA
5. does not have a nucleus

Question 5

what are the structures present in prokaryotic cells?

Answer 5

important
1. peptidoglycan cell wall
2. cell surface membrane
3. nucleoid
4. ribosomes
5. cytoplasm
unimportant
5. pili (pilus for singular)
6. flagella (flagellum for singular)
7. food granule
8. plasmid
9. mesosome

Question 6

differences between plant and animal cells

Answer 6

A plant cell has a cellulose cell wall but an animal cell does not.
A plant cell has a large permanent vacuole but an animal cell has small temporary vacuoles.
A plant cell has chloroplast but an animal cell does not.

Question 7

similarities between plant and animal cells

Answer 7

both of them have cell surface membrane, golgi apparatus, mitochondrion, ribosomes, smooth and rough endoplasmic reticulums, nucleus, nucleolus, nuclear envelope

Question 8

what is the role of a cell surface membrane?

Answer 8

it is an extremely thin structure that consists of lipid bilayer in which proteins are embedded.
can form vesicles.

functions:
retains cytosol
forms a barrier across which all substances entering and leaving the cell must pass.

Question 9

what is the role of a nucleus?

Answer 9

largest organelle
it contains chromosomes that are made up of DNA and protein.
function:
involved in cell management and its behaviour when cell divides

Question 10

what is the role of a nuclear envelope?

Answer 10

the nucleus is surrounded by a double membrane, known as nuclear envelope.

function:
the nuclear envelope contains many pores that allow movement of molecules between nucleus and cytoplasm.

Question 11

what is the role of a nucleolus?

Answer 11

a tiny, rounded, darkly-staining body.

function:
it is the site where ribosomes are synthesized.

Question 12

what is the role of rough endoplasmic reticulum?

Answer 12

has ribosomes attached to the outer surface
function:
ribosomes on the rER are the sites of synthesis of proteins that are packaged into vesicles.

Question 13

what is the role of smooth endoplasmic reticulum?

Answer 13

no ribosomes
function:
site of synthesis of lipids and steroids, and the reproductive hormones
site of storage of calcium ions in muscle fibres

Question 14

role of Golgi apparatus?

Answer 14

functions:
site of synthesis of specific biochemicals, such as hormones and enzymes
activates proteins by adding sugars or removing amino acid

Question 15

role of mitochondrion?

Answer 15

has a double membrane
contains ribosomes
function: site of aerobic respiration and the synthesis of adenosine triphosphate (ATP)

Question 16

spell out the full spelling of ATP in your head

Answer 16

adenosine triphosphate

Question 17

role of ribosomes?

Answer 17

found free in the cytosol or bound to the ER
function:
sites where proteins are synthesised in cells

Question 18

role of vesicles?

Answer 18

they store and transport substances around the cells.

Question 19

role of chloroplasts?

Answer 19

large organelle
occur only in plant cells
has a double membrane
function:
site of photosynthesis by which light is used as the energy source in carbohydrate and adenosine triphosphate (ATP) synthesis.

Question 20

role of cellulose cell wall?

Answer 20

fully permeable
occur only in plant cells
function:
enclose, support and protect cells

Question 21

role of large, permanent vacuole?

Answer 21

stores nutrients, absorbs water

Question 22

role of small, temporary vacuole?

Answer 22

temporary stores of food/water

Question 23

role of cytoplasm?

Answer 23

site where substances are formed and used in chemical reactions of life

Question 24

differentiate cell, tissue, organ, system

Answer 24

a group of cells work together to form a tissue.
different tissues combine to form an organ.
several organs work together to make up an organ system.
various organ systems work together to make up an organism.

Question 25

how does the cell structure relate to the function of red blood cells?

Answer 25

the cell surface membrane contains haemoglobin, which binds to oxygen and transports it around the body.

the red blood cell is circular and biconcave in shape to increase surface area to volume ratio for faster diffusion.

the red blood cell lacks a nucleus in order to store more haemoglobin for transportation of oxygen

Question 26

how does the cell structure relate to the function of root hair cells?

Answer 26

the long and narrow root hair/extension increases surface area to volume ratio for faster osmosis of water molecules and diffusion of mineral salts in and out of the cell, allowing it to absorb more water and mineral salts faster.

Question 27

how does the cell structure relate to the function of xylem vessels?

Answer 27

xylem vessels only have a cellulose cell wall (dead tissue, no cell content)

The long hollow and continuous tubes without cross-walls allows the xylem to transport water from roots to leaves with no obstructions.

Lacks protoplasm, so that there is no resistance to water flow.

Walls are thickened with lignin to provide structural/mechanical support and prevents collapse of vessel during transport of water.