Unit 1

Question 1

list the structures found in a typical animal cell

Answer 1

• cell membrane
• cytoplasm
• nucleus
• mitochondria
• ribosomes

Question 2

list the structures found in a typical plant cell

Answer 2

• cell wall
• cell membrane
• cytoplasm
• nucleus
• mitochondria
• ribosomes
• chloroplasts
• vacuole

Question 3

list the structures found in a typical fungal cell

Answer 3

• cell wall
• cell membrane
• cytoplasm
• nucleus
• mitochondria
• ribosomes

Question 4

list the structures found in a typical bacterial cell

Answer 4

• cell wall
• cell membrane
• cytoplasm
• ribosomes
• chromosomal DNA
• plasmid DNA

Question 5

what is the role of cytoplasm?

Answer 5

to be the place where chemical reactions happen

Question 6

what is the role of the cell membrane?

Answer 6

keeps the cell together and provides a barrier to what enters and exits the cell

Question 7

what is the role of the nucleus?

Answer 7

contains cell DNA and controls all the events in the cell

Question 8

what is the role of mitochondria?

Answer 8

release chemical energy from rood (respiration)

Question 9

what is the role of ribosomes?

Answer 9

to make proteins

Question 10

what is the role of the cell wall?

Answer 10

to provide structure to the cell

Question 11

what is the role of chloroplasts?

Answer 11

to carry out photosynthesis

Question 12

what is the role of vacuoles?

Answer 12

to contain sap

Question 13

how are the walls of bacteria and fungi different to the cell wall of plants?

Answer 13

they are not made of cellulose

Question 14

what are plasmids?

Answer 14

small circular sections of DNA

Question 15

what is the cell membrane made of?

Answer 15

phospholipids and proteins

Question 16

the cell membrane is selectively permeable, what does that mean?

Answer 16

it allows some but not all substances across it and chooses which substances can enter and exit the cell

Question 17

what is passive transport?

Answer 17

movement of substances down a concentration gradient ( does not require energy)

Question 18

what is diffusion?

Answer 18

movement of molecules down a concentration gradient

Question 19

list 3 substances that can diffuse in and out of a cell

Answer 19

• glucose
• carbon dioxide
• oxygen
• amino acids
• urea

Question 20

what is osmosis?

Answer 20

the movement of molecules from a high water concentration to a lower water concentration through a selectively permeable membrane

Question 21

when they absorb too much water what happens to animal cell?

Answer 21

bursts

Question 22

when they absorb too much water what happens to plant cell?

Answer 22

becomes turgid

Question 23

when they do not contain enough water what happens to a plant cell?

Answer 23

becomes plasmolysed

Question 24

when they do not contain enough water what happens to a plant cell?

Answer 24

shrinks

Question 25

why does active transport require energy?

Answer 25

for membrane proteins to move molecules or ions against the concentration gradient

Question 26

give an example of active transport

Answer 26

sodium and potassium in nerve cells or iodine in seaweed

Question 27

what is mitosis?

Answer 27

cell division which produces 2 cells with the same number of chromosomes as the original cell

Question 28

describe the stages of mitosis

Answer 28

- each chromosome replicates to form 2 identical chromotids and the nuclear membrane begins to break down - chromosomes line up along equator and spindle fibres join on to them - spindle fibres pull chromotids apart to opposite polls of the cell - nuclear membranes reform and cytoplasm divides

Question 29

what is a diploid cell?

Answer 29

a cell with 2 sets of chromosomes

Question 30

what is a haploid?

Answer 30

a cell with 1 sets of chromosome

Question 31

why do organisms need mitosis?

Answer 31

to make new cells for growth and repair

Question 32

what do you need to grow cells in a lab?

Answer 32

- aseptic techniques - broth or agar - control oxygen, temperature and pH

Question 33

describe the structure of DNA

Answer 33

a double stranded helix held together by complementary base pairs

Question 34

list the 4 bases found in DNA

Answer 34

- adenine - thymine - cytosine - guanine

Question 35

what are the pairings of bases in DNA?

Answer 35

adenine + thymine | cytosine + guanine

Question 36

why is the base sequence of DNA important?

Answer 36

so it makes the correct sequence of amino acids to produce protein

Question 37

what does messenger RNA do?

Answer 37

it carries a complementary copy of the code from DNA in the nucleus to a ribosome where proteins are assembled from amino acids

Question 38

why do proteins have different shapes and function?

Answer 38

they have different sequences of amino acids

Question 39

list 5 functions of proteins

Answer 39

``` provide structure enzymes hormones antibodies receptors ```

Question 40

what do enzymes do?

Answer 40

they speed up reactions in a cell and are unchanged in the process

Question 41

which part of the enzyme interacts with the substrate?

Answer 41

active site

Question 42

what is a substrate?

Answer 42

a substance the fits into the active side of an enzyme

Question 43

give an example of an enzyme that takes part in a degradation reaction

Answer 43

pepsin lipase amylase catalase

Question 44

why do enzymes have optimum conditions?

Answer 44

they need conditions which provide the right enzyme shape

Question 45

name 2 conditions that can change protein shape

Answer 45

temperature and pH

Question 46

what is the name given to a protein when its shape is permanently changed by high temperature?

Answer 46

denatured

Question 47

how can DNA be transferred naturally between cells?

Answer 47

bacterial plasmids or viruses

Question 48

list the 4 stages of genetic engineering

Answer 48

- identify and extract required gene - insert gene into plasmid - insert plasmid into host cell - grow modified cell

Question 49

what is respiration?

Answer 49

production of energy from glucose

Question 50

what controls the reactions in respiration?

Answer 50

enzymes

Question 51

what is the energy from sugar used to make?

Answer 51

ATP

Question 52

how is ATP made?

Answer 52

respiration

Question 53

give the equation for 2 different types of anaerobic respiration

Answer 53

glucose = lactic acid + ATP glucose = Carbon dioxide + ethanol + ATP

Question 54

what is ATP used for?

Answer 54

provides energy for cellular activities such as cell contraction, cell division, protein synthesis and nerve impulses

Question 55

what does anaerobic respiration produce?

Answer 55

lactic acid and ATP

Question 56

what does fermentation produce?

Answer 56

alcohol, carbon dioxide and ATP

Question 57

where in a cell does aerobic respiration take place?

Answer 57

begins in the cytoplasm and is completed in the mitochondria

Question 58

where in a cell does fermentation take place?

Answer 58

cytoplasm

Question 59

which types of cell have a high number of mitochondria?

Answer 59

a cell that requires a lot of energy - muscle, sperm, neurons, etc