WTM

Question 1

what subcellular structures are in an animal cell

Answer 1

nucleus 
cell membrane 
cytoplasm
mitochondria
ribosomes

Question 2

what subcellular structures are in a plant cell

Answer 2

nucleus
cell membrane 
cell wall
vacuole
mitochondria 
chloroplasts
ribosome's
cytoplasm

Question 3

what is the function of the cell membrane, cell wall and chloroplasts

Answer 3

cell membrane - controls movement of substances in and out of the cell
cell wall - supports the cell
chloroplasts - contain chlorophyll to absorb light for photosynthesis

Question 4

what is the function of the mitochondria, ribosomes and the vacuole

Answer 4

mitochondria - where respiration takes place to release energy
ribosomes - make proteins (protein synthesis)
vacuole - contains cell sap to keep the cell rigid

Question 5

what subcellular structures are in a bacterial cell

Answer 5

plasmid DNA
chromosomal DNA
cell wall
cell membrane 
flagella

Question 6

give three advantages of using an electron microscope to view cells

Answer 6

higher resolution so image is seen clearer
more detail is seen due to a higher magnification
understand more about the cell

Question 7

where in the enzyme does the reaction take place

Answer 7

the active site

Question 8

define the term gene

Answer 8

a section of DNA which codes for a specific protein

Question 9

describe the structure of a DNA molecule

Answer 9

double helix
two strands held together by hydrogen bonds between complementary bases
sugar phosphate backbone

Question 10

what is a mutation

Answer 10

a change in the sequence of bases in DNA

Question 11

define what an isotope is

Answer 11

same number of protons but a different number of neutrons

Question 12

how is an ionic bond formed

Answer 12

gain and loss of electrons
attraction of oppositely charged ions
strong electrostatic force

Question 13

how is a chlorine ion formed from a chlorine atom

Answer 13

chlorine gains 1 electron

Question 14

describe the structure of an ionic compound (lattice)

Answer 14

oppositely charged ions packed together in a regular arrangement

Question 15

give three properties of covalent molecules

Answer 15

low mp
low bp
cannot conduct electricity

Question 16

how do we test for carbon dioxide

Answer 16

turns limewater cloudy

Question 17

calculate the mr of sodium chloride and calcium chloride, show your working .

Answer 17

Na = 23
Cl = 35.5

1x23 = 23

1x35. 5 = 35.5
35. 5 + 23 = 58.5

Question 18

show how to calculate the empirical formula of lithium carbonate if a sample contains 2.8g of lithium, 2.4g of carbon and 9.6g of oxygen

Answer 18

Li = 7       C=12       0= 16
divide 2.8 by 7 = 0.4
divide 2.4 by 12 = 0.2
divide 96 by 16 = 0.6
identify the smallest (0.2)
divide all above answers by the smallest to get 2,1 ,3 so there is 2 lithium, 1 carbon and 3 oxygen

Question 19

what is an alpha particle

Answer 19

2 protons and 2 neutrons

Question 20

how do you calculate work done when given force and distance

Answer 20

E = f x d

Question 21

calculate the equation for KE

Answer 21

KE = 1/2 mv squared

Question 22

how should you put an ammeter into a circuit and what does it measure, give the units

Answer 22

in series
current
amps

Question 23

how should you put a voltmeter into a circuit and what does it measure, give the units

Answer 23

in parallel
voltage / pd
volts

Question 24

explain the effect of increasing resistance on current

Answer 24

reduce current because it more difficult for the electrons to flow

Question 25

state the equation which links charge, current and time

Answer 25

Q = I x t

Question 26

state the three ways of calculating power

Answer 26

P = E/t
P = I x V
P = I squared x R