Save my exams #2

Question 1

dna is producd

Answer 1

semi- conservatiely, with each side being able to be used as a template

Question 2

how dna featues to help replication
(5)

Answer 2

easily broken h bonds between
bases for strands to zip and unzip

double stranded

both strands can be a template

complementary base pairjng allows accurate replication

h bonding is diffrent between a and g and c ans t

Question 3

4 processes required for first cells to form

Answer 3

1- simple organic molecules synthesised from inorganic ones (miller and urey)

2- simple monomers formed polymers (polymerise)

3- polymers got ability to self replicate

4- membrane formed and moleules became isolated from surroundinga

Question 4

polarity is important cause it (3)

Answer 4

is universal solvent cause metabolic actions happen faster in solution and the metabolities can move around easily

can bind to hydrophollic/ polar molecules

allows water molecules to stick together

Question 4

detergent pollutes water cause (3)

Answer 4

reduces surface tension of water

stops water molecules from sticking together

small animals then sink and drown

Question 5

panting helps animals cause

1
2
3
4

Answer 5

1. water vapor is lost from lungs by exhalation
2. water has a high latent heat of vaporisation
3. lots of energy is needed to evaporate water (cause h bonds)
4. resulting in cooling effect

Question 5

why are aqueous solutions clear

Answer 5

each particle (like glucoes) are separated from others

and is surrounded by water particles so isolated/invisible

Question 6

if in doubt conver units to

Answer 6

mm

Question 7

mag (of scale bar)

Answer 7

scale bar lenght (image size)
/ scale bar number (actual size)

Question 8

7000 nm =

Answer 8

7 micro meters, 0.007 mm

Question 9

muscel fibers features

Answer 9

no cell wall
multiple nuclei
a sarcolemma (membrane surrounding muscle fiber)
no specific end
long

Question 10

apart from bases, what can other DNA bases form bonds with (4)

Answer 10

helicase (unwinds double helix and breaks h bonds)

dna polymerase (joins dna nucleotide in dna replication)

rna polymerase (joins rna nucleotide rna transcription)

histone proteins

Question 11

h bonds are weak so constanylu

Answer 11

forming and reforming

tyey can only form bonds with polar molecules

Question 12

polar and bipolar

Answer 12

polar: 1 end + and 1 end -

bipolar: separation of charge

Question 13

phosphlipids

Answer 13

hydrophobic

have hydrocarbon tails which form cell membranes

Question 14

oldest group of h

Answer 14

isptopes found in sea water. in an impact with earth water vapor could have been released

Question 15

dna carries genetic code in

Answer 15

ALL LIVING ORGANISMS ( chlorplast, mitochondria, chromosomes in nucleus)

Question 16

main component of ribosomes

Answer 16

RNA

Question 17

nucleosomes can be tagged

Answer 17

by protein s to surpess transcription

Question 18

how many types of amino acids

Answer 18

20

Question 19

dna has

protein has

Answer 19

phoshorus

sulfur

Question 20

who worked out purine to pyridine structure

Answer 20

chargaff by using paper chromatography

Question 21

sulfur in

phosphorus

Answer 21

supernatant

pellet

Question 22

Multicellular organisms are able to perform functions that unicellular organisms cannot. This is because of their

Answer 22

emergent properties, which occur due to the interaction of different cells, tissues or organs.

Question 23

nucleosomes have

Answer 23

8 histones and LINKER DNA