biology paper 1

Question 1

high proportion of eosinophills

Answer 1

body produces more cells to combat allergic infection or parasititc infections

Question 2

transport cell

Answer 2

erythrocytes

Question 3

defence cells

Answer 3

leucoytes
platlets

Question 4

how to identify bacteria

Answer 4

-streak plating to seperate from — food faeces
-selective media to isoalte —
-gram staining to identify psotive or nefative
-use antibiodies against –

Question 5

all rna viruses

Answer 5

have a protein coat

Question 6

rna viruses

Answer 6

ebola
hiv
tobbaco mosaic virus

Question 7

conclusion of spearmans rank

Answer 7

if rs > crit value at 5% sig level there is a significant relationship

Question 8

carbon fixing

Answer 8

carbon dioxide diffuses into the stroma
carbon dioxide binds to ribulose biphosphate
using rubisco
resulting in formation of intermediate 6c compound

Question 9

why may a protein be shorter

Answer 9

may produce a stop codon which will stop translation sooner
one or several bases may be deleted therefore mrna shorter

Question 10

epigenetic modifacation

Answer 10

changes that affect gene expression
e.g dna methylation
involved in differentiation

Question 11

antibody producing cell

Answer 11

plasma cell

Question 12

role of krebbs cycle

Answer 12

completely oxidises {pyruvate / acetyl Co A}
 to release as much energy as possible
 to generate ATP (directly)
 to produce {reduced coenzyme / NADH}
 so that ATP can be produced {in the ETC / by oxidative phosphorylation}

Question 13

inner membrane of mitochondria

Answer 13

• role of inner membrane is oxidative phosphorylation
• inner membrane contains proteins involved in electron transport
• inner membrane contains ATPase channels
• movement of protons through ATPase channels results in ATP formation

Question 14

what happens when H+ ions are pumped out of gaurd cells

Answer 14

ATP is broken down into ADP and phosphate ions in hydrolysis

Question 15

types of cells in plant firtilisation and chromasome numebr

Answer 15

female gamete
male gamete
polar body
tube nucleus
all haploid

Question 16

how is tissue fluid formed

Answer 16

(high) hydrostatic pressure forces fluid out of the
capillaries at the arteriole end

Question 17

blood plasma protein count

Answer 17

high
as some proteins are too large to pass out of the blood/capillary

Question 18

why do lipids make more atp then carbs

Answer 18

because a lipid molecule contains a higher proportion of hydrogen
* therefore more reduced NAD / FAD / coenzyme
* therefore more hydrogen (ions) {to accumulate in the intermembrane space for oxidative
phosphorylation

Question 19

movement of water through plant

Answer 19

• water has positively charged hydrogen and a negatively charged oxygen
• therefore hydrogen bonds form between water molecules
• therefore water moved due to cohesion
• because of adhesion / adhesive forces between water and
  xylem

Question 20

structure of chloroplast

Answer 20

formed of protein and mrna
two subunits

Question 21

role of ribsosomes

Answer 21

translation
to hold the tRNA on the mRNA
* whilst peptide bonds form to join amino acids together

Question 22

how do transcription factors increase rate

Answer 22

can switch on gene expression
* bind to a promotor region and stimulate
protein synthesis
* for enzymes involved in glycolysis

Question 23

movement of sucrose through phloem

Answer 23

• by mass flow
• sucrose actively transported into
  phloem in the leaf / at the source
  *sucrose diffuse out of phloem into sink
  tissues
• description of how water enters phloem at source and leaves at sink
• sugars move to region of lower hydrostatic pressure

Question 24

differences in cell mediated response and humorial

Answer 24

antigen presentation in HIR is by B cells
AND
in CMI the infected host cells present the antigen
* {B cells / plasma cells} involved in the HIR but not in the C-MIR
* antibodies involved in HIR
AND
enzymes in C-MIR
* HIR involved in pathogens and infected host
cells and cancer cells
AND
C-MIR involved with host-infected cells

Question 25

where is the etc

Answer 25

inner membrane of mitochondria

Question 26

epigenetic modificatation

Answer 26

changes in gene expression without a change in
base sequence