1.
State what is meant by a tissue.
[1 mark]
- a group of similar cells with the same function
JD SCIENCE
B2 Scaling up
Indicative marking points. Award marks for equivalent scientific or mathematical wording. Do not issue this sheet with the student worksheet.
2.
State what is meant by an organ system.
[1 mark]
- a group of organs that work together
3.
State what is meant by an enzyme.
[1 mark]
- a biological catalyst / protein that speeds up a reaction
4.
State what is meant by the lock and key theory.
[1 mark]
- the substrate fits the active site exactly
5.
State what is meant by bile.
[1 mark]
- alkaline fluid made in the liver and stored in the gall bladder
6.
State what is meant by the small intestine.
[1 mark]
- organ where most digested food is absorbed
7.
State what is meant by the heart.
[1 mark]
- a muscular pump with four chambers
8.
State what is meant by an artery.
[1 mark]
- a vessel that carries blood away from the heart
9.
State what is meant by a vein.
[1 mark]
- a vessel that carries blood towards the heart
10.
State what is meant by a capillary.
[1 mark]
- a narrow vessel for exchange
11.
Grace is asked about a tissue in a OCR Biology paper.
(a) [2 marks]
- e.g. muscle tissue, xylem
(b) [3 marks]
- why tissues are organised into organs
12.
Grace is asked about an organ system in a OCR Biology paper.
(a) [2 marks]
- e.g. digestive system
(b) [3 marks]
- why the digestive system needs several organs
13.
Grace is asked about an enzyme in a OCR Biology paper.
(a) [2 marks]
- has an active site complementary to the substrate
(b) [3 marks]
- why enzymes are specific
14.
Grace is asked about the lock and key theory in a OCR Biology paper.
(a) [2 marks]
- forms an enzyme-substrate complex
(b) [3 marks]
- why a change in pH reduces rate
15.
Grace is asked about bile in a OCR Biology paper.
(a) [2 marks]
- emulsifies fats and neutralises stomach acid
(b) [3 marks]
- why emulsification increases fat digestion
16.
Grace is asked about the small intestine in a OCR Biology paper.
(a) [2 marks]
- has villi and microvilli
(b) [3 marks]
- why villi increase absorption
17.
A person breathes 12 times a minute, 0.5 dm³ each breath. Calculate the volume breathed in 1 hour.
[3 marks]
- 12 × 0.5 × 60
- Final answer: 360 dm³
18.
Heart rate is 80 bpm and stroke volume is 70 cm³. Calculate cardiac output.
[3 marks]
- CO = HR × SV
- Final answer: 5600 cm³/min
19.
An enzyme reaction produces 24 cm³ of gas in 2 minutes. Calculate the mean rate in cm³/s.
[3 marks]
- 24/120
- Final answer: 0.2 cm³/s
20.
A villus is 1 mm long and there are about 20 per mm². Estimate how many villi on 1 m² of intestine.
[3 marks]
- unit conversions
- Final answer: 2 × 10¹⁰
21.
Blood travels 1.5 m in 1.2 s in an artery. Calculate the mean speed.
[3 marks]
- s = d/t
- Final answer: 1.25 m/s
22.
A patient has a breathing rate of 15 /min. How many breaths in a day?
[3 marks]
- 15×60×24
- Final answer: 21600
23.
Grace carries out the enzyme required practical (amylase and starch / catalase). This is a typical OCR required-practical style question.
(a) [2 marks]
- Independent: pH or temperature
- Dependent: time for starch to disappear / volume of O₂
(b) [2 marks]
- same enzyme volume, same substrate concentration
- so the test is fair / only one variable is changed
(c) [2 marks]
- spotting delays / temperature not constant
24.
Grace carries out food tests for sugar, starch, protein and lipid. This is a typical OCR required-practical style question.
(a) [2 marks]
- Independent: food sample
- Dependent: colour change
(b) [2 marks]
- same volume of reagent
- so the test is fair / only one variable is changed
(c) [2 marks]
- not heating Benedict's for long enough
25.
Grace carries out investigating the effect of pH on amylase. This is a typical OCR required-practical style question.
(a) [2 marks]
- Independent: pH
- Dependent: time to end-point with iodine
(b) [2 marks]
- water bath temperature
- so the test is fair / only one variable is changed
(c) [2 marks]
- not sampling at regular intervals
26.
Grace carries out dissecting a heart or looking at a heart model. This is a typical OCR required-practical style question.
(a) [2 marks]
- Independent: n/a
- Dependent: identification of chambers and vessels
(b) [2 marks]
- follow safety rules
- so the test is fair / only one variable is changed
(c) [2 marks]
- confusing pulmonary artery with aorta
27.
Compare arteries with veins.
[4 marks]
- arteries: high pressure, thick wall
- veins: valves, large lumen
28.
Compare the small intestine with the large intestine.
[4 marks]
- small: digestion and absorption of nutrients
- large: absorption of water
29.
Compare a communicable disease with a non-communicable disease.
[4 marks]
- communicable: caused by a pathogen and can be spread
- non-communicable: e.g. CHD, not spread between people
30.
Compare aerobic exercise effects with long-term training effects on the heart.
[4 marks]
- short term: heart rate rises
- long term: larger stroke volume / lower resting HR
31.
Apply your knowledge of the heart to this situation: blood is pumped to the body at higher pressure
[3 marks]
- blood is pumped to the body at higher pressure
32.
Apply your knowledge of an artery to this situation: withstand high pressure
[3 marks]
- withstand high pressure