GCSE COMBINED SCIENCE HIGHER: BIOLOGY 2018 PAPER 1

Notes:

Question 1. 1  Nucleus = Eurkayotic cell / Permanent Vacuole = Plant cells only /  Plasma = Prokaryotic cell

1.2 tick the bottom box

Vacuole, ribosme, cell wall

1.3  The student should turn the fine focusing knob until the cells are in focus

1.4 Rotate the objective lens to a higher power

1.5 Write the equation -magnification = image size / real size  convert  112mm to 112 000 um

magnification = 112 000/280

answer = 400

 

Question 2.1 a non-communicable disease is not spread from person to person. this is because it is not caused by a pathogen

2.2 CHD can cause a heart attack by restricting blood flow through the artery. This means that less oxygen can reach the heart muscle. This means that the heart cells cannot respire enough.

2.3 Obesity and high cholesterol can cause fatty deposits and CHD. Smoking and high salt diet can cause high blood pressure which increases stress on fatty deposits leading to heart attacks. Genetics can affect how easily you can develop CHD

Question 3.1 6CO2 + 6H2O -----> C6H12O6 + 6O2

3.2 Endothermic

3.3 measure the volume of gas released and measure with an increased length of time

3.4 If the pondweed is at a different temperature then it will have a different rate of photosynthesis this is because temperature affects the rate of photosynthesis and photosynthesis is controlled by enzymes.

3.5  L ∝ 1/5 squared = l ∝1/25     L  ∝ 1/10 squared = L  ∝ 1/100. As the distance doubles, the light intensity is quartered. 

3.6 If you double 20 it would be 40 that would predict  2 bubbles. This is because there is very little light for photosynthesis.

3.7  To vary the carbon dioxide concentration, we would have to use different concentrations of sodium hydrogencarbonate solution.

The other two control variables are the distance from the light source and the temperature for the solution.

Question 4.1 This is because the carrots had different starting masses

4.2 watch a video on that question

4.3  watch a video

4.4 The carrots mass has decreased this is due to loss of water by osmosis. As the concentration of sugar is greater than the concentration of sugar solution inside the carrot. It also requires a partially permeable membrane.

4.5 This is because the high temperature damaged the partially permeable  membrane 

Question5.1 not everyone would go to the doctor 

5.2 percentage change = change / original x 100

1939/2030 x 100 = 95 .5 %

5.4 After the measles exposure, the concentration of antibodies produced was much higher than after the vaccine. Also, the antibodies were created much sooner than after the vaccine where there was a lag.

Antibodies are made by white blood cells. After the vaccine, the white blood cells have remember how to make the specific measles antibodies using memory cells. This means the response can be immediate, large and specific.

Question 6. 1 stem cells are found in the meristem 

6.2  to produce large numbers of identical plants

6.3  6 x 10 to the power of - 12

6.5 Stage 1 - cell grows and replicates the DNA and the other organelles

Stage 2 - The nucleus divides and one set of chromosomes move to each part of the cell.

stage 3 - Cell membrane divides to form two identical cells

My answers: