CIE iGCSE Co-Ordinated Science B12. Respiration Exam Style Questions Paper 3
Question
(a) Fig. 1.1 is a diagram of the male reproductive system in humans.
(i) State the letter from Fig. 1.1 that identifies the part that:
carries urine and semen ………………………………
produces sperm ………………………………
transfers sperm to the urethra. ………………………………
(ii) Draw an X on Fig. 1.1 to identify the position of the prostate gland.
(b) Sperm cells are the male gametes in humans.
Sperm cells are 0.05 mm in length.
Female gametes are 0.1 mm in length.
(i) State the name of the female gametes in humans.
(ii) Calculate how many times longer female gametes are than male gametes.
(c) Sperm cells have a high rate of respiration.
(i) State the word equation for aerobic respiration.
(ii) Complete the sentence about respiration.
Respiration releases the ……………………………… needed for cell division and movement.
(d) Sperm cells are involved in fertilisation.
Describe the process of fertilisation in humans.
Include the site of fertilisation in your answer.
▶️Answer/Explanation
Ans : 1(a)(i) B ;
D ;
A ;
1(a)(ii) X drawn on prostate gland ;
1(b)(i) egg / ova / ovum ;
1(b)(ii) (0.1 / 0.05 =) 2 ;
1(c)(i) glucose + oxygen → carbon dioxide + water
1 mark for reactants ;
1 mark for products ;
1(c)(ii) energy ;
1(d) fusion of the, sperm / male gamete, and, egg / female gamete ;
ref to nuclei ;
fertilisation takes place in the oviduct ;
Question
(a) Fig. 10.1 is a diagram representing the concentration of oxygen molecules outside and inside a cell.
(i) On Fig. 10.1, draw one arrow to represent the net movement of oxygen molecules.
(ii) State the name of the part labelled X in Fig. 10.1.
(iii) Describe one similarity and one difference between diffusion and osmosis.
similarity …………………………………………………………………………
difference …………………………………………………………
(b) Aerobic respiration requires oxygen and releases energy.
(i) State the two products of aerobic respiration.
1 ………………………………………………………………………….
2 …………………………………………………………………………
(ii) Complete these uses of energy in the body of humans.
• ………………………………… contraction
• protein …………………………………
• ………………………………… division
▶️Answer/Explanation
Ans : 10(a)(i) arrow drawn from left to right ;
10(a)(ii) cell membrane ;
10(a)(iii) similarity:
. both involve random movement of particles / movement is down a concentration gradient ;
difference:
. osmosis is the movement of water (only) / osmosis (only) occurs across partially permeable membrane ;
10(b)(i) carbon dioxide ;
water ;
10(b)(ii) muscle ;
synthesis ;
cell ;
Question
(a) A student investigates the germination of pea seeds. (Sub-topic – B3.1)
The student places pea seeds in test-tubes with different conditions and records whether the seeds germinate.
Table 1.1 shows the conditions for each test-tube.
| Test-tube | water present? | oxygen present? |
|---|---|---|
| A | yes | yes |
| B | yes | no |
| C | no | no |
| D | no | yes |
(i) Predict in which test-tube the pea seeds will germinate.
▶️Answer/Explanation
A
Explanation:
Germination requires both water and oxygen. Therefore, the seeds will germinate in test-tube A, where both water and oxygen are present.
(ii) State one other requirement for germination that is not tested in Table 1.1.
▶️Answer/Explanation
suitable temperature
(b) After the seeds germinate, the plant photosynthesizes. (Sub-topic – B6.1)
(i) Complete the sentence to define photosynthesis.
▶️Answer/Explanation
carbohydrates; light
(ii) State the two raw materials needed for photosynthesis.
▶️Answer/Explanation
carbon dioxide; water
(c) Peas contain protein. (Sub-topic – B4.1)
State the name of the smaller molecules from which protein is made.
▶️Answer/Explanation
Proteins are made from smaller molecules called amino acids.
Question
(a) Scientists investigate diffusion by measuring the distance travelled by two different dyes X and Y. They place the dyes on agar plates and measure the distance travelled every 15 seconds. Fig. 4.1 shows the results plotted on a graph. (Sub-topic – B3.1)
(i) Describe the general trend shown by both dyes in Fig. 4.1.
▶️Answer/Explanation
The general trend shown by both dyes is that the distance travelled increases with time. This indicates that diffusion is occurring, and the dyes are spreading out from their original position over time.
(ii) The dyes move through the agar by diffusion. The scientists calculate the average rate of diffusion for dye X after 30 seconds as:
\[ \frac{\text{distance travelled}}{\text{time taken}} = \frac{11}{30} = 0.37 \, \text{mm/s} \]
Calculate the average rate of diffusion for dye Y after 30 seconds.
▶️Answer/Explanation
From the graph, the distance travelled by dye Y after 30 seconds is 6 mm. Therefore, the average rate of diffusion for dye Y is:
\[ \frac{6 \, \text{mm}}{30 \, \text{s}} = 0.2 \, \text{mm/s} \]
(b) Describe the direction of motion of particles during diffusion. (Sub-topic – B3.1)
▶️Answer/Explanation
During diffusion, particles move from a region of higher concentration to a region of lower concentration. This movement occurs due to the random motion of particles, and it continues until the concentration of particles is uniform throughout the medium.
(c) Substances move into and out of cells by diffusion. (Sub-topic – B3.1)
(i) State the part of the cell that controls the movement of substances in and out of the cell.
▶️Answer/Explanation
The cell membrane controls the movement of substances in and out of the cell.
(ii) Circle two substances that diffuse into cells for respiration.
carbon dioxide fatty acids glucose oxygen starch water
▶️Answer/Explanation
The two substances that diffuse into cells for respiration are glucose and oxygen.
(d) Table 4.1 shows some components of plant cells and their function. Complete Table 4.1.
| Component of Plant Cell | Function |
|---|---|
| Vacuole | Contains cell sap to support the plant cell |
| Cytoplasm | Where chemical reactions occur / contains the cell structures / contains enzymes |
| Chloroplast | Where photosynthesis occurs |
▶️Answer/Explanation
The completed table is as follows:
| Component of Plant Cell | Function |
|---|---|
| Vacuole | Contains cell sap to support the plant cell |
| Cytoplasm | Where chemical reactions occur / contains the cell structures / contains enzymes |
| Chloroplast | Where photosynthesis occurs |