PAPER 4 BIOLOGY YEAR 11 SEMESTER 1 EXAM

3 1 (a) Fig. 1.1 is a diagram showing the position of some organs in the human body. A B C E D Fig. 1.1 Some of the organs shown in Fig. 1.1 are endocrine glands. Table 1.1 shows the names of some of the endocrine glands, their identifying letters and the hormones that they produce. Complete Table 1.1. Table 1.1 name of endocrine gland letter in Fig. 1.1 hormone produced C insulin testes [3] © UCLES 2021 0610/42/F/M/21 [Turn over

4 (b) Fig. 1.2 shows two graphs representing: • the relative blood concentrations of two hormones, A and B, released by the ovaries during the menstrual cycle • the thickness of the lining of the uterus. relative blood concentration A B of the hormones 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 days thickness of the lining of the uterus 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 days Fig. 1.2 © UCLES 2021 0610/42/F/M/21

5 (i) Describe the roles in the menstrual cycle of hormone A. ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ..................................................................................................................................... [3] (ii) State the day in Fig. 1.2 when ovulation is most likely to occur. ..................................................................................................................................... [1] (iii) State the days in Fig. 1.2 when the lining of the uterus is lost from the body. ..................................................................................................................................... [1] © UCLES 2021 0610/42/F/M/21 [Turn over

6 (c) The female contraceptive pill is a chemical method of birth control, which is available in many countries. (i) Describe the social implications of the increased availability of the female contraceptive pill. ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ..................................................................................................................................... [2] (ii) The hormones in the female contraceptive pill can enter rivers. Describe the negative impacts of female contraceptive hormones entering rivers and contaminating drinking water. ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ..................................................................................................................................... [3] (iii) State two barrier methods of contraception. 1 ........................................................................................................................................ 2 ........................................................................................................................................ [2] [Total: 15] © UCLES 2021 0610/42/F/M/21

8 2 (a) Fig. 2.1 is a diagram of a prokaryotic cell. not to scale Fig. 2.1 (i) State one visible feature in Fig. 2.1 that identifies this cell as a prokaryotic cell. ..................................................................................................................................... [1] (ii) State one cell structure that is present in the cells of all organisms. ..................................................................................................................................... [1] (b) Prokaryotes, Animals and Plants are three of the five kingdoms of organisms. State the names of the two other kingdoms. 1 ................................................................................................................................................ 2 ................................................................................................................................................ [2] (c) Fig. 2.2 shows part of the nitrogen cycle. nitrogen in atmosphere proteins in proteins in animals plants animal waste B C dead organisms A nitrate ions in soil Fig. 2.2 © UCLES 2021 0610/42/F/M/21

9 (i) Describe processes A, B and C in Fig. 2.2. ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ..................................................................................................................................... [6] (ii) State the name of the process that plants use to absorb nitrate ions. ..................................................................................................................................... [1] [Total: 11] © UCLES 2021 0610/42/F/M/21 [Turn over

10 3 (a) The activity of the heart can be monitored using different methods. Fig. 3.1 shows two ECG traces. One trace was recorded when the person was at rest and the second trace was recorded during exercise. The length of time taken for one heart beat is indicated in Fig. 3.1 on the ECG trace recorded at rest. one heart beat at rest 0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 2.2 2.4 2.6 2.8 time / s during exercise 0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 2.2 2.4 2.6 2.8 time / s Fig. 3.1 (i) Estimate the resting heart rate of the person from their ECG trace in Fig. 3.1. Space for working. .................................... beats per minute [2] © UCLES 2021 0610/42/F/M/21

11 (ii) Explain why the ECG trace recorded during exercise differs from the ECG trace recorded at rest. ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ..................................................................................................................................... [4] (iii) Suggest one other way of monitoring the activity of the heart. ........................................................................................................................................... ..................................................................................................................................... [1] (b) If exercise is very intense an oxygen debt is formed. (i) Complete the sentence. An oxygen debt results in a build-up of ................................................ in the ................................................ during vigorous exercise. [2] (ii) Outline how the body removes an oxygen debt. ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ..................................................................................................................................... [4] [Total: 13] © UCLES 2021 0610/42/F/M/21 [Turn over

12 4 (a) A leaf can be described as an organ. Define the term organ. ................................................................................................................................................... ................................................................................................................................................... ............................................................................................................................................. [1] (b) Fig. 4.1 is a photomicrograph of a cross section of part of a leaf. A B C Fig. 4.1 (i) Identify the tissue labelled A in Fig. 4.1. ..................................................................................................................................... [1] (ii) Identify the structure labelled C in Fig. 4.1. ..................................................................................................................................... [1] © UCLES 2021 0610/42/F/M/21

13 (iii) Describe how the tissue labelled B is adapted to maximise photosynthesis. ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ..................................................................................................................................... [3] (c) (i) State two substances that are transported only in the phloem. ..................................................................................................................................... [1] (ii) Explain why some parts of a plant can act as both a source and a sink. ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ........................................................................................................................................... ..................................................................................................................................... [2] © UCLES 2021 0610/42/F/M/21 [Turn over