9700/23

Biology 9700/23May/June 2017

Cambridge AS Level · AS Level Structured Questions · worked solutions for every part, with the mark scheme

6
questions
60
marks
75
minutes

Topics Nucleic Acids and Protein Synthesis · Biological Molecules · Transport in Mammals · Cell Structure · Enzymes · Infectious Diseases · +4 more

Q1Transport in MammalsFree sample

Mammals have a closed double circulation system.

(a)

Explain what is meant by a closed double circulation.

2M
(b)

Table 1.1 shows some structures in the mammalian circulatory system.

Complete Table 1.1 to show the sequence of structures through which blood flows, starting with the pulmonary vein.

Use the numbers 2 to 5 to indicate the correct sequence.

Table 1.1

structuresequence of blood flow
left ventricle
vena cava
pulmonary vein1
aorta
right atrium
2M
(c)
(i)

Explain why arteries have thicker walls than veins.

2M
(ii)

Smoking causes carbon monoxide and nicotine to enter the blood.

Describe the short-term effects of each of these substances on the cardiovascular system.

carbon monoxide

nicotine

4M

The rest of this paper

5 more questions
  • Q2Cell Structure · Nucleic Acids and Protein Synthesis · Enzymes15M
  • Q3Infectious Diseases · Immunity9M
  • Q4Biological Molecules · Nucleic Acids and Protein Synthesis · Cell Membranes and Transport9M
  • Q5Nucleic Acids and Protein Synthesis · The Mitotic Cell Cycle12M
  • Q6Biological Molecules · Transport in Plants5M
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