aqa A-level BIOLOGY Paper 1 (7402/1) JUNE 2023 QUESTION PAPER

aqa A-level BIOLOGY Paper 1 (7402/1) JUNE 2023 QUESTION PAPER. 1. Give the three structural features found in all virus particles and describe the function of one of these features. 2. Explain why viruses are described as acellular and non-living. 3. Give one reason why antibiotics are not effective against viruses. 4. Chitin keeps the tracheae open in the tracheal system of gas exchange in an insect. Gas exchange does not occur in the tracheae. Explain the importance of one adaptation of the gas exchange surface in the tracheal system of an insect. 5. Lignin is a polymer found in the walls of xylem vessels in plants. Lignin keeps the xylem vessel open as a continuous tube. Explain the importance of the xylem being kept open as a continuous tube.