OVERMUGGED 2024 S3 IP RGS Biology WA2 Revision - Worksheet

REVISION WA2 SEC 3 & SEC 4 KOVAN | BUKIT TIMAH | MARINE PARADE 87702540 OVERMUGGED@GMAIL.COM WWW.OVERMUGGED.COM FOLLOW US ON IG:

© OVERMUGGED | www.overmugged.com | 2024 1 UPPER SECONDARY IP BIOLOGY Cells, Homeostasis, Nervous System, Human Eye RGS S3 WA2 revision Name: Date: Specialised cells Cell Structure Function Red blood cell (Animal cell) Lack nucleus and other organelles Allows red blood cells to pack more haemoglobin per cell to transport oxygen more efficiently around the body Circular, biconcave shape  surface area to volume ratio for rapid diffusion of oxygen into or out of the cell Lack mitochondria To ensure red blood cells do not respire the oxygen they are meant to transport Intestinal epithelial cell (Animal cell) Surface of each epithelial cell covered in small projections called microvilli  surface area to volume ratio for efficient absorption of nutrients Root hair cell (Plant cell) Long and narrow protrusion  surface area to volume ratio for efficient absorption of water and mineral salts No waxy cuticle, concentrated cell sap Provides a steep water potential gradient for greater rate of osmosis Contain numerous mitochondria Provides energy required for active transport of ions into the cell Xylem vessel (Plant cell) Long hollow tubes with no cross walls and protoplasm Continuous and smooth passage of water to transport water and mineral salts Lignin deposit on walls Supports the plant and prevents the vessel from collapsing

© OVERMUGGED | www.overmugged.com | 2024 2 The Nervous System The shortest pathway for nerve impulses to travel from receptor to effector is the reflex arc and explains why reflexes occur so quickly.

© OVERMUGGED | www.overmugged.com | 2024 3 The Human Eye The pupil constricts in bright light to reduce the amount of light entering the eye, protecting the retina from overstimulation. The pupil dilates in dim light to increase the amount of light entering the eye, enhancing dim light vision. The ciliary muscles and suspensory ligaments work together to change the shape of the lens, which increases or decreases the extent to which light rays are refracted. This fine adjustment allows the focal point to land directly on the retina for a clear image to form. A thinner and less convex lens refracts light to a smaller extent while a thicker and more convex lens refracts light to a greater extent.

© OVERMUGGED | www.overmugged.com | 2024 4 Homeostasis – thermoregulation Thermoreceptors in the skin detect changes in skin surface temperature while thermoreceptors in the hypothalamus detect changes in internal body temperature. Being in an extremely warm environment or consuming warm food and drinks will stimulate several corrective mechanisms to bring body temperature down towards the norm. On top of the aforementioned corrective mechanisms, metabolic rate decreases to reduce the rate of heat production. Breathing rate increases to remove more heat via exhaled air.

© OVERMUGGED | www.overmugged.com | 2024 5 Write your answers in the table below. 1 2 3 4 5 6 7 8 9 10 Question 1 [CWSS 2022 S4 Prelim P1 | Q7 - modified] The endomembrane system of a cell performs a variety of functions which are different from the function of the cell surface membrane . The diagram below describes the differences and similarities in structure and function of these membranes. Which row correctly matches the structures to the labelled numbers? (1) (2) (3) (4) (5) (6) (A) Chloroplast Vesicle Smooth ER Rough ER Cell membrane Mitochondrion (B) Cell membrane Rough ER Vesicle Smooth ER Chloroplast Mitochondrion (C) Cell membrane Rough ER Vesicle Smooth ER Mitochondrion Chloroplast (D) Cell membrane Smooth ER Mitochondrion Rough ER Vesicle Chloroplast

© OVERMUGGED | www.overmugged.com | 2024 6 Question 2 [CCHS (Y) 2022 S4 Prelim P1 | Q1 - modified] Radioactively labelled amino acids were introduced into a healthy pancreatic cell. Which structure will the radioactivity first be detected at? (A) Cell membrane (B) Rough endoplasmic reticulum (C) Golgi apparatus (D) Nucleus Question 3 [2022/S4/BBSS/PRELIM/P1/Q28] The finger is accidentally pricked by a pin. The diagram shows part of the nervous system, including a reflex arc, which has been damaged along the line XY. What are the effects of this pin prick? Pain felt Arm moved (A) No No (B) No Yes (C) Yes No (D) Yes Yes

© OVERMUGGED | www.overmugged.com | 2024 7 Question 4 [2022/S4/FCSS/PRELIM/P1/Q22 - modified] The diagram represents a simple reflex arc. In what sequence do nerve impulses pass through during a reflex action? Question 5 [2022/S4/CWSS/PRELIM/P1/Q23] The reaction time of a student is determined by measuring the distance a ruler falls before it is caught by the student. A teacher drops the ruler as shown. Which path is taken by nerve impulses from the student’s eyes to the muscles of his hand? (A) optic nerve → retina → spinal cord → brain → spinal nerve (B) optic nerve → retina → spinal cord → spinal nerve → brain (C) retina → optic nerve → brain → spinal cord → spinal nerve (D) retina → optic nerve → spinal nerve → brain → spinal cord First → Last (A) P Q R (B) Q P R (C) R Q P (D) R P Q

© OVERMUGGED | www.overmugged.com | 2024 8 Question 6 [2022/S4/SCGS/PRELIM/P1/Q25] The diagram shows a front view of the eye with labelled parts X,Y and Z. Which row correctly shows what happens when a person walks from a dark room into a bright room? Question 7 [2022/S4/BSS/PRELIM/P1/Q27] The diagram shows the curvature of the lens in a person’s eye. During which period was a motorbike moving towards the person at a higher speed? Question 8 [SCGS 2022 S4 Prelim P1 | Q18 - modified] Which statement best describes negative feedback? (A) A change away from a set point causes a change back towards the set point. (B) A change away from a set point causes a change to a new set point. (C) A change towards a set point causes a change away from the set point. (D) A change towards a set point is prevented. X Y Z (A) Contract Relax Constrict (B) Relax Constrict Contract (C) Contract Relax Dilate (D) Relax Contract Constrict

© OVERMUGGED | www.overmugged.com | 2024 9 Question 9 [BSS 2022 S4 Prelim P1 | Q23 - modified] The diagram below shows a section through the human skin. During which period of time in the graph below will the muscles in X contract? Question 10 [CVSS 2022 S4 Prelim P1 | Q22 - modified] Organisms native to hot and dry deserts have adaptations that help them survive in those harsh conditions. Which of the following features are appropriate for a desert mouse? Sweat glands Collecting ducts Amount of ADH released (A) More Shorter Less (B) More Longer More (C) Less Shorter Less (D) Less Longer More