AHMES SECONDARY SCHOOL
FORM FIVE ANNUAL HOLIDAY PACKAGE 2025
1. (a) (i) Briefly describe how the mammalian renal tubule is adapted to its functions.
(ii) Explain the mechanism of osmoregulation in marine elasmobranches.
(b) In a comparative study, students observed that the Arctic fox (Vulpes lagopus) has small
ears and a compact body, while the Desert fox (Vulpes zerda) has large ears and a slender
body.
(i) Explain how the body shape and ear size of the Arctic fox are adaptive features in its
environment.
(ii) Predict what might happen to the Arctic fox if it were relocated to a hot desert region.
(iii) Suggest one structural and one behavioral adaptation, other than those already
mentioned, that help Arctic mammals survive in cold conditions.
2. (a) A biology student compared the kidney structure of a desert-dwelling kangaroo rat and a
freshwater beaver. The kangaroo rat was found to have a longer loop of Henle.
(i) Explain how the longer loop of Henle contributes to water conservation in the
kangaroo rat.
(ii) Describe how the counter-current multiplier system helps in creating a concentration
gradient in the medulla.
(iii) Predict the type of urine (concentration and volume) produced by the kangaroo rat
and explain why.
(b) A student stays in a room where the temperature drops to 10°C. Despite the cold, their
internal body temperature remains close to 37°C.
(i) Identify the components involved in this homeostatic response:
– the receptor
– the control centers
– the effectors
(ii) Describe the role of each component in maintaining the student’s body temperature.
(iii) Predict what might happen if the effectors failed to respond properly.
3. (a) A group of students placed celery stalks in coloured water and observed that the colour
moved upwards through the stem.
(i) Identify the vascular tissue responsible for the upward movement of the coloured
water.
(ii) Describe two structural adaptations of this tissue that allow it to efficiently transport
water.
(iii) Predict what would happen to the plant if this tissue was blocked.
(b) A farmer removed a ring of bark from a tree trunk, cutting through the phloem but not
the xylem. Over time, swelling occurred above the cut.
(i) Identify which vascular tissue was disrupted and explain its normal function.
(ii) Explain why swelling occurred above the girdle.
(iii) Predict what would eventually happen to the lower parts of the plant if the affected
vascular tissue remained severed.
4. (a) A student noticed that root hairs absorb mineral ions such as nitrates even when the
concentration of these ions is lower in the soil than inside the root cells.
(i) Identify the type of transport involved in this uptake.
(ii) Explain how this type of transport differs from passive transport.
(iii) Predict what would happen to ion uptake if the root cells were deprived of oxygen.
(b) Describe the process of water uptake from the soil to the xylem.
5. A student studied how water moves from soil into root cells and noticed different pathways
water can take.
(a) Describe the symplasmic, apoplasmic, and vacuolar pathways for water movement across
the root.
(b) Explain how the casparian strip affects these pathways at the endodermis.
(b) Predict what would happen if the casparian strip was damaged or missing.
6. (a) An insect molts several times before reaching adult size.
(i) Describe the type of growth pattern insects exhibit and how it differs from continuous
growth seen in plants.
(ii) Explain the biological reason why molting is necessary for insects.
(iii) Predict how a failure in molting could affect insect growth and survival.
7. A fish grows continuously throughout its life, while a human grows only until adulthood.
(a) Define indeterminate and determinate growth, giving which type applies to the fish
and the human.
(b) Suggest advantages and disadvantages of each growth pattern in animals.
8. Describe the process of mitosis
9. (a) Briefly explain differences between cytokinesis in plant and animal cells.
(b) Differentiate between mitosis in plant and animal cells.
10. (a) Briefly explain why human thymus gland grows at a high rate compared to the rest of the
body parts during infancy.
(b) Differentiate between limited and unlimited growth.
