Biology Paper 1 - 2025 Answers
BIOLOGY PAPER 1 - APEX EXAMINATION COUNCIL 2025
Formatted Answers: Section A and B (Uganda New Curriculum Style)
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SECTION A: Compulsory Questions
1. Bashir's Watermelon Farm
a) Processes affected:
- Transpiration
- Photosynthesis
- Pollination/Fertilization
- Water absorption
- Stomatal regulation
b) How conditions affected plant functioning:
- High temperatures and wind increased transpiration, causing water loss and leaf drooping.
- Closed flowers reduced chances of pollination and fertilization.
- Excessive heat disrupted photosynthesis enzymes, reducing food production.
- Resulted in poor fruit formation and low yield.
c) How watermelons survived:
- Hairy leaves reduced water loss.
Biology Paper 1 - 2025 Answers
- Leaf drooping minimized sun exposure.
- Flowers opened during cooler hours for limited pollination.
- Stomata closed during hot hours to conserve water.
- Stored nutrients supported minimal physiological processes.
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2. Samuel and Drug Abuse
a) Challenges Samuel may face:
- Drug addiction and mental illness
- Poor academic performance
- Criminal behavior and legal issues
- Rejection by peers, teachers, and family
- Long-term health issues and financial struggle
b) Events from eye to brain:
- Light reflected from headteacher enters the eye through cornea and pupil.
- Lens focuses image on retina.
- Retina cells generate impulses sent through optic nerve.
- Brain receives and interprets image.
- Samuel recognizes danger and reacts quickly.
c) Avoiding challenges:
- Cut ties with bad peers.
- Join positive groups like clubs or religious groups.
Biology Paper 1 - 2025 Answers
- Seek counseling or mentorship.
- Focus on education and future goals.
- Report peer pressure to trusted adults.
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3. Nancy's Puberty Experience
a) Expected changes:
- Breast enlargement
- Menstruation begins
- Growth of pubic and armpit hair
- Body shape changes (widened hips)
- Emotional mood swings
- Growth spurts
b) Positive self-image and HIV/AIDS education:
- Accept body changes as normal.
- Focus on talents, hygiene, and inner values.
- Avoid negative peer comparisons.
- Know HIV spreads through unprotected sex, sharing sharp items, or mother to child.
- Practice abstinence and safe behaviors.
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SECTION B: Extended Response
Biology Paper 1 - 2025 Answers
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Part I: Environmental Management
Question 4: Mr. Okello's Land Clearing
a) Environmental challenges caused:
- Deforestation and habitat loss
- Soil erosion and fertility loss
- Destruction of food chains
- Pollution from chemicals
- Loss of biodiversity
- Disruption of soil organisms
b) Why conservation is important:
- Preserves natural habitats and ecosystem services
- Maintains soil fertility and water retention
- Reduces climate change impact
- Supports pollination and sustainable agriculture
- Prevents dependency on expensive inputs
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Question 5: Hill Degradation
Biology Paper 1 - 2025 Answers
a) Causes and solutions:
- Deforestation from charcoal and timber leads to erosion (Solution: Reforestation)
- Bush burning depletes soil fertility (Solution: Mulching and organic farming)
- Cattle grazing compacts soil (Solution: Controlled grazing)
- Slope digging causes mudslides (Solution: Terracing)
b) Why conserve the hill:
- Acts as water catchment area
- Prevents floods and soil loss
- Preserves biodiversity
- Supports agriculture and cultural heritage
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Part II: Health and Human Biology
Question 6: Stephen's Accident and Blood Transfusion
a) Effect on body:
- Blood loss reduced oxygen supply to organs
- Head injury affected consciousness and brain function
- Kidney injury impaired waste removal and water balance
b) Blood donation:
- Stephen is AB (universal recipient)
- All relatives (A, B, AB, O) can donate.
Biology Paper 1 - 2025 Answers
- Best match: Sister with AB group (no antibodies in plasma)
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Question 7: Chandiru's Health Decline
a) Reasons for performance decline:
- HIV weakens immunity
- Respiratory and heart illness reduce energy and oxygen supply
- Malaria causes fatigue and anemia
- Poor appetite leads to nutrient deficiency
- Husband's smoking causes secondhand smoke damage
b) Health management advice:
- Take ARVs consistently
- Sleep under mosquito nets
- Seek treatment for infections
- Avoid smoke exposure
- Maintain balanced diet
- Moderate physical activity and rest
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END OF BIOLOGY PAPER 1 ANSWERS
