CSSC FORM FOUR EXAMINATIONS WITH MRKING SCHEMES

CSSC EXAMS

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BIOLOGY WITH MS

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CIVICS WITH MS

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PHYSICS WITH MS

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Form Four National Examinations Summary

Comprehensive overview of Form Four Pre-National Examinations for 2025 conducted by Christian Social Services Commission (CSSC)

Civics Examination

Code: 011 | Date: Wednesday, 13th August 2025 (a.m.) | Duration: 3 Hours

Exam Structure

Sections: A, B, C

Total Questions: 11

Marks Distribution: Section A (16), Section B (54), Section C (30)

Key Topics

Democracy, Governance, Social Problems, Economic Development, Career Development, Culture, Courtship, Globalization, Constitution, Financial Institutions

Question Formats

Multiple Choice, Matching Items, Structured Questions, Essay Questions

Sample Questions

• Describe six voting procedures for general elections
• Explain techniques for solving social problems like crime and poverty
• Analyze the importance of invisible sectors in economic development
• Discuss challenges faced during courtship

Key Answers

Multiple Choice: E, C, D, D, C, B, A, C, A, D

Matching Items: E, C, B, A, H, G

Biology Examination

Code: Biology 1 | Date: Wednesday, 13th August 2025 (p.m.) | Duration: 3 Hours

Exam Structure

Sections: A, B, C

Total Questions: 11

Marks Distribution: Section A (16), Section B (54), Section C (30)

Key Topics

Human Anatomy, Hormones, Genetics, Reproduction, Cell Biology, Evolution, Defense Mechanisms, Excretion, Coordination

Question Formats

Multiple Choice, Matching Items, Structured Questions, Diagram Drawing, Essay Questions

Sample Questions

• Explain how human body provides natural defense against pathogens
• Differentiate between nervous and hormonal coordination
• Describe problems after pancreas removal
• Discuss evidence of organic evolution

Key Answers

Multiple Choice: D, B, E, C, E, D, E, C, C, D

Matching Items: H, B, A, C, H, F

Chemistry Examination

Code: 032/1 | Date: Tuesday, 19th August 2025 (a.m.) | Duration: 3 Hours

Exam Structure

Sections: A, B, C

Total Questions: 11

Marks Distribution: Section A (16), Section B (54), Section C (30)

Key Topics

Chemical Reactions, Atomic Structure, Stoichiometry, Electrochemistry, Acids and Bases, Organic Chemistry, Environmental Chemistry

Question Formats

Multiple Choice, Chemical Equations, Calculations, Structured Questions, Essay Questions

Sample Questions

• Balance chemical equations and identify reaction types
• Perform mole calculations and stoichiometry problems
• Explain industrial processes like Haber and Contact processes
• Discuss environmental impacts of chemical processes

Physics Examination

Code: 031 | Date: Monday, 25th August 2025 (a.m.) | Duration: 2.5 Hours

Exam Structure

Sections: A, B, C

Total Questions: 10

Marks Distribution: Section A (15), Section B (70), Section C (30)

Key Topics

Mechanics, Electricity, Magnetism, Light, Waves, Energy, Thermodynamics

Question Formats

Multiple Choice, Calculations, Diagram Drawing, Structured Questions, Essay Questions

Sample Questions

• Solve problems on motion and forces
• Apply Ohm's law in electrical circuits
• Explain magnetic fields and electromagnetic induction
• Analyze optical systems and wave phenomena

Mathematics Examination

Code: 041 | Date: Wednesday, 20th August 2025 (a.m.) | Duration: 2.5 Hours

Exam Structure

Sections: A, B

Total Questions: 10

Marks Distribution: All questions carry 10 marks each

Key Topics

Algebra, Geometry, Trigonometry, Statistics, Calculus, Coordinate Geometry, Sets, Matrices

Question Formats

Calculations, Proofs, Problem Solving, Graphical Representations

Sample Questions

• Solve simultaneous equations
• Calculate areas and volumes of geometric shapes
• Apply trigonometric functions to solve problems
• Analyze statistical data and probability

© 2023 Form Four National Examinations Summary | Christian Social Services Commission (CSSC)

Northern Zone Joint Examinations Syndicate (NZ-JES) | 2025 Pre-National Examinations

CSSC FORM TWO EXAMINATION (With Marking Schemes)

Form Two Examination Summary

Christian Social Services Commission (CSSC) - Northern Zone Joint Examinations Syndicate (NZ-JES)

Overview

The Form Two Pre-National Assessment for 2025 was conducted by the Christian Social Services Commission (CSSC) through the Northern Zone Joint Examinations Syndicate (NZ-JES). The assessment covered three core subjects: Physics, Chemistry, and Basic Mathematics, each designed to evaluate students' understanding of fundamental concepts and their application abilities.

The examinations were structured to test knowledge across various cognitive levels, from basic recall to application and problem-solving. Each paper included multiple-choice questions, structured questions, and in some cases, practical or diagram-based questions to comprehensively assess student competency.

Physics Examination

The Physics paper (Code 031) was a 2.5-hour examination consisting of three sections with a total of ten questions. Section A included multiple-choice questions covering laboratory safety, light properties, electricity, mechanics, and energy concepts. Section B required detailed answers on topics including magnetism, thermodynamics, motion, and simple machines.

Key areas assessed included:

• Laboratory safety precautions and procedures
• Light behavior through different materials
• Electrical calculations using Ohm's Law
• Pressure and surface area relationships
• Image formation in mirrors
• Energy transformations
• Density calculations
• Static electricity concepts
• Renewable and non-renewable energy sources

Section C included more advanced problems involving velocity-time graphs, momentum conservation, and machine efficiency calculations.

Chemistry Examination

The Chemistry paper (Code 032/1) was a 3-hour examination divided into three sections. Section A contained multiple-choice questions testing fundamental concepts including types of mixtures, gas identification, combustion, chemical bonding, and scientific methodology.

Notable content areas included:

• Types of chemical reactions and equations
• Atomic structure and subatomic particles
• Stoichiometry and mole concept calculations
• Electrochemistry and Faraday's laws
• Catalysis in industrial processes
• Chemical bonding and compound formation
• Isomerism in organic compounds
• Environmental chemistry and pollution
• Metal extraction processes

The examination required students to balance chemical equations, perform calculations involving moles and gas volumes, and explain chemical processes in industrial and environmental contexts.

Basic Mathematics Examination

The Basic Mathematics paper (Code 041) was a 2.5-hour examination consisting of ten compulsory questions covering a wide range of mathematical concepts and skills.

Key content areas included:

• Number operations including GCF, LCM, and decimal conversions
• Unit conversions and significant figures
• Geometry including angle calculations and area problems
• Algebra including simultaneous equations and quadratic equations
• Ratio, proportion, and percentage calculations
• Coordinate geometry and transformations
• Logarithms and surds
• Trigonometry and exact values
• Set theory and Venn diagrams
• Statistics including frequency distributions

The paper emphasized practical application of mathematical concepts to real-world situations, requiring students to show all working and provide answers in simplest form where appropriate.

Examination Structure

All examinations followed a similar pattern with clear instructions regarding allowed materials (non-programmable calculators only), prohibited items (communication devices), and requirements for writing assessment numbers on every page. Each paper provided necessary constants and formulas, reducing the need for memorization and focusing instead on application of concepts.

The assessments were designed to prepare students for national-level examinations while identifying areas needing improvement in the Form Two curriculum. The balanced approach between theoretical knowledge and practical application aimed to develop well-rounded students capable of critical thinking and problem-solving across scientific and mathematical disciplines.

CSSC FORM TWO EXAMINATIONS

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KISWAHILI

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BASIC MATHEMATICS

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Form Two National Exam Topics

Comprehensive list of topics commonly tested in Form Two National Examinations

Mathematics

10+ Key Topics

• Algebra and Equations
• Geometry and Angles
• Statistics and Data Handling
• Fractions, Decimals, and Percentages
• Ratios and Proportions
• Coordinate Geometry
• Sets and Venn Diagrams
• Commercial Arithmetic
• Linear Programming
• Trigonometry

Physics

8+ Key Topics

• Measurements and Units
• Force and Motion
• Work, Energy, and Power
• Simple Machines
• Pressure in Solids and Liquids
• Temperature and Heat
• Light and Optics
• Static Electricity
• Current Electricity
• Magnetism

Chemistry

9+ Key Topics

• Introduction to Chemistry
• States of Matter
• Elements, Compounds, and Mixtures
• Air Combustion and Rusting
• Atomic Structure
• Periodic Classification
• Water and Hydrogen
• Chemical Reactions
• Acids, Bases, and Salts
• Carbon and Its Compounds

Biology

8+ Key Topics

• Classification of Living Things
• Cell Structure and Organization
• Nutrition in Plants and Animals
• Transport in Living Things
• Gaseous Exchange and Respiration
• Excretion and Homeostasis
• Coordination and Response
• Reproduction in Plants and Animals
• Genetics
• Ecology

English Language

7+ Key Topics

• Comprehension and Summary
• Grammar and Usage
• Composition Writing
• Poetry Analysis
• Novel and Play Analysis
• Vocabulary Development
• Oral Literature
• Essay Writing Techniques
• Language Skills

Civics

6+ Key Topics

• The Concept of Citizenship
• Human Rights
• Responsible Decision Making
• Government of Tanzania
• Democracy
• Law and Society
• Economic Development
• Global Issues

History

7+ Key Topics

• Evolution of Man
• Development of Economic Activities
• Contacts between East Africa and the Outside World
• Social Economic and Political Development
• African and Tanzania Independence
• International Relations
• Development of Social Services

Geography

8+ Key Topics

• The Solar System
• Major Features of the Earth's Surface
• Weather and Climate
• Map Reading and Interpretation
• Sustainable Use of Power and Energy Resources
• Human Activities
• Environmental Issues and Conservation
• Transport and Communication

© 2023 Form Two National Exam Topics | Comprehensive guide to examination preparation

Note: Topics may vary slightly by education system and country

MITIHANI POPOTE EXAMINATIONS SERIES FORM FOUR CHEMISTRY EXAMINATION SERIES 10 (With Marking Guide)

FORM FOUR CHEMISTRY EXAMINATION SERIES 10

Chemistry Examination Answers
Series 10

Section A (15 Marks)

Question 1(i)

Splints are among the first aid kit components. Which of the following sentences best describes its use?

C. Used to support broken bones and is tied using bandages

Splints serve crucial medical purposes:

• Immobilization: Prevent movement of fractured bones to avoid further injury
• Pain reduction: Minimize pain by stabilizing the injury
• Healing: Maintain proper bone alignment during healing
• Types: Can be rigid (wood/metal) or flexible (inflatable)

First aid splints are temporary until professional medical care is available.

Question 1(ii)

A simple proof that some chemical reactions take place in our bodies is that

D. The food we eat or the drinks we take are quite different from the waste products from our bodies

This demonstrates metabolic transformations:

• Digestion: Complex carbohydrates → simple sugars
• Respiration: Glucose + O₂ → CO₂ + H₂O + energy
• Protein metabolism: Amino acids → urea
• Evidence: Chemical analysis shows food (input) and excretory products (output) have completely different compositions

Question 1(iii)

The reaction, 4NH₃(g) + 5O₂(g) → 4NO(g) + 6H₂O(g), is an example of a

C. Redox reaction

This is the Ostwald process for nitric acid production:

• Oxidation: N changes from -3 (NH₃) to +2 (NO)
• Reduction: O changes from 0 (O₂) to -2 (H₂O)
• Simultaneous: Both oxidation and reduction occur
• Industrial importance: First step in nitric acid manufacture

NH₃ oxidation: -3 → +2 (loss of 5e⁻ per N atom)

O₂ reduction: 0 → -2 (gain of 2e⁻ per O atom)

Question 2 - Matching

List A	List B	Explanation
(i) Lime water turns milky when air is pumped	E. Presence of carbon dioxide	CO₂ reacts with Ca(OH)₂ to form insoluble CaCO₃
(ii) Condition for iron to rust	B. Oxygen and water/moisture	Both required for electrochemical corrosion
(iii) Oxygen, Heat and Fuel	D. Fire triangle	Three components needed for combustion
(iv) Coating iron with zinc	G. Galvanization	Zinc sacrificially protects iron from rusting
(v) Flammable liquids	H. Class B fire	Classification for liquid fuel fires

Section B (70 Marks)

Question 3 7 marks

(a) Water hardness analysis:

(i) Harder water brand: Uhai

Hardness is primarily caused by Ca²⁺ and Mg²⁺ ions:

• Uhai: 3.05 mg/L Ca²⁺ + 4.15 mg/L Mg²⁺ = 7.2 mg/L total hardness
• Dasani: 2.69 mg/L Ca²⁺ + 0.11 mg/L Mg²⁺ = 2.8 mg/L total hardness
• Higher mineral content = greater hardness

(ii) Calcium benefits:

1. Essential for bone and teeth development
2. Required for muscle function and nerve transmission
3. Helps blood clotting

(iii) Water treatment: Chlorine is added as disinfectant

(b) Hydrogen vs. Phosphorus:

(i) More electropositive: Hydrogen

Electropositivity decreases across periods:

• Hydrogen (Group 1) more likely to lose electrons
• Phosphorus (Group 15) more electronegative

(ii) Compound formed: PH₃ (Phosphine)

P + 3H → PH₃

Question 4 7 marks

Oxygen preparation:

2H₂O₂(l) → 2H₂O(l) + O₂(g)

(a)(i) MnO₂ role: Catalyst

Manganese dioxide:

• Provides alternative reaction pathway
• Lowers activation energy
• Not consumed in reaction

(ii) Without catalyst: Reaction would be extremely slow

(b) Oxygen test:

1. Insert glowing splint into gas
2. Positive test: splint reignites brightly
3. Confirms presence of oxygen (supports combustion)

Question 7 7 marks

Molecular formula determination:

Given: 86% C, 14% H; 3.2 dm³ = 6g at STP

Step 1: Empirical formula

Element	%	Moles	Ratio
C	86	86/12 = 7.17	7.17/7.14 ≈ 1
H	14	14/1 = 14	14/7.14 ≈ 2

Empirical formula: CH₂ (Mass = 14 g/mol)

Step 2: Molar mass

3.2 dm³ = 0.143 mol (3.2/22.4)

Molar mass = 6g/0.143mol = 42 g/mol

Step 3: Molecular formula

n = 42/14 = 3 → (CH₂)₃ = C₃H₆

Molecular formula: C₃H₆

Section C (15 Marks)

Question 13 15 marks

Water pollution prevention methods:

1. Proper waste disposal:
   • Treat industrial effluents before discharge
   • Implement sewage treatment systems
2. Agricultural management:
   • Controlled fertilizer/pesticide use
   • Establish buffer zones near water bodies
3. Oil spill prevention:
   • Proper maintenance of oil tankers
   • Quick response protocols
4. Public education:
   • Promote proper chemical disposal
   • Encourage water conservation
5. Legislation:
   • Enforce water quality standards
   • Penalize polluters
6. Ecosystem protection:
   • Preserve wetlands (natural filters)
   • Maintain riparian vegetation

Probability Questions (With detailed answers)

Probability Questions

1.

An individual is picked at random from a group of 52 athletes. Suppose that 26 of the athletes are female of which 6 are swimmers. Also, there are 10 swimmers among male athletes.

(a) Given that the individual picked is a female, find the probability that she is a swimmer.

(b) Given that the individual picked is a swimmer, find the probability that he is a male.

2.

A basket contains 10 apples and 20 oranges out of which 3 apples and 5 oranges are defective. If we choose two fruits at random, what is the probability that either both are oranges or both are non-defective?

3.

A packing plant fills bags with cement. The weight X kg of a bag of cement can be modelled by a normal distribution with mean 50kg and standard deviation 2kg.

i. Find P(X > 53)

ii. Find the weight that is exceeded by 99% of the bags

iii. Three bags are selected at random, find the probability that two weigh more than 53kg and one weighs less than 53kg.

4.

From experience a high-jumper knows that he can clear a height of at least 1.78m once in 5 attempts. He also knows that he can clear a height of at least 1.65m on 7 out of 10 attempts. Assuming that heights the high-jumper can reach follow a Normal Distribution,

(a) Draw a sketch to illustrate the above information

(b) Find to three decimal places, the mean and standard deviation of the heights the high-jumper can reach.

(c) Calculate the probability that he can jump at least 1.74m.

5.

A drinks machine dispenses coffee into cups. A sign on the machine indicates that each cup contains 50ml of coffee. The machine actually dispenses a mean amount of 55ml per cup and 10% of the cups contain less than the amount stated on the sign. Assuming that the amount of coffee dispensed into each cup is normally distributed, find;

(a) The standard deviation of the amount of coffee dispensed per cup in ml,

(b) The percentage of cups that contains more than 61ml

(c) Following complaints, the owners of the machine make adjustments. Only 2.5% of cups now contain less than 50ml. The standard deviation of the amount dispensed is reduced to 3ml. Assuming that the amount of coffee dispensed is still normally distributed, find the new mean amount of coffee per cup.

Probability Questions with Detailed Solutions

Question 1

An individual is picked at random from a group of 52 athletes. Suppose that 26 of the athletes are female of which 6 are swimmers. Also, there are 10 swimmers among male athletes.

(a) Given that the individual picked is a female, find the probability that she is a swimmer.

Solution:

We use conditional probability:

P(Swimmer | Female) = Number of female swimmers / Total number of females

Given:

• Total females = 26
• Female swimmers = 6

P(Swimmer | Female) = 6/26 = 3/13 ≈ 0.2308 or 23.08%

(b) Given that the individual picked is a swimmer, find the probability that he is a male.

Solution:

First, find total number of swimmers:

Female swimmers = 6
Male swimmers = 10
Total swimmers = 6 + 10 = 16

Now use conditional probability:

P(Male | Swimmer) = Number of male swimmers / Total number of swimmers

P(Male | Swimmer) = 10/16 = 5/8 = 0.625 or 62.5%

Question 2

A basket contains 10 apples and 20 oranges out of which 3 apples and 5 oranges are defective. If we choose two fruits at random, what is the probability that either both are oranges or both are non-defective?

Solution:

Total fruits = 10 apples + 20 oranges = 30

Case 1: Both are oranges

Number of ways to choose 2 oranges from 20:

C(20, 2) = 20!/(2! × 18!) = 190

Case 2: Both are non-defective

Non-defective apples = 10 - 3 = 7
Non-defective oranges = 20 - 5 = 15
Total non-defective = 7 + 15 = 22

Number of ways to choose 2 non-defective fruits:

C(22, 2) = 22!/(2! × 20!) = 231

Overlap: Both are oranges AND non-defective

Number of ways to choose 2 non-defective oranges:

C(15, 2) = 15!/(2! × 13!) = 105

Using the inclusion-exclusion principle:

P(A ∪ B) = P(A) + P(B) - P(A ∩ B)

= C(20,2)/C(30,2) + C(22,2)/C(30,2) - C(15,2)/C(30,2)

= (190 + 231 - 105)/435 = 316/435 ≈ 0.7264 or 72.64%

Question 3

A packing plant fills bags with cement. The weight X kg of a bag of cement can be modelled by a normal distribution with mean 50kg and standard deviation 2kg.

i. Find P(X > 53)

Solution:

First, calculate the z-score:

z = (x - μ)/σ = (53 - 50)/2 = 1.5

Using standard normal distribution tables:

P(X > 53) = P(Z > 1.5) = 1 - P(Z ≤ 1.5) = 1 - 0.9332 = 0.0668 or 6.68%

ii. Find the weight that is exceeded by 99% of the bags

Solution:

We need to find x such that P(X > x) = 0.99, which means P(X ≤ x) = 0.01

Find z-score corresponding to cumulative probability 0.01:

z ≈ -2.326 (from standard normal tables)

Convert back to original scale:

x = μ + zσ = 50 + (-2.326)(2) ≈ 50 - 4.652 ≈ 45.348 kg

Therefore, 99% of bags exceed approximately 45.35 kg.

iii. Three bags are selected at random, find the probability that two weigh more than 53kg and one weighs less than 53kg.

Solution:

From part (i), P(X > 53) = 0.0668
Therefore, P(X ≤ 53) = 1 - 0.0668 = 0.9332

This is a binomial probability problem with n=3, k=2, p=0.0668

P(2 >53 and 1 ≤53) = C(3,2) × (0.0668)² × (0.9332)¹

= 3 × 0.004462 × 0.9332 ≈ 0.0125 or 1.25%

Question 4

From experience a high-jumper knows that he can clear a height of at least 1.78m once in 5 attempts. He also knows that he can clear a height of at least 1.65m on 7 out of 10 attempts. Assuming that heights the high-jumper can reach follow a Normal Distribution,

(a) Draw a sketch to illustrate the above information

Solution:

[Visual sketch would show:]

• A normal distribution curve with mean μ and standard deviation σ
• 1.78m marked on the right tail with area to the right = 1/5 = 0.2
• 1.65m marked further left with area to the right = 7/10 = 0.7

(b) Find to three decimal places, the mean and standard deviation of the heights the high-jumper can reach.

Solution:

We have two equations:

1. P(X > 1.78) = 0.2 ⇒ P(X ≤ 1.78) = 0.8
Corresponding z-score ≈ 0.842

2. P(X > 1.65) = 0.7 ⇒ P(X ≤ 1.65) = 0.3
Corresponding z-score ≈ -0.524

Set up equations:
(1.78 - μ)/σ = 0.842
(1.65 - μ)/σ = -0.524

Solving these simultaneously:
From first equation: μ = 1.78 - 0.842σ
Substitute into second equation:
(1.65 - (1.78 - 0.842σ))/σ = -0.524
(-0.13 + 0.842σ)/σ = -0.524
-0.13/σ + 0.842 = -0.524
-0.13/σ = -1.366
σ ≈ 0.0952

Then μ ≈ 1.78 - 0.842(0.0952) ≈ 1.78 - 0.080 ≈ 1.700

Final answers:
Mean (μ) ≈ 1.700 m
Standard deviation (σ) ≈ 0.095 m

(c) Calculate the probability that he can jump at least 1.74m.

Solution:

Using μ = 1.700, σ = 0.095:

z = (1.74 - 1.700)/0.095 ≈ 0.421

P(X > 1.74) = P(Z > 0.421) = 1 - P(Z ≤ 0.421) ≈ 1 - 0.6635 ≈ 0.3365 or 33.65%

Question 5

A drinks machine dispenses coffee into cups. A sign on the machine indicates that each cup contains 50ml of coffee. The machine actually dispenses a mean amount of 55ml per cup and 10% of the cups contain less than the amount stated on the sign. Assuming that the amount of coffee dispensed into each cup is normally distributed, find;

(a) The standard deviation of the amount of coffee dispensed per cup in ml,

Solution:

Given:

• μ = 55 ml
• P(X < 50) = 0.10

Find z-score corresponding to P(Z < z) = 0.10:
z ≈ -1.2816

z = (x - μ)/σ
-1.2816 = (50 - 55)/σ
σ = -5/-1.2816 ≈ 3.901 ml

(b) The percentage of cups that contains more than 61ml

Solution:

Using μ = 55 ml, σ ≈ 3.901 ml:

z = (61 - 55)/3.901 ≈ 1.538

P(X > 61) = P(Z > 1.538) = 1 - P(Z ≤ 1.538) ≈ 1 - 0.938 ≈ 0.062 or 6.2%

(c) Following complaints, the owners of the machine make adjustments. Only 2.5% of cups now contain less than 50ml. The standard deviation of the amount dispensed is reduced to 3ml. Assuming that the amount of coffee dispensed is still normally distributed, find the new mean amount of coffee per cup.

Solution:

Given:

• New σ = 3 ml
• P(X < 50) = 0.025

Find z-score corresponding to P(Z < z) = 0.025:
z ≈ -1.96

z = (x - μ)/σ
-1.96 = (50 - μ)/3
μ = 50 + 1.96 × 3 = 50 + 5.88 = 55.88 ml

The new mean is approximately 55.88 ml.

FORM FOUR BIOLOGY EXAMINATION - TOPIC: HIV/AIDS (With Marking Scheme)

FORM FOUR BIOLOGY EXAMINATION

TOPIC: HIV/AIDS

Time: 3 Hours

Instructions

• Answer all questions in Sections A and B.
• Answer any two (2) questions from Section C.
• Neat diagrams must be used wherever applicable.

SECTION A (16 Marks)

1. Multiple Choice Questions (10 marks)

Choose the correct answer for each item:

(i) HIV mainly attacks which type of cells in the human body?
a) Red blood cells
b) Platelets
c) White blood cells
d) Skin cells

(ii) Which method is most reliable for determining HIV status?
a) Physical examination
b) Observation of symptoms
c) Blood testing at VCT
d) Asking a sexual partner

(iii) The virus that causes AIDS is classified under:
a) Bacteria
b) Fungi
c) Protozoa
d) Virus

(iv) A common opportunistic infection in AIDS patients is:
a) Cholera
b) Malaria
c) Tuberculosis
d) Typhoid

(v) The window period in HIV infection refers to:
a) Time before birth
b) Time after infection but before symptoms
c) Time when HIV can be cured
d) Time when the virus mutates

(vi) The abbreviation VCT stands for:
a) Virus Control Therapy
b) Voluntary Counseling and Testing
c) Viral Cure Treatment
d) Vaccination Control Test

(vii) HIV can be transmitted through:
a) Sharing utensils
b) Sneezing
c) Unprotected sex
d) Mosquito bites

(viii) Responsible sexual behavior includes:
a) Early marriage
b) Abstinence
c) Peer pressure
d) Frequent testing only

(ix) Which body fluid does NOT transmit HIV?
a) Blood
b) Breast milk
c) Sweat
d) Semen

(x) An individual living positively with HIV means:
a) They spread HIV knowingly
b) They deny their status
c) They maintain health and follow treatment
d) They avoid all people

2. Matching Items (6 Marks)

Match the items in List A with responses from List B:

List A

(i) Breastfeeding by HIV positive mother

(ii) Proper condom use

(iii) VCT services

(iv) Sharing needles

(v) Abstinence

(vi) ARV drugs

List B

a) Prevents new HIV infections

b) Increases risk of HIV transmission

c) Used to control HIV progression

d) A way to know HIV status

e) Sexual self-control

f) Risky traditional practice

Answers:

1. Breastfeeding by HIV positive mother - b) Increases risk of HIV transmission
2. Proper condom use - a) Prevents new HIV infections
3. VCT services - d) A way to know HIV status
4. Sharing needles - f) Risky traditional practice
5. Abstinence - e) Sexual self-control
6. ARV drugs - c) Used to control HIV progression

SECTION B (54 Marks)

3.

Mama Asha, a community health worker, is educating youth about HIV.

a) Explain the importance of VCT in preventing the spread of HIV. (5 marks)

Answer:

1. Identifies HIV-positive individuals who can then take precautions to prevent transmission
2. Provides opportunity for counseling about prevention methods
3. Encourages behavior change through awareness of status
4. Early detection allows for early treatment which reduces viral load and infectiousness
5. Helps prevent mother-to-child transmission through early detection

b) Describe any two methods used in VCT to detect HIV infection. (4 marks)

Answer:

1. Rapid HIV tests: Provide results in 20-30 minutes using blood from finger prick or oral fluid
2. ELISA test: Highly sensitive laboratory test that detects HIV antibodies in blood
3. Western Blot test: Used to confirm positive ELISA results, more specific but expensive
4. PCR test: Detects viral RNA, useful during window period before antibodies develop

4.

Hamisi believes hugging or eating with an infected person can spread HIV.

a) Identify and correct Hamisi's misconceptions. (4 marks)

Answer:

1. Misconception: HIV spreads through casual contact like hugging
   Correction: HIV cannot be transmitted through skin-to-skin contact like hugging
2. Misconception: Eating with infected person spreads HIV
   Correction: HIV is not transmitted through saliva or sharing utensils

b) Outline four main modes of HIV transmission. (5 marks)

Answer:

1. Unprotected sexual intercourse (vaginal, anal, oral)
2. Mother-to-child transmission (during pregnancy, delivery, or breastfeeding)
3. Contact with infected blood (transfusions, needle sharing, occupational exposure)
4. Use of unsterilized sharp objects (tattooing, circumcision, piercing instruments)

5.

At a youth seminar, students were taught about responsible sexual behavior.

a) State three examples of responsible sexual behavior. (3 marks)

Answer:

1. Abstinence (delaying sexual debut)
2. Mutual faithfulness to one uninfected partner
3. Consistent and correct condom use

b) Explain the importance of each example in preventing HIV. (6 marks)

Answer:

1. Abstinence: Completely eliminates risk of sexual HIV transmission, especially important for youth
2. Mutual faithfulness: Reduces exposure to multiple partners and potential HIV infection
3. Condom use: Creates physical barrier preventing exchange of infected body fluids

6.

A nurse is training people on the role of ARVs.

a) What are ARVs and how do they work? (4 marks)

Answer:

ARVs (Antiretroviral drugs) are medications used to treat HIV infection. They work by:

1. Inhibiting viral replication at different stages of the HIV life cycle
2. Reducing viral load in the body
3. Preserving immune function by protecting CD4 cells
4. Preventing progression to AIDS

b) Why is it important to adhere to ARV medication schedules? (5 marks)

Answer:

1. Maintains consistent drug levels in blood to suppress viral replication
2. Prevents development of drug-resistant HIV strains
3. Ensures maximum effectiveness of treatment
4. Maintains low viral load which preserves immune function
5. Reduces risk of transmitting HIV to others

7.

A young couple plans to marry and visits a health clinic.

a) Explain the purpose of pre-marital HIV testing. (4 marks)

Answer:

1. Allows couples to make informed decisions about their relationship
2. Enables early treatment if either partner is HIV-positive
3. Helps prevent transmission between partners
4. Provides opportunity to discuss prevention of mother-to-child transmission
5. Reduces stigma by normalizing HIV testing

b) List five benefits of knowing your HIV status. (5 marks)

Answer:

1. Early access to treatment if positive
2. Ability to take precautions to prevent transmission
3. Peace of mind if negative
4. Better family planning decisions
5. Reduced anxiety through knowledge of status
6. Opportunity to adopt healthier lifestyle choices

8.

A family is caring for an HIV positive child.

a) Describe three ways the family can support the child's health. (6 marks)

Answer:

1. Medical care: Ensure regular clinic visits and adherence to ARV medication
2. Nutrition: Provide balanced diet to boost immune system
3. Hygiene: Maintain clean environment to prevent infections
4. Education: Help child understand and manage their condition appropriately
5. Social support: Encourage normal childhood activities and schooling

b) Why is emotional support important in HIV management? (3 marks)

Answer:

1. Reduces stress which can weaken immune system
2. Improves medication adherence
3. Helps prevent depression and mental health issues
4. Promotes better quality of life

SECTION C (30 Marks)

Answer any two (2) questions from this section.

9.

Discuss the social and economic impacts of HIV/AIDS at the family and national level. (15 marks)

Answer:

Family Level Impacts:

1. Economic:
   • Loss of income due to illness/death of breadwinners
   • Increased medical expenses
   • Reduced productivity of family members
2. Social:
   • Orphaned children and strained family structures
   • Stigma and discrimination against affected families
   • Disruption of children's education to care for sick relatives

National Level Impacts:

1. Economic:
   • Reduced workforce productivity
   • Increased healthcare costs
   • Reduced GDP growth
   • Increased dependency ratio
2. Social:
   • Overburdened healthcare systems
   • Increased number of orphans and vulnerable children
   • Reduced life expectancy
   • Strain on social services

10.

Describe the life cycle of the HIV virus and explain how this contributes to the difficulty in curing HIV. (15 marks)

Answer:

HIV Life Cycle:

1. Attachment: HIV binds to CD4 receptors on host cells
2. Fusion: Viral envelope fuses with cell membrane
3. Reverse transcription: Viral RNA converted to DNA by reverse transcriptase
4. Integration: Viral DNA incorporated into host genome
5. Replication: Host cell produces viral components
6. Assembly: New virus particles assembled
7. Budding: New viruses released from host cell

Challenges for Cure:

1. Integration into host DNA: Makes complete viral eradication difficult
2. High mutation rate: Leads to drug resistance
3. Latent reservoirs: Virus hides in dormant cells
4. Immune system evasion: Virus attacks immune cells
5. Genetic diversity: Multiple HIV subtypes exist

11.

Explain five major strategies that can be used in Tanzania to reduce the spread of HIV/AIDS. Support your answer with relevant examples. (15 marks)

Answer:

1. Comprehensive sex education:
   • School-based programs teaching abstinence and safe sex
   • Example: Peer education programs in secondary schools
2. Promotion of VCT services:
   • Mobile testing units to reach rural areas
   • Example: National HIV testing campaigns
3. Prevention of mother-to-child transmission (PMTCT):
   • ARVs for pregnant women and safe delivery practices
   • Example: PMTCT programs in antenatal clinics
4. Harm reduction for high-risk groups:
   • Needle exchange programs for drug users
   • Example: Programs in Dar es Salaam for intravenous drug users
5. Stigma reduction campaigns:
   • Public awareness to encourage testing and treatment
   • Example: Media campaigns featuring HIV+ individuals
6. Condom promotion and distribution:
   • Free condoms in health facilities and public places
   • Example: Government condom distribution program

FORM FOUR BIOLOGY EXAMINATION ANSWERS

TOPIC: HIV/AIDS

SECTION A ANSWERS (16 Marks)

1. Multiple Choice Answers

1. c) White blood cells
2. c) Blood testing at VCT
3. d) Virus
4. c) Tuberculosis
5. b) Time after infection but before symptoms
6. b) Voluntary Counseling and Testing
7. c) Unprotected sex
8. b) Abstinence
9. c) Sweat
10. c) They maintain health and follow treatment

2. Matching Items Answers

List A	List B
Breastfeeding by HIV positive mother	b) Increases risk of HIV transmission
Proper condom use	a) Prevents new HIV infections
VCT services	d) A way to know HIV status
Sharing needles	f) Risky traditional practice
Abstinence	e) Sexual self-control
ARV drugs	c) Used to control HIV progression

SECTION B ANSWERS (54 Marks)

3a. Importance of VCT in preventing HIV spread

1. Identifies HIV-positive individuals who can take precautions
2. Provides opportunity for counseling about prevention
3. Encourages behavior change through awareness
4. Early detection allows for early treatment
5. Helps prevent mother-to-child transmission

3b. Two VCT detection methods

1. Rapid HIV tests (20-30 minute results)
2. ELISA test (laboratory antibody detection)

4a. Correcting misconceptions

1. HIV doesn't spread through hugging - no skin transmission
2. Eating together doesn't transmit HIV - not through saliva

4b. Modes of HIV transmission

1. Unprotected sexual intercourse
2. Mother-to-child transmission
3. Contact with infected blood
4. Use of unsterilized sharp objects

5a. Responsible sexual behavior examples

1. Abstinence
2. Mutual faithfulness
3. Consistent condom use

5b. Importance in HIV prevention

1. Abstinence eliminates sexual transmission risk
2. Faithfulness reduces exposure to multiple partners
3. Condoms create barrier against infected fluids

6a. ARVs and how they work

ARVs (Antiretroviral drugs) treat HIV by:

1. Inhibiting viral replication
2. Reducing viral load
3. Protecting CD4 cells
4. Preventing AIDS progression

6b. Importance of ARV adherence

1. Maintains consistent drug levels
2. Prevents drug-resistant strains
3. Ensures treatment effectiveness
4. Preserves immune function
5. Reduces transmission risk

7a. Purpose of pre-marital HIV testing

1. Informed relationship decisions
2. Early treatment if positive
3. Prevent partner transmission
4. Discuss mother-to-child prevention

7b. Benefits of knowing HIV status

1. Early treatment access
2. Take prevention precautions
3. Peace of mind if negative
4. Better family planning
5. Reduced anxiety

8a. Supporting HIV+ child's health

1. Ensure medical care and ARV adherence
2. Provide balanced nutrition
3. Maintain clean environment
4. Help child understand condition

8b. Importance of emotional support

1. Reduces stress that weakens immunity
2. Improves medication adherence
3. Prevents depression

SECTION C ANSWERS (30 Marks)

9. Social and economic impacts of HIV/AIDS

Family Level:

• Economic: Loss of income, medical expenses
• Social: Orphans, stigma, education disruption

National Level:

• Economic: Reduced productivity, healthcare costs
• Social: Overburdened systems, reduced life expectancy

10. HIV life cycle and cure challenges

Life Cycle:

1. Attachment to CD4 cells
2. Fusion with cell membrane
3. Reverse transcription
4. Integration into host DNA
5. Replication and assembly
6. Budding of new viruses

Cure Challenges:

• Integration into host DNA
• High mutation rate
• Latent reservoirs
• Immune system evasion

11. Tanzania HIV reduction strategies

1. Sex education: School programs teaching safe sex
2. VCT promotion: Mobile testing units
3. PMTCT: ARVs for pregnant women
4. Harm reduction: Needle exchange programs
5. Stigma reduction: Media campaigns