Unit 1, try it
The ability of the nervous system to monitor and respond to changes depends on:
Press a choice to see the answer.
Prepare for the national exam in Form 4 Biology with 1,887 questions written from the school book, unit by unit. Practise the units you choose with every answer explained, or sit a full timed test and see honestly whether you are ready.
What you get
- No question twice: You are given new questions until you have seen them all. Only then do the ones you got wrong return.
- Every answer explained: A short reason with each answer, and the page of the book to read again.
- A full timed test: Questions from the whole book against the clock, with no answers shown until you hand in.
- An honest verdict: Ready, close or not yet, for each unit. It is only given once you have answered enough for it to mean something.
Units and lessons
Lesson 1: The Nervous Tissue
- Introduction to the nervous system
- Nervous tissue
- Structure of the neuron
Lesson 2: Types of Neurons
- Types of neurons by structure
- Types of neurons by function
- Nerves
Lesson 3: Nerve Impulse
- Nerve impulse
- Resting potential
- Action potential
Lesson 4: The Synapse and Neurotransmitters
- The synapse
- Neurotransmitters
Lesson 5: Structure of the Nervous System
- Parts of the nervous system
Lesson 6: The Central Nervous System
- The central nervous system
- The meninges
- The brain
- The cerebrum
- Functional areas of the cerebrum
- The diencephalon
- The brain stem
- The cerebellum
- Dissection of the brain
- The spinal cord
- Reflex action
Lesson 7: Peripheral Nervous System
- Cranial and spinal nerves
- The somatic nervous system
- The autonomic nervous system
Lesson 8: Health Problems of the Nervous System
- Diseases of the nervous system
Lesson 9: The Senses
- Taste and smell
- Sight
- Hearing and balance
- Touch
Lesson 1: Structure of the Endocrine System
- Introduction to the endocrine system
- Endocrine and exocrine glands
- Classification of hormones and mechanism of action
- Lipophilic and hydrophilic hormones
- Feedback mechanisms
- Antagonistic hormones
- Endocrine glands and their hormones
- Pituitary gland
- Pancreas
- Thyroid gland
- Parathyroid glands
- Adrenal glands
- Gonads
- Diabetes
- Abnormalities in thyroid activity
- Growth hormone disorders
- Chapter questions
Lesson 0: Chapter 3 questions (skeletal and muscular parts of the chapter review)
- Chapter 3 questions
Lesson 1: Structure of the skeletal system
- Introduction to the skeletal, muscular and integumentary systems
- Types of skeletons
- Parts of skeletal system
- The axial skeleton
- The skull
- The vertebral column
- The thoracic cage
- The appendicular skeleton
Lesson 2: Types of bones
- Types of bones
Lesson 3: Structure of bones
- Extracellular matrix
- Compact bone
- Spongy bone
- Structure of bones
- Formation of bone
- Cartilage
Lesson 4: Joints
- Types of joints
- Joint structure
Lesson 5: Functions of the skeletal system
- Functions of the skeletal system
Lesson 6: Health complications that affect the skeletal system
- Bone fracture
- Arthritis
Lesson 7: Muscular system
- Muscular system
- Types of muscles
- Skeletal muscles
Lesson 8: Mechanism of muscle contraction
- Mechanism of muscle contraction
- Sliding filament theory
Lesson 9: Muscular movement of bones
- Flexor and extensor muscles
- Slow twitch and fast twitch muscle fibers
Lesson 10: Health complications of muscles
- Muscle cramps
- Muscle fatigue
- Muscle strain
- Muscle tearing
Lesson 11: The Integumentary System
- The integumentary system
- The structure of skin
- The epidermis
- The dermis
- Functions of the skin: protection
- Functions of the skin: regulation of body temperature
- Functions of the skin: formation of vitamin D
- Functions of the skin: sensation
- Functions of the skin: excretion
- Glands of the skin
- Hairs
- Nails
- Skin disorders
- Eczema
- Acne
- Chapter 3 questions: skin
Lesson 1: The Discovery of the Genetic Material (DNA)
- Chapter 4 introduction
- The discovery of the genetic material (DNA)
Lesson 2: The Structure of the Chromosome
- The structure of the chromosome
Lesson 3: The Nucleic Acids
- The nucleic acids
- Nucleotides
- Deoxyribonucleic acid (DNA)
- Questions on the structure of DNA
- Chapter 4 questions
Lesson 4: The Importance of Nucleic Acids
- The importance of nucleic acids
- Chapter 4 questions
Lesson 5: The DNA Replication
- The cell cycle
- The mechanism of DNA replication
- The importance of DNA replication
- Chapter 4 questions
Lesson 6: Mutations
- Mutations
- Types of mutations
Lesson 7: Protein Synthesis (Transcription and Translation)
- Flow of genetic information
- Types of RNA and their functions
Lesson 8: Stages of Protein Synthesis
- Transcription
- RNA processing
- The genetic code
- The codons of the mRNA
- Translation
- The structure of the ribosome
- Translation: initiation
- Translation: elongation
- Translation: termination
- Post translational modifications
- Chapter 4 questions
Lesson 1: Mendelian Genetics
- Chapter 5 introduction
- Mendelian genetics
- Mendel's results and probabilities
Lesson 2: Laws of probability
- The rule of multiplication
- The rule of addition
- Applications of the law of addition
Lesson 3: Law of independent assortment
- Law of independent assortment
- Three characteristics and forked lines
- Chapter questions
Lesson 4: Test cross
- Test cross
- Performing a test cross
- Chapter questions
Lesson 5: Complex inheritance patterns
- Incomplete dominance
- Codominance
- Codominance: sickle cell
- Multiple alleles
- Rh factor
- Blood transfusion
- Polygenic inheritance
- Chapter questions
Lesson 6: Sex determination system in living organisms
- Sex determination system
- Sex linked traits
- Duchenne muscular dystrophy
- Sex influenced traits
- Chapter questions
Lesson 7: Genetic maps
- Genetic maps
- Crossing over and recombinant gametes
- Scientific thinking: maize experiment
- Chapter questions
Lesson 8: Genetic disorders
- Genetic disorders
- Gene mutations
- Alteration in chromosome structure
- Krabbe disease
- Phenylketonuria
- Nondisjunction
- Aneuploidy
- Polyploidy
- Chapter questions
Lesson 9: Applied genetics
- Selective breeding
- Hybridization
- Inbreeding
Lesson 1: Biotechnology
- Introduction to biotechnology
- Biotechnology
- Genetic engineering
- Chapter review
Lesson 2: Techniques used in genetic engineering
- Techniques used in genetic engineering
- Restriction enzymes
- Gel electrophoresis
- Recombinant DNA technology
- Medical products of recombinant DNA
- Gene cloning
- DNA sequencing
- Polymerase chain reaction
- Steps of PCR
- DNA fingerprinting
- Summary of major tools in genetic engineering
- Chapter review
Lesson 3: Transgenic organisms
- Transgenic organisms
- Transgenic animals
- Transgenic plants
- Transgenic bacteria
- Applications of biotechnology
- Medical applications
- Gene therapy
- Genomics and proteomics
- Pharmaceutical products
- Environmental cleanup
- Agricultural applications
- Bioethics
Lesson 1: Biodiversity
- Introduction
- Definition of biodiversity
- Genetic diversity
- Species diversity
- Ecosystem diversity
- Chapter review
Lesson 2: The importance of biodiversity
- Reasons to preserve biodiversity
- Direct economic value
- Indirect economic value
Lesson 3: Threats to biodiversity
- Extinction rates
- Factors that threaten biodiversity
- Overexploitation
- Habitat loss
- Pollution as a threat
- Biological magnification
- Acid precipitation
- Eutrophication
- Measuring biodiversity
Lesson 4: Conserving biodiversity
- Conservation biology
- Natural resources
Lesson 5: Protecting biodiversity
- Protected areas in Somalia
- Chapter review
Lesson 6: Environmental problems
- Pollution
- Air pollution
- Sulphur based chemicals
- Oxides of nitrogen
- Primary and secondary pollutants
- Smoke and fumes
- Dust
- Aerosols
- Water pollution
- Domestic effluents
- Industrial effluents
- Heat
- Oil spillage
- Agro-chemicals
- Lead and mercury
- Soil erosion
- Soil pollution
- Solid waste
- Radioactive emissions
National exam past papers
The real Form 4 national exams of past years. Take one against the clock, then see every answer explained.
- National exam 2024/202562 questions, 100 marks, 120 minutes
- National exam 202462 questions, 100 marks, 120 minutes
- National exam 202251 questions, 100 marks, 120 minutes
- National exam 202136 questions, 100 marks, 120 minutes
- National exam 202042 questions, 100 marks, 120 minutes
- National exam 201840 questions, 100 marks, 120 minutes
Most tested in the national exam
The units the past papers asked about most, by marks. Revise these first.
- Unit 5. Genetics121 marks
In 6 of 6 papers: 2018, 2020, 2021, 2022, 2024, 2024/2025
- Unit 2. The Endocrine System115 marks
In 6 of 6 papers: 2018, 2020, 2021, 2022, 2024, 2024/2025
- Unit 1. The Nervous System and Sense Organs96 marks
In 6 of 6 papers: 2018, 2020, 2021, 2022, 2024, 2024/2025
- Unit 3. The Skeletal, Muscular and Integumentary Systems85 marks
In 6 of 6 papers: 2018, 2020, 2021, 2022, 2024, 2024/2025
- Unit 7. Biodiversity and environmental problems80 marks
In 6 of 6 papers: 2018, 2020, 2021, 2022, 2024, 2024/2025
- Unit 4. The Genetic Material and Protein Synthesis70 marks
In 6 of 6 papers: 2018, 2020, 2021, 2022, 2024, 2024/2025
- Unit 6. Biotechnology32 marks
In 5 of 6 papers: 2018, 2021, 2022, 2024, 2024/2025
A course that goes with this subject
Pharmocolgy
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The practice is free whether or not you take a course.
Sample questions
Unit 2, try it
The endocrine system consists of:
Press a choice to see the answer.
Unit 3, try it
The integumentary system consists of:
Press a choice to see the answer.
Unit 4, try it
What gives different organisms different characteristics?
Press a choice to see the answer.
Questions students ask
Is the exam preparation really free?
Yes. Practice and the full timed test are free and stay free. You only need a free account, so that your answers and your progress are saved.
Where do the questions come from?
Every question is written from the Form 4 student book used in schools, unit by unit and lesson by lesson. Each answer shows the book page it comes from, so you can go back and read it.
Are these past exam papers?
No. These are practice questions that follow the book, not copies of past government papers. They train you on everything the book covers, so you know the material whatever is asked.
Will I see the same question again?
Not until you have been given every question in the units you chose. After that, the ones you got wrong come back first.
How do I know I am ready?
After 20 answers in a unit you get a verdict for that unit. Ready means 75 percent or more in every unit, not only a good average. The full timed test shows how you do under exam conditions.
Can I use it on my phone?
Yes. It works in the browser of any phone. There are no videos to load: a question, its choices and the explanation.
Do I have to buy a course?
No. The practice does not depend on any course. Now and then we suggest one course that fits how you are doing. You can ignore it.
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1,887 practice questions in 7 units
