BIOLOGY Questions and Answers – SS1 – 3rd Term
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Table of Contents – Weekly Scheme of Work
- Week 1: Micro-Organisms Around Us and the Concept of Culturing
- Week 2: Micro-Organisms in Action
- Week 3: Sexually Transmitted Infections (STI)
- Week 4: Towards Better Health
- Week 5: Relevance of Biology to Agriculture
- Week 6: Pests and Diseases of Plants
- Week 7: Pests and Diseases of Animals
- Week 8: Food Storage and Production
- Week 9: Revision of Weeks 1–8
- Week 10: Mock Examination Practice
- Week 11: Further Revision and Corrections
- Week 12: Examination
40 Objective Questions
- Which of the following is NOT a characteristic of micro-organisms?
A. Microscopic in nature
B. Found only in laboratories
C. Capable of reproduction
D. Can be cultured - The process of growing micro-organisms in a nutrient medium is called:
A. Preservation
B. Fermentation
C. Incubation
D. Culturing - Which of the following is used in culturing bacteria?
A. Distilled water
B. Agar medium
C. Lime water
D. Salt solution - Which of these diseases is NOT sexually transmitted?
A. Gonorrhea
B. Malaria
C. Syphilis
D. HIV/AIDS - Which of the following symptoms is common to most STIs?
A. Loss of vision
B. Itching and unusual discharge
C. Headache only
D. Muscle cramps - Which of the following is a preventive measure against STIs?
A. Eating fresh food
B. Regular exercise
C. Practicing abstinence
D. Use of antibiotics only - Which organ is primarily affected by HIV/AIDS?
A. Liver
B. Immune system
C. Heart
D. Kidney - The best way to promote better health is by:
A. Avoiding all physical activities
B. Consulting native doctors
C. Practicing personal hygiene
D. Eating only carbohydrates - Which of the following is a vector of malaria?
A. Housefly
B. Anopheles mosquito
C. Tsetse fly
D. Cockroach - Which of these can be used to store grains?
A. Open containers
B. Nylon bags
C. Silos
D. Paper boxes - A pest is best defined as:
A. A friendly animal on the farm
B. A beneficial organism
C. An organism that destroys crops or animals
D. A kind of fungus - One of the effects of pests on crops is:
A. Increased productivity
B. Better taste
C. Poor growth
D. Delayed harvesting - Which of these micro-organisms is used in baking bread?
A. Virus
B. Bacteria
C. Protozoa
D. Yeast - The process by which yeast converts sugar to alcohol is called:
A. Oxidation
B. Photosynthesis
C. Fermentation
D. Transpiration - The bacteria used in milk production is:
A. Lactobacillus
B. Salmonella
C. Streptococcus
D. Bacillus anthracis - Which of the following is a disease of animals?
A. Rust
B. Anthrax
C. Blight
D. Smut - Which one of the following pests attacks both plants and animals?
A. Rodents
B. Beetles
C. Caterpillars
D. Weevils - The purpose of culturing micro-organisms is to:
A. Increase their size
B. Study their behavior
C. Kill them instantly
D. Mix them with soil - The major component in agar media is:
A. Sugar
B. Protein
C. Gelatin
D. Clay - Inadequate food storage can lead to:
A. Food exportation
B. Pest invasion
C. Fertilizer application
D. Growth stimulation - The organ attacked by tuberculosis is the:
A. Brain
B. Heart
C. Lungs
D. Kidney - Which of the following STIs is caused by a virus?
A. Syphilis
B. Chlamydia
C. HIV
D. Gonorrhea - One function of white blood cells is to:
A. Transport oxygen
B. Clot blood
C. Fight infections
D. Carry hormones - An example of plant disease is:
A. Rinderpest
B. Anthrax
C. Rust
D. Tuberculosis - One advantage of better health practices is:
A. Decrease in productivity
B. Poor sanitation
C. Reduced illness
D. Laziness - Which of the following micro-organisms is parasitic?
A. Algae
B. Virus
C. Mould
D. Yeast - Food preservation methods include all EXCEPT:
A. Drying
B. Smoking
C. Freezing
D. Sprouting - The use of chemicals to prevent food spoilage is called:
A. Salting
B. Pasteurization
C. Chemical preservation
D. Blending - Which of the following is NOT a reason for food storage?
A. Price stability
B. Prevent spoilage
C. Promote wastage
D. Continuous availability - The micro-organism that causes tuberculosis is:
A. Mycobacterium tuberculosis
B. Bacillus anthracis
C. Escherichia coli
D. Vibrio cholerae - Protozoa are classified as:
A. Animals
B. Fungi
C. Bacteria
D. Viruses - Which STI can lead to infertility if untreated?
A. HIV
B. Gonorrhea
C. Herpes
D. Measles - A micro-organism that helps in nitrogen fixation is:
A. Yeast
B. Clostridium
C. Rhizobium
D. Salmonella - Which of the following spreads cholera?
A. Mosquito
B. Housefly
C. Snail
D. Dog - Which agricultural practice helps reduce pests?
A. Overgrazing
B. Monocropping
C. Crop rotation
D. Bush burning - An example of viral STI is:
A. Syphilis
B. Chlamydia
C. Herpes
D. Gonorrhea - The part of the microscope used to adjust clarity is the:
A. Arm
B. Base
C. Coarse adjustment knob
D. Stage - The micro-organism that spoils bread is:
A. Amoeba
B. Yeast
C. Algae
D. Protozoa - The nutrient medium used for growing micro-organisms must be:
A. Acidic
B. Toxic
C. Sterile
D. Frozen - Which of these is NOT a sexually transmitted infection?
A. Hepatitis B
B. HIV
C. Tuberculosis
D. Syphilis
Theory Questions
- Explain the concept of micro-organisms and describe five ways in which they are beneficial to humans.
- With clear examples, discuss five harmful effects of micro-organisms on human health and the environment.
- What are sexually transmitted infections (STIs)? Identify and explain four common STIs, their symptoms, and one preventive measure for each.
- Define personal hygiene and explain five ways individuals can maintain personal and community health.
- Describe the role of biology in agriculture and explain how three biological techniques have improved crop or animal production.
- List five common pests of crops and explain two ways each pest causes damage to plants.
- Discuss five methods used in controlling plant diseases on the farm and explain the advantages and disadvantages of two of them.
- Differentiate between bacterial and viral diseases in farm animals. Provide two examples of each and how they can be prevented.
- What is food storage? Highlight five methods of food preservation and explain how each method prevents spoilage.
- Describe the steps involved in culturing micro-organisms in a biology laboratory and mention three safety precautions to follow during the process.
Objective Answers
- B — Micro-organisms are found everywhere, not just in laboratories.
- D — Culturing is the process of growing micro-organisms in nutrient media.
- B — Agar medium is commonly used to culture bacteria.
- B — Malaria is not sexually transmitted; it’s vector-borne.
- B — Itching and unusual discharge are common symptoms of STIs.
- C — Abstinence is one of the most effective ways to prevent STIs.
- B — HIV primarily affects the immune system.
- C — Personal hygiene plays a major role in maintaining better health.
- B — The Anopheles mosquito is the known vector of malaria.
- C — Silos are ideal for storing grains.
- C — A pest is an organism that destroys crops or animals.
- C — Pests hinder proper growth, affecting crop yields.
- D — Yeast is the micro-organism used in baking bread.
- C — Fermentation is the process where yeast converts sugar to alcohol.
- A — Lactobacillus helps in converting milk to yogurt and cheese.
- B — Anthrax is a disease that affects animals.
- A — Rodents damage both plants and stored animal feed.
- B — Culturing helps scientists study the behavior and growth of microbes.
- C — Agar medium contains gelatin to support growth.
- B — Poor food storage leads to pest invasion.
- C — Tuberculosis targets the lungs.
- C — HIV is the STI caused by a virus.
- C — White blood cells fight infections in the body.
- C — Rust is a common plant disease.
- C — Good health practices reduce illness and boost wellbeing.
- B — Viruses are parasitic and need a host to survive.
- D — Sprouting is not a preservation method; it indicates spoilage.
- C — Chemical preservation prevents food spoilage using additives.
- C — Food is stored to avoid wastage, not to promote it.
- A — Mycobacterium tuberculosis causes TB.
- A — Protozoa are single-celled organisms classified as animals.
- B — Untreated gonorrhea can cause infertility.
- C — Rhizobium fixes nitrogen in leguminous plants.
- B — Houseflies can transmit cholera by contaminating food.
- C — Crop rotation interrupts pest life cycles and reduces infestation.
- C — Herpes is a viral STI.
- C — The coarse adjustment knob focuses the microscope.
- B — Yeast spoils bread by fermenting sugars.
- C — A nutrient medium must be sterile to avoid contamination.
- C — Tuberculosis is not sexually transmitted.
THEORY ANSWERS – SS1 BIOLOGY 3RD TERM
- Explain what micro-organisms are and describe four harmful effects of micro-organisms.
Micro-organisms are tiny living organisms that are too small to be seen with the naked eye. They include bacteria, viruses, fungi, protozoa, and algae. While some are beneficial, many can be harmful.
Harmful effects:
- Disease causation: Some micro-organisms cause diseases in humans (e.g., tuberculosis by Mycobacterium tuberculosis), animals (e.g., anthrax), and plants (e.g., rust).
- Food spoilage: Fungi and bacteria can spoil food, making it unsafe for consumption.
- Damage to crops: Microbial pests like fungi and bacteria affect crop yield and quality.
- Contamination of water: Harmful microbes can pollute water, leading to waterborne diseases like cholera.
- Discuss five benefits of micro-organisms to humans.
- Food production: Yeast is used in baking and brewing, while bacteria like Lactobacillus aid yogurt production.
- Nitrogen fixation: Bacteria like Rhizobium help in converting atmospheric nitrogen into usable forms for plants.
- Decomposition: Micro-organisms decompose organic matter, enriching the soil.
- Biotechnology: Used in producing vaccines, enzymes, and antibiotics.
- Waste treatment: Bacteria help in treating sewage and industrial waste.
- Explain the term ‘Sexually Transmitted Infections’ (STIs) and list five examples.
STIs are infections transmitted through sexual contact with an infected person. They can be caused by bacteria, viruses, or parasites.
Examples include:
- Gonorrhea
- Syphilis
- HIV/AIDS
- Herpes
- Chlamydia
- Describe four preventive measures against STIs.
- Abstinence: Avoiding sexual activity prevents transmission.
- Faithfulness to one partner: Reduces the risk of infection.
- Use of protection: Condoms can help prevent transmission.
- Regular testing and treatment: Helps detect and treat infections early.
- Define pests and list five examples affecting agriculture.
Pests are organisms that damage crops, livestock, or stored products, reducing yield and causing economic loss.
Examples include:
- Weevils (stored grains)
- Caterpillars (leaves of crops)
- Locusts (cereal crops)
- Aphids (sap-sucking insects)
- Rodents (e.g., rats, affect both field and storage)
- Differentiate between plant diseases and animal diseases, with examples.
- Plant diseases affect crops and are caused by fungi, bacteria, or viruses. Example: Rust, smut.
- Animal diseases affect livestock and are caused by viruses or bacteria. Example: Anthrax, rinderpest.
- Explain food storage and give four methods used.
Food storage involves preserving food items in conditions that prevent spoilage and pest infestation.
Methods:
- Drying: Removes moisture to prevent microbial growth.
- Smoking: Preserves meat and fish using heat and smoke.
- Freezing: Low temperatures slow down microbial activity.
- Use of silos: Grains are stored in large containers that prevent pest access.
- Describe the role of micro-organisms in food spoilage.
Micro-organisms like bacteria and fungi cause food to rot, decay, or ferment by breaking down its nutrients. This process can change the smell, taste, and texture of food, making it unsafe to consume. - List five causes of poor health and suggest solutions to each.
- Poor sanitation: Solution – Promote hygiene practices.
- Contaminated water: Solution – Provide clean water sources.
- Lack of vaccination: Solution – Immunization campaigns.
- Poor diet: Solution – Nutrition education and access to healthy foods.
- Unsafe sexual practices: Solution – Sexual education and condom distribution.
- Explain the concept of nitrogen fixation and state its importance.
Nitrogen fixation is the process by which atmospheric nitrogen (N2) is converted into ammonia or other molecules usable by plants. It is carried out by bacteria like Rhizobium found in root nodules of legumes. This process enriches soil fertility and supports healthy plant growth.
