BGCSE Biology Revision Worksheet - First 100 Questions Answered
CELLS AND CELL PROCESSES
1. An Animal Cell
Label the following parts: nucleus, nuclear membrane, ribosome, mitochondrion,
cell membrane, cytoplasm.
Functions:
o Nucleus: Controls cell activities, contains genetic material (DNA), directs
protein synthesis.
o Ribosome: Site of protein synthesis.
o Mitochondrion: Produces energy via respiration.
o Cell membrane: Regulates movement of substances in and out of the cell.
2. A Plant Cell
Label the following parts: nucleus, nuclear membrane, ribosome, mitochondrion,
cell membrane, cytoplasm, chloroplasts, vacuole.
Functions:
o Chloroplast: Contains chlorophyll for photosynthesis.
o Vacuole: Stores nutrients and waste, provides cell structure.
3. Similarities and Differences Between Plant and Animal Cells
Similarities:
1. Both have a nucleus.
2. Both have mitochondria.
3. Both have ribosomes.
4. Both have a cytoplasm.
5. Both have a cell membrane.
Differences:
o Plant cell has a cell wall, animal cell does not.
o Plant cell has chloroplasts, animal cell does not.
o Plant cell has a large central vacuole, animal cell has small vacuoles.
o Animal cells are more rounded, plant cells are rectangular.
o Animal cells store glycogen, plant cells store starch.
4. A Root Hair Cell
Function: Absorbs water and minerals from the soil.
Adaptations:
o Large surface area for absorption.
o Thin membrane for easy water intake.
o Contains many mitochondria for active transport.
5. A Palisade Cell
Function: Carries out photosynthesis.
Adaptations:
o Contains many chloroplasts.
o Positioned near the upper surface of the leaf to receive more light.
o Has a large surface area to absorb maximum light.
6. A Red Blood Cell
Function: Transports oxygen in the body.
Adaptations:
o Biconcave shape for increased surface area.
o Lacks a nucleus to carry more hemoglobin.
o Flexible membrane for movement through capillaries.
o Contains hemoglobin which binds to oxygen.
7. A Nerve Cell
Function: Transmits electrical signals in the body.
Adaptations:
o Long axons for signal transmission.
o Myelin sheath for insulation.
o Branched dendrites to connect with other neurons.
8. A Sperm Cell
Function: Fertilizes the egg.
Adaptations:
o Tail for movement.
o Many mitochondria for energy.
o Acrosome contains enzymes to penetrate the egg.
Tissues, Organs, Systems
9. Define Tise
A group of similar cells working together to perform a function.
10. Examples of Animal and Plant Tissues
Animal: Muscle, blood, nervous tissue.
Plant: Xylem, phloem, epidermis.
11. Function of Xylem
Transports water and minerals in plants.
Adaptations:
o Hollow tubes for water flow.
o Thick walls for support.
o Lignified walls to prevent collapse.
12. Function of Phloem
Transports sugars in plants.
Adaptations:
o Companion cells provide energy.
o Sieve plates allow nutrient flow.
13. Define Organ
A group of tissues working together to perform a function.
Examples:
o Animal: Heart, lungs, liver.
o Plant: Leaves, roots, flowers.
14. Define Organ System
A group of organs working together to perform a function.
Examples:
o Digestive system
o Circulatory system
o Respiratory system
DIFFUSION AND OSMOSIS
15. Define Diffusion
Movement of molecules from a region of high concentration to low concentration.
16. Factors Affecting Diffusion Rate
Concentration Gradient: Greater gradient = faster diffusion.
Particle Size: Smaller particles = faster diffusion.
Membrane Thickness: Thinner membrane = faster diffusion.
Temperature: Higher temperature = faster diffusion.
17. Examples of Diffusion in Living Organisms
Animals: Oxygen into blood, carbon dioxide out of blood.
Plants: Carbon dioxide into leaves, oxygen out of leaves.
18. Define Osmosis
Movement of water across a semi-permeable membrane from a dilute to a
concentrated solution.
19. Effects of Osmosis on Plant Cells
Distilled Water: Cell becomes turgid.
Concentrated Sugar Solution: Cell becomes plasmolysed.
20. Effects of Osmosis on Animal Cells
Distilled Water: Cell bursts (lysis).
Concentrated Sugar Solution: Cell shrinks (crenation).
ACTIVE TRANSPORT
21. Define Active Transport
Movement of molecules against a concentration gradient using energy.
22. Define Passive Transport
Movement of molecules without energy.
23. Differences Between Active and Passive Transport
Active Transport Passive Transport
Requires energy No energy required
Moves against gradient Moves down gradient
Requires transport proteins May or may not require proteins
(Additional questions answered in document format.)
DIVERSITY OF ORGANISMS
24. Kingdoms of Organisms in Botswana
Kingdoms & Examples:
o Monera: Bacteria (e.g., Streptococcus)
o Protista: Amoeba, Plasmodium
o Fungi: Mushrooms, yeast
o Plantae: Baobab tree, grass
o Animalia: Lion, fish
25. Differences Between Bacterium and Virus
Feature Bacterium Virus
Structure Cell wall, DNA Protein coat, RNA/DNA
Reproduction Binary fission Requires host
Metabolism Yes No
Example E. coli Influenza virus
26. Differences Between Protozoa and Bacterium
Feature Protozoa Bacterium
Cell Type Eukaryotic Prokaryotic
Nucleus Present Absent
Example Amoeba Streptococcus
27. Differences Between Green Algae and Bacterium
Feature Green Algae Bacterium
Photosynthesis Yes Some do (e.g., cyanobacteria)
Cell Type Eukaryotic Prokaryotic
28. Differences Between Fungus and Green Algae
Feature Fungus Green Algae
Chlorophyll Absent Present
Mode of Nutrition Heterotrophic Autotrophic
29. Characteristics of Arthropoda
Exoskeleton
Segmented body
Jointed appendages
Bilateral symmetry
Open circulatory system
30. Characteristics of Vertebrates
Endoskeleton
Vertebral column
Bilateral symmetry
Closed circulatory system
Advanced nervous system
31. Characteristics of Angiosperms
Flowering plants
Produce seeds in fruits
Have vascular tissues
Undergo double fertilization
Exhibit alternation of generations
MALARIA
32. Role of Protozoa and Mosquitoes in Malaria
Protozoa: Plasmodium infects red blood cells.
Mosquitoes: Anopheles mosquitoes transmit Plasmodium.
33. Control of Malaria
Preventing mosquito breeding (e.g., draining stagnant water)
Using insecticides
Using mosquito nets
Taking anti-malarial drugs
NUTRITION
34. Autotrophic Nutrition
Organisms synthesize their own food (e.g., plants via photosynthesis).
35. Heterotrophic Nutrition
Organisms consume organic material (e.g., animals, fungi).
36. Forms of Heterotrophic Nutrition
Holozoic: Ingestion of solid food (e.g., humans)
Parasitic: Lives off host (e.g., tapeworms)
Saprophytic: Feeds on dead matter (e.g., fungi)
PLANT NUTRITION
37. Importance of Leaf Structure
Chloroplasts: Photosynthesis
Stomata: Gas exchange
Vascular Bundles: Transport
38. Photosynthesis Equation
Word Equation: Carbon dioxide + Water → Glucose + Oxygen
Chemical Equation: 6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂
39. Factors Affecting Photosynthesis
Light intensity
Carbon dioxide concentration
Temperature
TRANSPORT IN PLANTS
40. Differences Between Monocot and Dicot Stems
Feature Monocot Dicot
Vascular Bundles Scattered Arranged in rings
41. Function and Adaptation of Xylem
Function: Water transport
Adaptation: Hollow tubes, lignified walls
42. Function and Adaptation of Phloem
Function: Sugar transport
Adaptation: Sieve plates, companion cells
DIGESTIVE SYSTEM
43. Define Digestion Stages
Ingestion: Taking in food
Digestion: Breaking down food
Absorption: Nutrient uptake
Assimilation: Nutrients used by body
Egestion: Elimination of waste
44. Identify Digestive System Parts
Mouth, esophagus, stomach, intestines, rectum, anus
45. Functions of Digestive Organs
Organ Function
Stomach Acidic digestion
Small intestine Absorption of nutrients
Large intestine Water absorption
RESPIRATION
46. Define Respiration
Process of breaking down glucose to release energy.
47. Types of Respiration
Aerobic: Uses oxygen, produces CO₂ and water.
Anaerobic: No oxygen, produces lactic acid/alcohol.
48. Differences Between Aerobic and Anaerobic Respiration
Feature Aerobic Anaerobic
Oxygen Required Yes No
Products CO₂, Water Lactic Acid/Alcohol
49. Role of Liver in Metabolism
Glucose storage (as glycogen)
Detoxification of harmful substances
GENETICS
50. Define Terms
Gene: Segment of DNA coding for a protein.
Chromosome: DNA structure carrying genes.
Mutation: Change in genetic material.
51. Types of Cell Division
Mitosis: Produces identical cells for growth.
Meiosis: Produces gametes for reproduction.
52. Differences Between Mitosis and Meiosis
Feature Mitosis Meiosis
Cell Division 1 2
Produces 2 Diploid Cells 4 Haploid Cells
53. Define Inheritance
Transmission of genetic traits from parents to offspring.
54. Define Dominant and Recessive Alleles
Dominant: Expressed in heterozygous state.
Recessive: Expressed only in homozygous state.
55. Define Genotype and Phenotype
Genotype: Genetic makeup.
Phenotype: Observable traits.
