Evaluation
OCR A-Level Biology B H422
The Developing Cell: Cell Division and Cell Differentiation
The Developing Individual: Meiosis, Growth and Development
The Development of Species: Evolution and Classification
Cells and Microscopy
Topic overviewMicroscopy and the cell theoryBlood smears, staining and microscope drawingsBlood cells and their structureMagnification and measuring cellsHaemocytometer cell counts and dilutionsFlow cytometry in blood analysisUltrastructure of the animal cellPlant and prokaryotic cellsMembrane lipids and the fluid mosaic modelMovement of molecules across membranesThe roles of membranes and the secretion of proteins
Water and Its Importance in Plants and Animals
Proteins and Enzymes
Nucleic Acids
Patterns of Inheritance
Population Genetics and Epigenetics
Gene Technologies
The Principles and Importance of Homeostasis
The Hormonal Control of Blood Glucose and the Management of Diabetes
Kidney Functions and Malfunctions
Topic overviewExcretion and the gross structure of the kidneyThe nephron: ultrafiltration and selective reabsorptionInvestigating the composition of urine, plasma and filtrateOsmoregulation and the action of ADHThe kidney as an endocrine gland and kidney failureDialysis, transplantation and the future of transplant surgery
The Cellular Basis of Cancer and Treatment
Respiratory Diseases and Treatment
Cellular Respiration
Metabolism and Exercise
Topic overviewThe consequences of exercise on the bodyAerobic fitness and VO₂ maxTraining, F.I.T.T. factors and investigating fitnessEnhancing athletic performanceHaemoglobin and the transport of oxygenOxygen dissociation curves of different respiratory pigmentsOxygen deficit and oxygen debtThe structure of skeletal muscleThe sliding filament theory of muscle contraction
Pathogenic Microorganisms
The Immune System
Controlling Communicable Diseases
Photosynthesis, Food Production and Management of the Environment
Topic overviewChloroplast ultrastructure and photosynthetic pigmentsThe light-dependent stage of photosynthesisThe Calvin cycleInvestigating the factors affecting photosynthesisThe Hill reaction and DCPIPUsing TP and GP to build carbohydrates, lipids and amino acidsThe compensation point and crop productionMicroorganisms, the nitrogen cycle and biosensorsBiomass transfer and efficiency in food productionRuminants in the human food chainFarms as ecosystems and the conflict with conservationDeflected succession and measuring biodiversity
The Impact of Population Increase
Planning and Implementing Practical Work
Analysing and Evaluating Practical Results
Practical Skills, Apparatus and Techniques
Topic overviewInvestigative approaches and working safelyFollowing instructions, recording and presenting dataResearch, referencing and processing data with softwareMeasuring mass, volume, time, temperature, length and pHColorimeters and potometersLaboratory glassware and serial dilutionsLight microscopy, graticules and biological drawingQualitative reagents for biological moleculesChromatography and electrophoresisAseptic technique and dissectionWhole-organism responses, fieldwork sampling and data logging
Fertility and Assisted Reproduction
The Effects of Ageing on the Reproductive System
Plant Reproduction
The Nervous System and the Identification and Consequences of Damage
Topic overviewOrganisation of the nervous system and nervous tissueThe structure and function of the human brainThe structure of motor, sensory and relay neuronesResting potential and the action potentialSynapses and the integration of responsesReflexes, reaction times and their investigationBrain scans and the consequences of nervous system damageDrugs, brain function and dependency
Monitoring Visual Function
The Effect of Ageing on the Nervous System
The Heart and Monitoring Heart Function
Transport Systems in Mammals
Gas Exchange in Mammals and Plants
The Impact of Population Increase
- 4 subtopics
- 12 things to know
- Components 01, 02 and 03
What The Impact of Population Increase covers
The Impact of Population Increase is examined in all three written papers — the specification states that Components 01, 02 and 03 can each assess content from any of the five modules, so nothing is confined to one paper. It covers birth rate, death rate and demographic change, human impact on ecosystems and biodiversity, the importance and measurement of species biodiversity and global food security and sustainable food production.
Where it is assessed
Components 01, 02 and 03
Every module can be assessed on any of the three papers.
Check the OCR specification ↗The 4 subtopics
Each one has its own page.
- Birth rate, death rate and demographic changeRecall questions on how birth rate and natural increase are calculated, what has driven death rates down, why birth rate follows infant mortality, population pyramids, and the dependency ratio.Open →
- Human impact on ecosystems and biodiversityRecall questions on greenhouse gases, climate change and ocean acidification, soil degradation and salinisation from irrigation, water pollution and biochemical oxygen demand, habitat loss and fragmentation, introduced species such as the grey squirrel, overfishing, lost genetic diversity and declining pollinators.Open →
- The importance and measurement of species biodiversityRecall questions on species biodiversity, richness and evenness, calculating and comparing Simpson's Diversity Index, why diverse ecosystems are stable, ecosystem services, keystone species, and the economic, medical, agricultural, aesthetic and scientific reasons for conserving biodiversity.Open →
- Global food security and sustainable food productionRecall questions on food security and its four dimensions, threats from population, climate, soil loss and rising meat consumption, sustainable farming and reducing waste, food fraud and the horsemeat case, food crime and safety hazards, and the Food and Agriculture Organisation, its crisis framework and EMPRES.Open →
What you need to know
Answer each one before you reveal it.
Your recallNot started
Evaluation
How does a growing human population change the climate, pollute water and destroy habitats?
Evaluation
Why does the loss of species biodiversity matter to people?
Key term
What does food security depend on, what threatens it, and what makes food production sustainable?
Key term
How is the natural increase of a human population calculated?
Key term
Give two human activities that have raised the atmospheric carbon dioxide concentration.
Key term
Define species biodiversity.
Key term
What is meant by food security?
Numbers
A town of 40 000 people records 880 live births in a year. Calculate its birth rate.
Key term
Explain how a rise in atmospheric greenhouse gases raises the mean global temperature.
Key term
Distinguish between species richness and species evenness.
Key term
Name the four dimensions on which food security is usually assessed.
Take The Impact of Population Increase further
The same content, four other ways.
Commonly confused
Pairs that lose marks when they are blurred together.
Birth rate vs Fertility rate
Birth rate: the number of live infants delivered in a year for every 1 000 people in the whole population. Fertility rate: the average number of children born to each woman over her lifetime.
Habitat loss vs Habitat fragmentation
Habitat loss: the outright removal of an area of living space, for example by clearing land for farming or building, so the species there lose it entirely. Habitat fragmentation: the division of an area into small isolated patches, so populations can no longer interbreed and each patch is easily wiped out.
Exponential growth vs Logistic growth
Exponential growth: increase that accelerates continuously because nothing is yet limiting the rate at which numbers rise. Logistic growth: increase that slows and then levels off as numbers approach the maximum the environment can support.
Questions from this topic
Each one with the model answer underneath.
- 1
How is birth rate expressed when human populations are compared?
Model answer
It is expressed as the number of live births per 1 000 of the population per year.
- 2
How is the natural increase of a human population calculated?
Model answer
The death rate is subtracted from the birth rate, with any change caused by migration considered separately.
- 3
A town of 40 000 people records 880 live births in a year. Calculate its birth rate.
Model answer
The birth rate is 22 per 1 000 per year.
- 4
A population has a birth rate of 26 and a death rate of 8 per 1 000 per year. Calculate the annual percentage growth from natural increase.
Model answer
The natural increase is 18 per 1 000, which is a growth of 1.8% per year.
- 5
Explain how increased food production lowers the death rate of a population.
Model answer
A reliable food supply removes deaths from famine and reduces malnutrition, so people resist infection better and far more infants survive.
- 6
Give three advances in medical technology that have reduced human death rates.
Model answer
Vaccination programmes, antibiotics to treat bacterial infection, and improved antenatal and surgical care.
What is inside Levo
Six ways to work the same material.
The Impact of Population Increase revision questions
- What does The Impact of Population Increase cover in OCR A-Level Biology B?
- 4 subtopics: birth rate, death rate and demographic change, human impact on ecosystems and biodiversity, the importance and measurement of species biodiversity and global food security and sustainable food production. Each one has its own page with questions and model answers.
- How is The Impact of Population Increase organised?
- By the OCR H422 specification, subtopic by subtopic, so it matches the order you are taught it in.
Every question in The Impact of Population Increase, on a schedule.
Attempt a question from memory, write the correct version, then attempt it again. Levo records the jump between your first attempt and your last, and brings each question back on the day you are due to forget it.
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