GCSE Biology B (Triple) OCR
Full course content, a smart revision plan and instant past paper feedback for GCSE Biology B (Triple) OCR.
Start revising this course →Content Overview
78 topics in 7 modules
☑️ Genes 10 topics
- Cells and Genetic Material
- Cells and Microscopes
- Genomes
- DNA
- Protein Synthesis
- Mutations and Genetic Variants
- Genetic Diagrams
- Mendel
- Genome Research and Testing
- Genetic Engineering
☑️ Keeping Healthy 13 topics
- Health and Disease
- How Diseases Spread
- Defending Against Pathogens
- The Human Immune System
- Reducing and Preventing the Spread of Disease
- Vaccinations
- Detecting Diseases
- Culturing Microorganisms
- Monoclonal Antibodies
- Non-Communicable Diseases
- Treating Disease
- Treating Cardiovascular Disease
- Developing New Medicines
☑️ Food and Ecosystems 17 topics
- Enzymes
- Photosynthesis
- Rate and Limiting Factors of Photosynthesis
- Diffusion, Osmosis and Active Transport
- Transport in Plants and Prokaryotes
- Xylem and Phloem
- Stomata
- Transpiration Rate
- Using a Potometer
- Ecosystems and Organism Interactions
- Factors Affecting Distribution
- Food Chains and Food Webs
- Pyramids of Biomass and Number
- Biomass Transfer
- Biological Molecules
- Ecosystems Cycles
- Decomposition
☑️ Food and Growth 6 topics
- Respiration
- The Cell Cycle and Mitosis
- Microscopy
- Sexual Reproduction and Meiosis
- Stem Cells
- Plant Growth
☑️ The Human Body 15 topics
- Exchange of Materials
- Human Exchange Surfaces
- The Circulatory System
- Blood Vessels
- Blood
- The Nervous System
- The Brain
- Hormones and Negative Feedback
- Hormones in Reproduction
- Hormones for Fertility and Contraception
- Homeostasis
- Controlling Water Content
- Controlling Blood Sugar Level
- The Eye
- Correcting Vision Defects
☑️ Life on Earth 8 topics
- Natural Selection and Evolution
- Evidence for Evolution
- Selective Breeding
- Darwin and Wallace
- Asexual and Sexual Reproduction
- Classification
- Biodiversity
- Human Food Security
☑️ Ideas About Science 9 topics
- The Scientific Method
- Designing Investigations
- Collecting Data
- Processing and Presenting Data
- Units and Equations
- Uncertainties and Evaluations
- Drawing Conclusions
- New Technologies and Risk
- Communication and Issues Created by Science
GCSE Biology B (Triple) OCR Revision Content
Take a look at the written content available for this course. Practice-question availability may vary.
GCSE Biology B (Triple) OCR - Genes - Cells and Genetic Material Content Preview
Genes
Cells and Genetic Material
Cells and Their Structure
- Cells are the basic building blocks of all living organisms.
- Each cell contains a nucleus, cytoplasm, and cell membrane.
- The nucleus controls the activities of the cell and contains chromosomes, which are made of DNA.
Chromosomes and Genes
- Chromosomes are long, coiled strands of DNA.
- Genes are sections of DNA that carry instructions for building an organism, including specific traits like hair colour or blood type.
- The human body has 23 pairs of chromosomes, totalling to 46.
DNA and Its Structure
- DNA (Deoxyribonucleic Acid) is a large molecule that contains all the genetic information for an organism.
- DNA is made up of two strands coiled into a double helix structure.
- Each strand consists of a sequence of four types of nucleotides: adenine (A), thymine (T), guanine (G), and cytosine (C).
- Adenine always pairs with thymine and guanine always pairs with cytosine, forming the 'rungs' of the DNA ladder.
Genetic Variation and Mutation
- Genetic variation arises from sexual reproduction, where chromosomes from two parents mix to produce offspring with unique combinations of genes.
- Mutations are changes in genes or chromosomes that can lead to new characteristics. These can be caused by errors in copying DNA during cell division, exposure to radiation, or exposure to certain chemicals.
- Some mutations can be beneficial and contribute to evolution, while others can lead to genetic disorders or diseases.
Genotype and Phenotype
- An organism’s genotype is the set of genes it carries, while its phenotype is its observable characteristics.
- The phenotype results from the interaction between the genotype and the environment.
Cell Division
- There are two types of cell division: mitosis and meiosis.
- Mitosis results in two identical daughter cells and is responsible for growth and repair in the body.
- Meiosis produces four non-identical daughter cells (gametes) used for sexual reproduction.
- During meiosis, the chromosomes pair up and exchange sections of DNA - this is known as "crossing over" and contributes to genetic variation.
Question: Which process of cell division results in four non-identical daughter cells and contributes to genetic variation by executing "crossing over" of paired chromosomes?
Unlock instant, personalised feedback
Sign up to Adapt to practise the exam questions available for this course with instant, personalised feedback.
Start revising this course →Try Adapt now
Add this exact course and build your personalised revision plan.