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Northern IrelandCombined Science

B2 Body Systems, Genetics, Microorganisms and Health

8 dot points across 8 inquiry questions. Click any dot point for a focused answer with worked past exam questions where available.

How is genetic information stored in DNA, and how does it control an organism?

The relationship between the nucleus, chromosomes, genes and DNA, the structure of DNA as a double helix with complementary base pairs, the human chromosome number, and how a gene codes for a protein.
A focused CCEA GCSE Double Award Science (Biology Unit B2) answer on genetic material, covering the relationship between the nucleus, chromosomes, genes and DNA, the double helix and complementary base pairs, the human chromosome number, and how a gene codes for a protein.
8 min answer →

How do antibiotics work, why is resistance a problem, and how do drugs affect health?

How antibiotics treat bacterial but not viral infections, the problem of antibiotic resistance and how to reduce it, how new medicines are tested, and the effects of legal and illegal drugs including alcohol and tobacco.
A focused CCEA GCSE Double Award Science (Biology Unit B2) answer on medicines and drugs, covering how antibiotics treat bacterial not viral infections, antibiotic resistance and reducing it, how new medicines are tested, and the effects of alcohol, tobacco and other drugs on health.
7 min answer →

What are microorganisms, how does the body defend against disease, and how do vaccines work?

The main types of microorganism and their useful roles, pathogens and how they spread, the body's first-line defences, the role of white blood cells in phagocytosis and antibody production, and how vaccination gives immunity.
A focused CCEA GCSE Double Award Science (Biology Unit B2) answer on microorganisms and defence, covering the types of microorganism and their uses, pathogens and how they spread, first-line defences, white blood cells and phagocytosis and antibodies, and how vaccination provides immunity.
8 min answer →

What are the two types of cell division, and what is each one for?

Mitosis as cell division producing two genetically identical cells for growth and repair, meiosis as division producing four genetically different gametes with half the chromosome number, and why meiosis creates variation.
A focused CCEA GCSE Double Award Science (Biology Unit B2) answer on cell division, covering mitosis producing identical cells for growth and repair, meiosis producing four different gametes with half the chromosome number, and why meiosis creates variation.
7 min answer →

How are characteristics inherited, and how is the sex of a baby determined?

The terms gene, allele, dominant, recessive, homozygous, heterozygous, genotype and phenotype, using Punnett squares for a monohybrid cross, how the X and Y chromosomes determine sex, and how a genetic disorder such as cystic fibrosis is inherited.
A focused CCEA GCSE Double Award Science (Biology Unit B2) answer on inheritance, covering the key genetics terms, Punnett squares for monohybrid crosses, how the X and Y chromosomes determine sex, and how a recessive disorder such as cystic fibrosis is inherited.
8 min answer →

What is osmosis, and how do plants move water and food around?

Osmosis as the movement of water across a partially permeable membrane, turgid, flaccid and plasmolysed plant cells, the roles of xylem and phloem, water uptake by root hair cells, and transpiration and the factors affecting it.
A focused CCEA GCSE Double Award Science (Biology Unit B2) answer on osmosis and plant transport, covering osmosis across a partially permeable membrane, turgid, flaccid and plasmolysed cells, xylem and phloem, root hair cells, and transpiration and its factors.
8 min answer →

How does blood move around the body, and how is the heart and each blood vessel adapted?

The components of the blood and their functions, the structure of the heart with its chambers and valves, the double circulatory system, the structure and adaptations of arteries, veins and capillaries, and the effect of lifestyle on heart health.
A focused CCEA GCSE Double Award Science (Biology Unit B2) answer on the circulatory system, covering the components of blood, the structure of the heart and its valves, the double circulation, the adaptations of arteries, veins and capillaries, and lifestyle effects on heart health.
8 min answer →

Where does variation come from, and how does natural selection lead to evolution?

Continuous and discontinuous variation and their genetic and environmental causes, the role of mutation, the theory of evolution by natural selection, antibiotic resistance as an example, and the evidence from fossils.
A focused CCEA GCSE Double Award Science (Biology Unit B2) answer on variation and evolution, covering continuous and discontinuous variation, genetic and environmental causes, mutation, natural selection, antibiotic resistance as an example, and fossil evidence.
8 min answer →