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Northern IrelandBiology

Genetics and Cell Division

5 dot points across 5 inquiry questions. Click any dot point for a focused answer with worked past exam questions where available.

How is genetic information stored in chromosomes, genes and DNA?

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 genes control the characteristics of an organism.
A focused CCEA GCSE Biology answer on chromosomes, genes and DNA, covering how they relate to the nucleus, the double helix and complementary base pairing, the human chromosome number, and how genes control characteristics.
8 min answer →

What is the difference between mitosis and meiosis, and why does each matter?

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 Biology answer on cell division, covering mitosis producing identical cells for growth and repair, meiosis producing genetically different gametes with half the chromosome number, and why meiosis creates variation.
8 min answer →

How do we predict the inheritance of a single characteristic using genetic crosses?

The terms gene, allele, dominant, recessive, homozygous, heterozygous, genotype and phenotype, and using Punnett squares to predict the ratios and probabilities of offspring in a monohybrid cross.
A focused CCEA GCSE Biology answer on monohybrid inheritance, covering the key genetic terms, dominant and recessive alleles, genotype and phenotype, and using Punnett squares to predict offspring ratios and probabilities.
9 min answer →

How does a gene code for a protein inside the cell?

How the base sequence of a gene codes for the order of amino acids in a protein, the roles of transcription and translation, the part played by mRNA and ribosomes, and how mutations can change a protein.
A focused CCEA GCSE Biology answer on protein synthesis, covering how the base sequence of a gene codes for amino acids, the roles of transcription and translation, mRNA and ribosomes, and how mutations can change a protein.
8 min answer →

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

How the X and Y sex chromosomes determine sex, using a genetic cross to show the equal chance of a boy or girl, and how genetic disorders such as cystic fibrosis are inherited from carrier parents.
A focused CCEA GCSE Biology answer on sex determination and genetic disorders, covering the X and Y chromosomes, the genetic cross showing equal chances of a boy or girl, and how disorders such as cystic fibrosis are inherited from carriers.
8 min answer →