๐งฌ Genes & Chromosomes โ Summary
๐น What are Genes?
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Genes are segments of DNA (Deoxyribonucleic Acid).
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Each gene contains instructions to build proteins that control traits (like eye colour, height, etc.).
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Humans have 20,000โ25,000 genes.
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Genes are inherited from parents to offspring.
โก๏ธ Example: Gene for eye colour, blood type, or ability to roll the tongue.
๐น What are Chromosomes?
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Chromosomes are long, thread-like structures made of DNA and proteins.
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Found in the nucleus of cells.
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Humans have 46 chromosomes in total:
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23 pairs
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22 pairs are autosomes
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1 pair is sex chromosomes (XX for females, XY for males)
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โก๏ธ Chromosomes carry genes. So, genes are like sentences, and chromosomes are like books that store them.
๐น How Are They Related?
| Genes | Chromosomes |
|---|---|
| Part of DNA | Made up of DNA |
| Carry traits | Carry multiple genes |
| One gene = one instruction | One chromosome = many instructions |
๐น Key Concepts:
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Alleles: Different forms of a gene (e.g., brown vs blue eye colour)
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Genotype: Genetic makeup (what genes are present)
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Phenotype: Observable traits (how those genes show up)
๐ฏ Why Are They Important?
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Genes and chromosomes determine traits, control cell function, and play a key role in heredity.
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Mutations in genes or chromosomes can lead to genetic disorders.