DNA Genes Chromosomes

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What is DNA?

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DNA (Deoxyribonucleic Acid) is the molecule that carries the genetic instructions for life. It is composed of two strands that coil around each other to form a double helix.

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What are chromosomes?

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Chromosomes are long, thread-like structures made of DNA and proteins that contain genes. Humans have 23 pairs of chromosomes.

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What is the relationship between DNA and chromosomes?

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Chromosomes are made of DNA.

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What are genes?

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Genes are small segments of DNA that contain the instructions for making proteins, which determine traits.

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How many genes do humans have?

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Humans have approximately 20,000 to 25,000 genes.

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What is a trait?

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A trait is a characteristic or feature of an organism, such as eye color or height, that is determined by genes.

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What is a nucleotide?

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A nucleotide is the basic building block of DNA, consisting of a sugar, a phosphate group, and a nitrogenous base.

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What is a genome?

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A genome is the complete set of genetic material in an organism, including all of its genes.

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What is a chromatid?

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A chromatid is one half of a duplicated chromosome, which is joined to the other half by a centromere.

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What is a mutation?

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A mutation is a change in the DNA sequence that can lead to changes in traits or functions.