Genes, DNA, and Heredity
Inheritance Starts with DNA
DNA as biological information
DNA stores instructions for building and maintaining organisms. Genes are regions of DNA that influence traits, and different versions of a gene are called alleles.
Why variation exists
Offspring are not exact copies of their parents. Variation comes from mutation, recombination, and random assortment of alleles during reproduction.
Genetics basics
Genotype and phenotype
Genotype is the genetic code an organism carries; phenotype is the trait you can observe. The same genotype can sometimes produce slightly different phenotypes depending on the environment.
How traits are passed on
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Parents carry genes in their DNA.
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During reproduction, alleles are passed to offspring.
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Offspring inherit a combination of alleles.
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Those inherited alleles influence traits.
What is an allele?
An allele is one version of a gene.
Correct answer: A version of a gene
What is the difference between genotype and phenotype?
The answer should clearly separate inherited information from visible characteristics.
Correct answer: Genotype is an organism's genetic makeup, while phenotype is its observable traits.
Which process creates new genetic variation most directly?
Mutation changes DNA and can create new alleles.
Correct answer: Mutation