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North CarolinaBiology

Heredity: Inheritance and Variation of Traits

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

How does meiosis produce gametes and create genetic variation?

Explain how meiosis produces gametes with half the chromosome number and generates genetic variation (North Carolina Standard Course of Study, Biology, LS.Bio.6).
A standard-level answer on meiosis for the North Carolina Biology EOC: how meiosis halves the chromosome number, the role of crossing over and independent assortment, and why sexual reproduction creates variation.
13 min answer →

How do Punnett squares predict the genotype and phenotype ratios of a cross?

Use mathematics and Punnett squares to predict the genotype and phenotype ratios and probabilities of monohybrid crosses (North Carolina Standard Course of Study, Biology, LS.Bio.7).
A standard-level answer on inheritance for the North Carolina Biology EOC: alleles, genotype and phenotype, dominant and recessive, and using Punnett squares to predict the ratios and probabilities of monohybrid crosses.
13 min answer →

How do inheritance patterns beyond simple dominance produce a range of phenotypes?

Explain patterns of inheritance beyond simple dominance, including incomplete dominance, codominance, multiple alleles, and polygenic traits (North Carolina Standard Course of Study, Biology, LS.Bio.7).
A standard-level answer on non-Mendelian inheritance for the North Carolina Biology EOC: incomplete dominance, codominance, multiple alleles in ABO blood type, and polygenic traits, with how to tell them apart.
13 min answer →

Why do sex-linked traits affect males more often, and how do we read a pedigree?

Analyze sex-linked inheritance and interpret pedigrees to trace traits through generations (North Carolina Standard Course of Study, Biology, LS.Bio.7).
A standard-level answer for the North Carolina Biology EOC on sex-linked inheritance and pedigrees: why X-linked recessive traits appear more in males, carriers, and how to read a pedigree chart.
13 min answer →

How can the environment influence the way genes are expressed in an organism?

Explain how environmental factors can influence the expression of an organism's genetic traits (North Carolina Standard Course of Study, Biology, LS.Bio.7).
A standard-level answer for the North Carolina Biology EOC on how the environment shapes traits: the interaction of genotype and environment, examples such as plant height and coat color, and inherited versus acquired traits.
12 min answer →