Heredity in Science

Updated on November 21, 2025 | By Learnzy Academy

Heredity is the process by which traits or characteristics are passed from parents to their offspring. It is the reason why offspring resemble their parents and inherit specific features.

Key Points:

  • Genes and DNA control inheritance.
  • Dominant traits (e.g., brown eyes) are expressed if one allele is present.
  • Recessive traits (e.g., blue eyes) are expressed only when both alleles are recessive.
  • Mendel’s Laws describe how traits are inherited:
  • Segregation – each parent passes one allele for a trait.
  • Independent Assortment – genes for different traits are inherited separately.

Example: Eye color inheritance – brown eyes (dominant) vs blue eyes (recessive).

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List of question on "Heredity"

  1. How is the equal genetic contribution of male and female parents ensured in the progeny?
  2. A study found that children with light-coloured eyes are likely to have parents with light-coloured eyes. On this basis, can we say anything about whether the light eye colour trait is dominant or recessive? Why or why not?
  3. A Mendelian experiment consisted of breeding tall pea plants bearing violet flowers with short pea plants bearing white flowers. The progeny all bore violet flowers, but almost half of them were short. This suggests that the genetic make-up of the tall parent can be depicted as (a) TTWW (b) TTww (c) TtWW (d) TtWw
  4. How is the sex of the child determined in human beings?
  5. A man with blood group A marries a woman with blood group O and their daughter has blood group O. Is this information enough to tell you which of the traits – blood group A or O – is dominant? Why or why not?
  6. How do Mendel’s experiments show that traits are inherited independently?
  7. How do Mendel’s experiments show that traits may be dominant or recessive?
  8. How does the creation of variations in a species promote survival?
  9. If a trait A exists in 10% of a population of an asexually reproducing species and a trait B exists in 60% of the same population, which trait is likely to have arisen earlier?