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Heredity and Evolution — Science STD 10 — Question

CBSE BoardEnglish MediumSTD 10ScienceHeredity and Evolution5 Marks
Question
Give the basic features of the mechanism of inheritance.
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Answer

Basic Features of Inheritance:
  1. Unit Characters: An organism is made of a large number of characters, each of which behaves as a unit.
  2. Genes: Characters are controlled by genes.
  3. One Gene-One Character: A single gene generally controls one character.
  4. Location of Genes: Genes are located on chromosomes.
  5. Alleles: A gene may have two or more forms called alleles. They represent different traits of a character.
  6. Paired Alleles: An individual possesses two alleles of every gene. The two may be similar or dissimilar.
  7. Dominance: Where there are two different forms or alleles of the gene, generally one expresses its effect. It is called dominant allele. The other which does not express its effect in presence of dominant allele, is called recessive allele.
  8. Segregation: The two alleles separate at the time of gamete formation. A gamete has only one allele or form of the gene.
  9. Independent Assortment: The alleles of different genes located on separate chromosomes behave independent of one another.
  10. Pairing: Fusion of gametes during fertilization, brings together the two forms of a gene in the zygote.

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