Heredity and evolution Worksheet-13

Heredity and evolution Worksheet-13


  1. What is a gene?


  1. Write the scientific term used for 'science of heredity and variation.'


  1. Define inheritance.


  1. Name the scientist who proposed the theory of natural selection.


  1. What are analogous organs?


  1. Name the naturalist who put forward the theory of natural selection along with Darwin.


  1. Give two examples of analogous organs from animals.


  1. What are homologous organs? Give one example.


  1. What term did Mendel use for what we now call the genes?


  1. List the main concepts in Darwin's theory of Natural Selection.


  1. What is heredity?


  1. Name the plant on which Mendel performed his experiments.


  1. Define Variation.


  1. What is micro-evolution?


  1. Write the expanded form of DNA.


  1. What do you understand by evolution?


  1. Who is called "Father of Genetics"?


  1. What are the carriers of factors or genes?


  1. Give an example of homologous organ from the plant kingdom.


  1. Why can the wings of a bird and the wings of a bat not to be considered analogous?



  1. Gene is the unit of inheritance. It is therefore, a unit of specific biological function. Gene is the part of a chromosome which controls the appearance of a set of hereditary characteristics.


  1. Genetics.


  1. Inheritance is the transmission of particular characteristics from generation to generation by means of the genetic code, which is transferred to offspring in the gametes.


  1. Charles Darwin.


  1. Analogous organs are those organs which have different basic structure and development origin

but have similar appearance and perform similar functions.

e.g., wings of an insect (butterfly) and a bird.


  1. Alfred Wallace.


  1. (i) Wings of insects and those of birds. (ii) Wings of insects and those of bats.


  1. Homologous organs are those organs which have the same basic structural design and

developmental origin but have different functions and appearance.

Example: The forelimb of a frog, a lizard, a bird and a man seem to be built from the same basic design of bones, but they perform different functions.


  1. Factors.


  1. Darwin explained evolution with the help of his theory of natural selection.


  1. Heredity refers to the transmission of characters or traits from the parents to their offspring.


  1. Garden Pea (Pisum sativum).


  1. Variation refers to the differences in the characters or traits among the individuals of a species.


  1. Micro-evolution is the evolution on a relatively small scale, involving the emergence of new species or of new groups below the species level, such as races and sub-species which are significant. They also change the common characteristics of a particular species.


  1. DNA - Deoxyribonucleic Acid.


  1. Evolution is the sequence of gradual changes which takes place in the primitive organisms over million of years in which new species are produced.


  1. Gregor Johann Mendel.


  1. Chromosomes.


  1. Thorns and tendrils.


  1. Wings of bird and a bat are modified forelimbs and hence show structural similarity. Hence they cannot be considered as analogous structures.