Heredity and evolution Worksheet-18

Heredity and evolution Worksheet-18

 

  1. How human evolution took place over the years?

 

  1. Explain Mendel's experiment with peas on inheritance of traits considering only one visible contrasting character.

 

  1. Explain Mendel's experiment with peas on inheritance of traits considering two visible contrasting characters.

 

  1. Explain with an example how traits get expressed.

 

  1. Draw a schematic diagram to explain the independent inheritance of two separate traits, shape and colour of seeds.

 

  1. How do homologous characteristic help to identify an evolutionary relationship between different species?

 

  1. Explain the importance of variations.

 

  1. On the basis of the possibilities of combination of the sex chromosomes, what percentage probability does a couple have of having a son or a daughter? Show the same by making a cross.

 

  1. What is a sex chromosome? Name the two types of sex chromosomes. Mention the sex chromosomes present in males and females.

 

  1. Explain with an example how variation took place due to inheritance.

 

  1. 'Non-living-material must have given rise to life'. Describe with an example.

 

  1. What role does sexual reproduction play in evolution?

 

  1. How do Mendel's experiment show that traits may be dominant or recessive?

 

  1. How do Mendel's experiments show that traits are inherited independently?

 

  1. How is the sex of the child determined in human beings?

 

  1. What are the different ways in which individuals with a particular trait may increase in a population?

 

  1. Will geographical isolation be a major factor in the speciation of a self-pollinating plant species? Why or why not?

 

  1. Will geographical isolation be a major factor in the speciation of an organism that reproduces asexually? Why or why not?

 

  1. Give an example of characteristics being used to determine how close two species are in evolutionary terms.

 

  1. In evolutionary terms, can we say which among bacteria, spiders, fish and chimpanzees have a 'better' body design? Why or why not?

 

  1. 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?

 

  1. How are the areas of study - evolution and classification - interlinked?

 

  1. Explain the terms analogous and homologous organs with examples.

 

  1. Explain the importance of fossils in deciding evolutionary relationships.

 

  1. Explain how sexual reproduction gives rise to more viable variations than asexual reproduction. How does this affect the evolution of those organisms that reproduce sexually?

 

  1. (i) What is 'genetics'?

(ii) Give the common name of the plant on which Mendel performed his experiments.

 

  1. (i) What are 'chromosomes'? Where are they located in the cells?

(ii) What is a sex chromosome?

(iii) Explain the mechanism of sex determination in human beings.

OR

(i) Analogous organ

(ii) Natural selection

 

  1. What are fossils? How does the study of fossils provide the evidence in favour of Organic Evolution?

 

  1. What are homologous organs? How do they differ from analogous organs? How does the study of comparative anatomy provide evidence in favour of Organic Evolution?

 

  1. How is the sex of a new born individual determined? Explain with the help of a diagram.

 

  1. Explain with example how characteristics of a population changes over the years for the following situations

(a) To gain survival advantage

(b) Due to accidental survival

(c) Temporary change of characteristics.

 

  1. What are fossils? What do they tell us about the process of evolution?