CBSE Class 10   Class 10 Science

Planaria, insects, octopus and vertebrates all have eyes (1)
“Fossils are related to evolution”, justify this statement. Give the two ways by which age of the fossils can be estimated? (1)
. Explain the following:Speciation Natural Selection (1)
A pea plant with blue colour flower denoted by BB is cross-bred with a pea plant with white flower denoted by ww (1)
"Two areas of study namely ‘evolution’ and ‘classification’ are interlinked”. Justify this statement (1)
What are chromosomes? Explain how in sexually reproducing organisms the number of chromosomes in the progeny is maintained (1)
In one of his experiments with pea plants Mendel observed that when a pure tall pea plant is crossed with a pure dwarf pea plant, in the first generation (1)
List in tabular form, two distinguishing features between the acquired traits and the inherited traits with one example of each (1)
What is speciation? List four factors responsible for speciation (1)
Why is variation beneficial to the species but not necessary for the individual? (1)
How do variations occur in an offspring? (1)
‘Different species use different strategies to determine sex of a newborn individual (1)
“We cannot pass on to our progeny the experiences and qualifications earned during our life time”. Justify the statement giving reason and examples (1)
What is DNA copying? State its importance (1)
How many pairs of chromosomes are present in human beings? (1)
List two differences in tabular form between dominant trait and recessive traits (1)
A change in DNA that is useful for one property to start with, can become useful later for a different function. Explain (1)
All the human races like Africans, Asians, Europeans, Americans and others might have evolved from a common ancestor (1)
Does the occurrence of diversity of animals on earth suggest their diverse ancestry also? Discuss this point in the light of evolution (1)
A very small population of a species faces a greater threat of extinction than a larger population. Provide a suitable genetic explanation.? (1)
How does use and disuse of an organ help in evolution of a new species? (1)
Do genetic combination of mothers play a significant role in determining the sex of a new born? (1)
What is the contribution of Mendel to genetics? (1)
Give the pair of contrasting traits of the following characters in pea plant and mention which is dominant and recessive (1)
What are the causes of variations? (1)
Why offsprings differ from parents in certain characters? (1)
Reproduction is essentially a phenomenon that is not for survival of an individual but for the stability of a species. ?Justify (1)
Name the human male reproductive organ that produces sperms and also secretes a hormone. Write the functions of the secreted hormone (1)
Write the functions of the following in human female reproductive system (1)
State in brief the functions of the following organs in the human female reproductive system (1)