Will geographical isolation be a major factor in the speciation of an organism that reproduces asexually? Why or why not?
Asexual reproduction occurs during the formation of two daughter cells from one parent only. There will be no variation when there is only one parent involved. And, where there is no variation speciation cannot occur. As in the self pollinating flowers geographical isolation is not the major factor in the speciation, this can also be seen in the case of asexual reproducing organisms. Where there is no variation, competition or genetic recombination, speciation will not occur and as well as geographical isolation will not occur because it refers to the separation of group of related organisms by some barriers.
Outline a project which aims to find the dominant coat colour in dogs.
How is the sex of the child determined in human beings?
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?
How do Mendel’s experiments show that traits are inherited independently?
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?
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?
Explain the terms analogous and homologous organs with examples.
How do Mendel’s experiments show that traits may be dominant or recessive?
How does the creation of variations in a species promote survival?
Why are traits acquired during the life-time of an individual not inherited?
Did Döbereiner’s triads also exist in the columns of Newlands’ Octaves? Compare and find out.
What is a good source of energy?
Why is diffusion insufficient to meet the oxygen requirements of multi-cellular organisms like humans?
What are trophic levels? Give an example of a food chain and state the different trophic levels in it.
What changes can you make in your habits to become more environment-friendly?
What is the difference between a reflex action and walking?
What is the importance of DNA copying in reproduction?
Why should a magnesium ribbon be cleared before burning in air?
Define the principal focus of a concave mirror.
You have been provided with three test tubes. One of them contains distilled water and the other two contain an acidic solution and a basic solution, respectively. If you are given only red litmus paper, how will you identify the contents of each test tube?
Explain the underlying principle and working of an electric generator by drawing a labelled diagram. What is the function of brushes?
Which signals will get disrupted in case of a spinal cord injury?
An electric bulb is rated 220 V and 100 W. When it is operated on 110 V, the power consumed will be –
(a) 100 W (b) 75 W (c) 50 W (d) 25 W
The device used for producing electric current is called a
(a) generator.
(b) galvanometer.
(c) ammeter.
(d) motor.
If all the waste we generate is biodegradable, will this have no impact on the environment?
The far point of a myopic person is 80 cm in front of the eye. What is the nature and power of the lens required to correct the problem?
What are the differences between autotrophic nutrition and heterotrophic nutrition?
An object 5.0 cm in length is placed at a distance of 20 cm in front of a convex mirror of radius of curvature 30 cm. Find the position of the image, its nature and size.
An object of size 7.0 cm is placed at 27 cm in front of a concave mirror of focal length 18 cm. At what distance from the mirror should a screen be placed, so that a sharp focussed image can be obtained? Find the size and the nature of the image.
What is a balanced chemical equation? Why should chemical equations be balanced?