Biology Today — January 2018
DARWIN’S THEORY OF NATURAL SELECTION Charles Darwin, an English naturalist and one of the most dominant biologists of 19th cent ...
Table : Observations and inferences of principle of natural selection Observations Inferences (i) All species have such great po ...
Table : Differences between Hugo de Vries’ mutation and Darwinian variation Hugo de Vries’ mutation Darwinian variation (i) Muta ...
Sickle cell anaemia The sickle cell gene produces a variant form of the protein haemoglobin, which differs from the normal haemo ...
The two formulae are – p^2 + 2pq + q^2 = 1, p + q = 1 where, p = Frequency of the dominant allele in the population q = Freque ...
Evolution of Vertebrates Pelycosaurs (extinct) Early reptiles (extinct) 350 300 250 200 150 100 50 Quaternary Tertiary Cretaceou ...
EVOLUTION OF MAN Homo sapiens sapiens Period : 25,000 years ago (Holocene) Location : First appeared around Caspean and Mediterr ...
Webbed toes of aquatic birds support (a) Neo-Lamarckism (b) Lamarckism (c) Darwinism (d) Neo-Darwinism. Identify the correct se ...
Read the following statements and select the correct option. Statement A : Reproductive isolation gives rise to parapatric spe ...
Total Marks : 160 Time Taken : 40 Min. T his specially designed column enables students to self analyse their extent of understa ...
Choose the wrongly matched pair. (a) Simplipal - Odisha (b) Periyar Sanctuary - Tiger (c) Khasi and Jaintia hills - Meghalaya ( ...
An area is declared as “Hotspot” when (a) it has 1500 or more endemic species and 75% of its original habitat is lost (b) it ha ...
(i) Active cooperation is present between reserve management and local people for settlements and cropping. (ii) In this region ...
SECTION - A Define standing crop and standing state. Write two different ways for the disposal of e-wastes. Mammals Y X ...
What are the causes of global warming? Also explain why is it a warning to mankind. OR Compare narrowly utilitarian and broadly ...
(iv) Application of stringent pollution level norms for vehicles Differences between in situ and ex situ conservation are as fo ...
(ii) Overgrazing : The livestock graze in forest trampling seedlings and cause soil compaction. This reduces water storing capac ...
(ii) By burning of fossil fuels: Fossil fuels like coal, petroleum and natural gas are rich source of carbon. On burning, they r ...
Glucose is not stored in plant due to (a) decrease in osmotic pressure (b) increase in osmotic pressure (c) increase in turgor ...
Which of the following is used to determine the rate of transpiration in plants? (a) Porometer (b) Potometer (c) Auxanometer (d ...
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