Category: Botony
How do plants know when to flower?
Phytochrome, a blue-green pigment, is part of a switching mechanism for phototropic responses to light of red and far-red wavelengths. Its active form, Pfr might trigger the secretion of one or more hormones that induce and inhibit flowering at different times of yeat. The main environmental cue for flowering is the length of night, i.e.…
Q & A on living world and taxonomy
Q1. Who is known as the Darwin of the 20th century Ernst Mayr(1940) – During the mid 20th century, Ernst Mayr was one of the ‘architects’ of the synthetic theory of evolution. He proposed Biological concept of species, on the basis of interbreeding Q2. In unicellular organisms the ……………. is synonymous with growth. In unicellular…
ANGIOSPERMS (FLOWERING PLANTS)
Angiosperms are most dominant and most evolved plants on this earth, appeared about 130 million years ago in Jurassic (dicot plant) and cretaceous (monocot plants) period of the Mesozoic era. Tertiary period of Cenozoic era is called as Age of angiosperms. Angiosperms are found in every habitat. They constitute more than 50% of the total…
Symbiosis
A symbiosis is an evolved interaction or close living relationship between organisms from different species, usually with benefits to one or both of the individuals involved. Symbioses may be ‘obligate’, in which case the relationship between the two species is so interdependent, that each of the organisms is unable to survive without the other, or…
