Already have an account? Get multiple benefits of using own account!
Login in your account..!
Remember me
Don't have an account? Create your account in less than a minutes,
Forgot password? how can I recover my password now!
Enter right registered email to receive password!
Phototropism - Root and Shoot Morphogenesis
Paratonic growth movement of part of a plant in response to light, e.g. bending of stems of indoor plants towards a window, brought about by increased elongation of cells in growth region at tip of stem on shaded side. Coleoptiles of dark grown Avena seedlings bend towards light, when we provide unilateral light. The tip is found to be playing a role. Actually the tip is site of auxin production. If the tip is removed there is no response to unilateral light. But an agar block containing auxins can substitute for the tip and coleoptile would bend towards the light as if it had not been decapitated. The coleoptile bends towards light because of unequal elongation of cells on two sides. The cells on the darker side elongate faster than those cells on two sides exposed to light.
Generally accepted that effect is due to greater concentration of auxin on dark side than on side facing light but some recent evidence suggests asymmetric distribution of some co-factor that influences auxin effect. Shoots always bend and grow towards light. It is an adaptive mechanism, no doubt. Here, also the auxin is agents that mediate light control just as in coleoptile. One question that needs to be asked is whether the extent of phototropism is proportional to the duration of exposure to light. Secondly, whether the magnitude of curvature is proportional to the energy content of the inducing light.
Which gas in each of the following pairs would you expect to be more soluble in water? Why? (a) Oxygen and Carbon Dioxide (b) Nitrogen and Ammonia (c) Methane and Hydrogen Sulfide.
DESCRIBE ELECTRON TRANSPORT SYSTEM AND PHOTORESPIRATION
Q. Phylogenetic species concept ? Taxonomists (scientists who compare, classify and name organisms) tend to describe a species by studying their physical characteristics and be
A balanced diet must have enough energy to meet the body's needs. What else must it have? In addition to sufficient energy, a balanced diet must have proteins, car
what is vaso-constriction
How is light from the sun transformed into chemical energy to be used by the living beings on earth? Light from the sun is transmitted into chemical energy contained in organic
Pectin The word pectin is derived from a Greek word which means to "congeal or solidify". Pectin is an acidic structural polysaccharide, found in fruit and vegetables and mainl
Define Some Caution for Inoculating Loops and Needles? 1. Heat the inoculating wire till it becomes red hot. 2. Never use hot inoculating wire for culturing otherwise cells
Are nematodes exclusively parasites? There are parasitic roundworms, containing parasites of plants, but there are also free-living nematodes.
Mitral Valve Replacement : Patients who require surgery and are not candidates for BMV, CMV or OMV should have mitral valve replacement (MVR). Types of Surgery for Mitra
Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!
whatsapp: +91-977-207-8620
Phone: +91-977-207-8620
Email: [email protected]
All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd