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!
Geotropism - Root and Shoot Morphogenesis
Roots always grow towards gravity. The lot threshold of geotropic response requires as little time as one minute Gravity pulls auxin to lower side, causing promotion of growth of root tip and elongation. Ethylene induced by auxins also play a role in geotropism. Immediate transient release of ethylene is often part of geotropic response. There are special crystals in plant cells which are heavy enough to perceive gravity. These crystals move towards the direction of gravity and exert a pressure on those of sides of cells, perhaps stimulating a series of changes including auxin production influencing the growth of cells in the direction of gravitation field.
i) Perception: How does a plant part detect direction of the environmental stimulus that causes the tropism? Where in the plant is located the perception mechanism? It has been difficult to answer these questions for plants, because, in contrast to animals, they do not have specific organs for each function.
ii) Transduction: Whatever be the mechanism of perception. How does it convert or transduce it into a message of stimulus direction to the cells in the organ where tropistic movement occurs? What metabolic or growth regulator changes occur in response to the environmental stimulus? This has been an especially active area of research in biology.
iii) Response: What actually happens during tropistic bending or other responses? Any hypothesis put forth to explain the mechanism of perception and transduction must account for the observed response. Yet the details of each response have been rather neglected for the past few decades-until quite recently. Early researches in the late 1800s and early 1900s made many careful studies of tropistic responses, discovering that cells on one side of the organ grow more than those on the other side, accounting for bending. The result of early workers were either overlooked or completely forgotten, and are beginning to be appreciated for their significance.
Sexual Reproduction All metazoans, if or if not capable of propagating asexually, produce special cells termed as gametes. The gametes may be either male gametes or sperms or
Size of Ecosystem As you know an ecosystem may be as small and as simple as a cow dung pad or as complex and large as an ocean or the biosphere itself, comprising a wide variet
At 1 AM, a healthy squid giant axon is placed in a bath of normal squid physiological extracellular saline and is internally perfused with normal squid intracellular saline.
Q. Important aspect of dietary management during hypertension? Most important aspect of dietary management i.e. the intake of minerals and electrolytes, which are closely assoc
Third Week - Embryonic Development Throughout the third week of development the ICM separates from the uophoblast and forms the flattened embryonic disc, which at first consi
Excretory organ of crustaceans and agama lizard
Q. Assets and capital stock accounts? At the present extend the liabilities, assets and capital stock accounts in the Adjusted Trial Balance columns to the Balance Sheet column
Aim of Diabetes Counselling Diabetes is a life-long illness. Diagnosis of diabetes has psychological and physical implications. Preventive counselling and life style change ca
Explain different modes nutrition like Autotroph,hetrotroph,saprotroph,holozoic
State three main ways in which the body uses food. The body uses food (i) for energy, (ii) for growth (making new cells), (iii) repairing or replacing tissues.
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: +1-415-670-9521
Phone: +1-415-670-9521
Email: [email protected]
All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd