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.
explain why expired air contain co2
CAT assay is an enzyme assay. CAT stands for the chloramphenicol acetyl transferase, a bacterial enzyme which inactivates the chloramphenicol by acetylating it. CAT assays are man
newer trends of animal taxonomy
A genetic trait which is considered to be harmful in the present day might prove to be beneficial in future. For example by removing the trait for sickle cell we may increase the s
mitochondria?
Vertical Implant Position: The implant can be submerged in the bone up till the level, where it is surface treated or further embedded till its shoulder, depending upon the sit
Describe about the extra-ocular muscles The extra-ocular muscles are mainly involved in the maintenance of postural tonicity and performance of quick contractions. The prima
Glanders The glanders is caused by Burkholderia mallei (previously known as Malleomyces mallei) and it is a serious contagious disease of equines. Infected equidae are the reservo
Define about the Hyponatremia and Hypernatremia? Serum concentration of sodium is normally regulated within the range of 135 to 145 milimole per litre (a). Hyponatremia is defi
assignment on 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