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!
Sterility in Angiosperms
Sterility in angiosperms may arise due to several causes. Either the anther may not be formed, or anthers are formed but meiosis may be abnormal.
A. In situations where anthers are not formed, they may take abortive forms and appear like petals or sepals. These conditions are referred to as petaloid and phyllody respectively. There are even cases where anther formation may be suppressed altogether. These cases of pollen sterility have premeiotic determination.
B. There are other examples in which anthers are produced but meiosis is abnormal resulting in the formation of non-viable pollen.
C. Sometimes normal pollen grains are formed but they are not released. This results from failure of anther dehiscence. Such a situation is also described by the term contabiscent anther.
D. Sometimes meiosis is normal but abortion can take place due to premature dissolution of callose. This can occur at any stage during microsporogenesis.
2 phases of oogenesis
Aortic Valve Repair : In, acquired AR associated with VSD and prolapse of a cusp, repair is often successful. VSD is closed and at the same time the prolapsed part o
Abrasive action of water, ice and wind Water is an important mechanical weathering agent both in liquid as well as in the frozen state. Rain water carrying sediments, ice glac
Q. How are bacteria are classified according to their need for oxygen? According to their need of oxygen bacteria are classified into anaerobic those that survive without oxyge
Q. What do you mean by Diabetes Mellitus? Diabetes Mellitus as you know is a metabolic disorder, which is characterized by high blood sugar. It is a chronic disease condition,
How do meiosis do in developing of new varieties of crops
Effects on Aquatic Organisms - Water Pollution Toxic water pollutants such as metals, pesticides, insecticides and chemicals affect aquatic species directly whereas the non-t
Explain in details Class Hirudenia - Leeches? This group includes the leeches. Most leeches grow in tropical freshwater habitats, and are familiar to most people as bloodsucker
Starch is a large molecule consisting of between 300 to 500 glucose molecules joined together. A glucose molecule is only very small, consisting of 24 atoms. Cellophane is simila
Q. Is the ventricle lumen larger during diastole or during systole? During diastole the opposite occurs. The muscle fibers of the ventricles relax and the lumen of these chambe
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