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.
HAIR Presence of hair is main feature of mammals, absent in whale fish. Soft hair in embryo of animals are lanugo. Study of hair is tricology . Part of hair which
Normal 0 false false false EN-IN X-NONE X-NONE MicrosoftInternetExplorer4
Minerals :- Magnesium Food Source Whole grains, nuts, legumes, green leafy vegetables Nutritional Functional role Essential nutrient: Deficiency is rare Co
advantages of cuticle of anthropodes
Endocrine glands Endocrine glands have no ducts - so these are also called as ductless glands Eg.Pituitary etc., These glands secrete chemical substances called HORMONES
Why is the number of bonds important in nucleic acids
Q. What is Hydrogenqted Fat? All vanaspati preparations are the result of hydrogenation of oils, where unsaturated fat is converted to saturated fat for its favour and long she
Endocrine Regulation of the Cycle - Reproduction You have learnt above that the reproductive cycles are governed by the interplay of pituitary and gonadal hormones. According
Define Role in protein metabolism and growth? Severe vitamin A deficiency results in abnormal RNA metabolism and protein synthesis and hence interferes with growth. Hence vitam
Cancer Lung Incidence of cancer lung is more in persons who smoke. Environmental and industrial pollution is also a risk factor in the increase in incidence. Clinic
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