Tapetum layer around pollen sacs is meant for :

Embryo sac is :

Tapetum occurs in :

Study of pollen grains is called

What is pollen grain ?

Callase enzyme which dissolved callose of pollen tetrads to separate four pollens is provided by

Express in one word only Pollen sac is known as.

Study of pollen grain is called:

Pollen 'sac in Cycas is called:

Consider the following statements. (i) Polyspermy may bring about fertilisation of egg by more than one male nucleus or the supernumerary sperms may fertilise other components of embryo sac much as synergids or antipodals. (ii) In angiosperms, pollen tube is normally an unbranched structure which ususally persists after fertilisation. (iii) Intine is the inner, pectocellulosic layer of pollen grain wall which is destroyed during acetolysis. (iv) Exine layer of pollen grain comprises of an outer non-sculptured layer sexine and an inner sculptured layer tectum. Which of the following combinations of above given statements is correct ?

Assertion : A typical microsporangium of angiosperms is generally surrounded by four wall layers - epidermis, endothecium, middle layers and tepetum. Reason : The outer three wall layers perform the function of protection and help in dehiscence of anther to release the pollen.