Question : 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 ?

Question : Consider the following statements. (i) Polyspermy may brin

1.	Question : 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 ?
Answer» (i) and (IV) (i) and (iii) (ii) and (iii) (ii) and (iv) SOLUTION :In angiosperms, the POLLEN tube is normally an unbranched structure which collapses soon after fertilisation, the pollen tube may persist for as long as three weeks. Morphologically, the exine is diviside into two distinct layers (i) an outer suclptured layer CALLED sexine, and (ii) an INNER non-sculptured layer, nexine.