Late blight of potato is caused by
Ustilago
Pseudomonas
Phytophthora infestans
Colletotrichum falcatum
Leaf abscission is caused by
ABA
cytokinin
auxin
gibberellin
A.
ABA
Abscission is the fall of leaves and fruits. Abscisic acid (ABA). a stress hormone, accelerated leaf abscission in cotton plants. Since, then it is believed that cause of abscission is the presence of growth inhibiting hormone (ABA), but its universal role for abscission is yet to be established.
Most accepted theory for ascent of sap is
capillarity theory
root pressure theory
pulsation theory
transpiration pull theory
Male Anopheles does not transmit malarial parasite because
it catches fever
it is too small to carry parasite
the parasite is killed in its stomach
it does not drink blood
The trisomy for 21st chromosome is called
Down's syndrome
Turner's syndrome
Sickle cell anaemia
Klinefelter's syndrome