Class 12 Biology - Chapter Organisms and Population NCERT Solutions | Name important defence mechanisms in pla
Name important defence mechanisms in plants against herbivory.
Several plants have evolved various mechanisms both morphological and chemical to protect themselves against herbivory.
(1) Morphological defence mechanisms:
(a) Cactus leaves (Opuntia) are modified into sharp spines (thorns) to deter herbivores from feeding on them.
(b) Sharp thorns along with leaves are present in Acacia to deter herbivores.
(c) In some plants, the margins of their leaves are spiny or have sharp edges that prevent herbivores from feeding on them.
(2) Chemical defence mechanisms:
(a) All parts of Calotropis weeds contain toxic cardiac glycosides, which can prove to be fatal if ingested by herbivores.
(b) Chemical substances such as nicotine, caffeine, quinine, and opium are produced in plants as a part of self-defense.
More Questions From Class 12 Biology - Chapter Organisms and Population
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- Q:-
Fill in the blanks:
(a) Humans reproduce __________. (asexually/sexually)
(b) Humans are__________. (oviparous/viviparous/ovoviviparous)
(c) Fertilization is __________ in humans. (external/internal)
(d) Male and female gametes are __________. (diploid/haploid)
(e) Zygote is __________. (diploid/haploid)
(f) The process of release of the ovum from a mature follicle is called__________.
(g) Ovulation is induced by a hormone called the __________.
(h) The fusion of male and female gametes is called _____________.
(i) Fertilisation takes place in _____________.
(j) Zygote divides to form _____________which is implanted in uterus.
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