Alexander Von Humbolt described for the first time

  • Ecological Biodiversity

  • Laws of limiting factor

  • Species area relationships

  • Species area relationships


C.

Species area relationships

1218 Views

The amnion of mammalian embryo is derived from

  • ectoderm and mesoderm

  • endoderm and mesoderm

  • ectoderm and endoderm

  • mesoderm and trophoblast


A.

ectoderm and mesoderm

The extraembryonic or foetal membranes are amnion, chorion, allantois and Yolk sac.
Amnion is formed from mesoderm on the outer side and ectoderm on the inner side.
Chorion is formed from trophoectoderm and mesoderm whereas allantois and Yolk sac membrane have mesoderm on outer side and endoderm in the inner side.


Advertisement

Mycorrhizae are the example of

  • Fungistasis

  • Amensalism

  • Antibiosis

  • Antibiosis


D.

Antibiosis

785 Views

Advertisement

Annual migration does not occur in the case of

  • salmon

  • siberian crane

  • salamander

  • salamander


C.

salamander

Salamonder is semiterrestrial lizard-like tailed amphibian lives under stones, logs and inside crevices. They show hibernation.
Salmon anadromous i.e., they spend their adult lives at sea but return to fresh water to spawn.  The pacific species is legendary after migrating downstream as a smolt a sockeye salmon ranges many hundreds of miles over the pacific for nearly four year and than returns to spawn in the head waters of its parent stream.
Migration tern travels about 1100 miles during winter and return back during summer.

484 Views

Asymptote in a logistic growth curve is obtained when

  • The value of 'r' approaches zero

  • K = N

  • K > N

  • K > N


B.

K = N

A population growing in a habitat with limited resources shows logistic growth curve

3140 Views

Advertisement