TLS Online TPP Program

#Question id: 7101


What is the mechanism by which cells fated to be mesoderm form in the marginal zone of the Xenopus embryo?

#Unit 5. Developmental Biology
  1. Cells in the marginal zone are fated to be mesoderm, but they do not become specified or determined as mesoderm until after they move internally during gastrulation.
  2. Cells of the vegetal region are induced by their proximity to the animal region cells to become mesoderm.
  3. Maternal factors packaged into the marginal zone act on these cells to instruct them to become mesoderm.
  4. Secreted signals of the TGF- family are released by the cells of the vegetal region and act on the adjacent cells of the marginal zone to instruct them to adopt a mesodermal fate.
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TLS Online TPP Program

#Question id: 10689

#Unit 10. Ecological Principles

Which of the following is correct statement?

A) Body size of parasitoid is always greater than host but parasite usually smaller than host

B) Predator immediately kill their prey however parasitoid never kill their host

C) Intrinsic rate of parasite is faster than host but intrinsic rate of predator is slower than prey

D) Body association time between parasite and host is more than time association between predator and prey

TLS Online TPP Program

#Question id: 10690

#Unit 10. Ecological Principles

Which of following interaction shown in following species of Paramecium?



TLS Online TPP Program

#Question id: 10691

#Unit 10. Ecological Principles

Following some attributes of biological control agent of parasite

A) General adaptability to the environment.

B) High searching capacity for hosts.

C) K selected strategy

D) Low dispersal ability.

E) Minimal time lag effects in responding to changes in host numbers.

Following above attribute is not ideal for that biological agent?

TLS Online TPP Program

#Question id: 10692

#Unit 10. Ecological Principles



TLS Online TPP Program

#Question id: 10693

#Unit 10. Ecological Principles

The diagram represents competition between species 1 and species 2 according to Lotka-Volterra model of competition


Given the conditions in the diagram, the predicted outcome of competition is


TLS Online TPP Program

#Question id: 10694

#Unit 10. Ecological Principles

Which of the following is characteristic of parasitoid/ predators?

a) consumer usually larger than resource

b) Consumer requires one host for complete development.

c) Habitat independent

d) Consumer takes long time to kill host

e) Consumer never kills their host

f) Host is free living

Which of the following is feature of parasitoid?