The following questions refer to the figure below, which shows an outcrop of sedimentary rock whose strata are labeled A-D. If x indicates the fossils of two closely related species, neither of which is extinct, then their remains may be found in how many of these strata?

TLS Online TPP Program

#Question id: 15281

#Unit 5. Developmental Biology

What is morphogen?

TLS Online TPP Program

#Question id: 15282

#Unit 5. Developmental Biology

what is the difference between morphogen and morphogenetic determinants?

TLS Online TPP Program

#Question id: 15283

#Unit 5. Developmental Biology

Following are certain statements regarding

morphogen gradients and cell specification.

A. Morphogens are always transcription factors

B. Morphogens can be paracrine factors that are produced in one group of cells and travel to another population of cells

C. When the concentration of a morphogen drops below a certain threshold, cells stop differentiating and never get determined to another fate

D. Morphogen gradients are involved in conditional specification

Which combination of the above statements is true?

TLS Online TPP Program

#Question id: 15284

#Unit 5. Developmental Biology

Morphogens can be:

1. Transcription factors

2. Paracrine factors

3. Cell adhesion factors

4. Non-diffusable molecules

TLS Online TPP Program

#Question id: 15285

#Unit 5. Developmental Biology

The range of a paracrine factor (and thus the shape of its morphogen gradient) not depends on:

TLS Online TPP Program

#Question id: 15286

#Unit 5. Developmental Biology

In the case of the French flag model. we assume a source of morphogen at one end and a sink at the other and that the concentrations of morphogen at both ends are kept constant but are different from each other. If the cells can respond to threshold concentrations of the morphogen, Thresholds can represent the