The pH indicator phenol red is used for monitoring the status of the medium. This will change from red at pH 7.2–7.4 to yellow or fuchsia as the pH becomes either acidic or alkaline, respectively.

TLS Online TPP Program

#Id: 936

#Unit 5. Developmental Biology

Precursor cell (or simply precursors), is widely used to denote any ancestral cell type (either stem cell or progenitor cell) of a particular lineage.

TLS Online TPP Program

#Id: 937

#Unit 5. Developmental Biology

Inner cell mass (ICM) cells of the mouse blastocyst are maintained in a pluripotent state through E-cadherin interactions with trophectoderm cells that activate the Hippo kinase cascade and repress the function of Yap/Taz as transcriptional regulators of Cdx2.

TLS Online TPP Program

#Id: 938

#Unit 5. Developmental Biology

Induced pluripotent stem cell (iPSC) with the pluripotency of an embryonic stem cell. These genes were 

a. Sox2 and Oct4 (Oct3, Oct3/4, and Pou5f1) -which activated Nanog and other transcription factors that   established pluripotency and blocked differentiation

b. c-Myc which opened up chromatin and made the genes accessible to Sox2, Oct4, and Nanog

c. Klf4 -which prevents cell death

TLS Online TPP Program

#Id: 939

#Unit 5. Developmental Biology

In drosophila, the stem cells for sperm reside in a regulatory microenvironment called the hub.

TLS Online TPP Program

#Id: 940

#Unit 5. Developmental Biology

The mode of fertilization in sea urchin being external, the egg and spermatozoa are released into the sea water.

TLS Online TPP Program

#Id: 4733

#Unit 5. Developmental Biology

A stem cell retains the ability to divide and re-create itself while also having the ability to generate progeny capable of specializing into a more differentiated cell type.