Data, collected from DNAs of a great many different species, led Chargaff to the following conclusions:

A. The base composition of DNA generally varies from one species to another.

B. DNA specimens isolated from different tissues of the same species have the different base composition.

C. The base composition of DNA in a given species changes with an organism’s age, nutritional state, or changing environment.

D. In all cellular DNAs, the sum of the purine residues equals the sum of the pyrimidine residues.

Which of the above statements are INCORRECT regarding Chargaff’s rule?

#Question id: 7010

#Unit 5. Developmental Biology

After anchor cell formation, When LIN-12 is used again during vulva formation, it is activated by the primary vulval lineage to

#Question id: 7011

#Unit 5. Developmental Biology

The vertebrate brain and spinal cord start their development as a flat plate of neuroepithelial cells that folds up along most of its length to form a tube. The process of forming this neural tube is called neurulation. Which of the following signals play important role in both neurulation and cell fate patterning of neural tube?

#Question id: 7012

#Unit 5. Developmental Biology

The differentiated cells divide but maintain their differentiated functions. The new cells do not come from stem cells, nor do they come from the dedifferentiation of the adult cells. Each cell produces cells similar to itself; no mass of undifferentiated tissue forms. This type of regeneration is:

#Question id: 7013

#Unit 5. Developmental Biology

In Drosophila development, cell membranes do not form until after the:

#Question id: 7014

#Unit 5. Developmental Biology

Microglia are often considered the “immune cells” of the central nervous system, since they function:

#Question id: 7015

#Unit 5. Developmental Biology

During the specification of neural crest cells, the neural plate is bordered by neural crest anteriorly and caudally, and by placodal ectoderm anteriorly. If the ectodermal cells receive both BMP and Wnt for an extended period of time, they become