TLS Online TPP Program

#Question id: 7105


The "default model" for neural tissue formation states that

#Unit 5. Developmental Biology
  1. No mechanism is required to form nervous tissue in the embryo; it forms unless signals direct development of epidermal tissue.
  2. Neural tissue formation is the default state, such that special induction is required to form mesoderm, endoderm and epidermis, but not neurectoderm.
  3. Neurectoderm formation is inhibited by the BMP proteins present throughout the early embryo, and this inhibition is relieved by BMP antagonists from the organizer, such as chordin
  4. The induction of neural tissue is the default state in embryos, and all other inductions are special.
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TLS Online TPP Program

#Question id: 11544

#Unit 7. System Physiology – Animal

When a steroid hormone and a polypeptide hormone exert similar effects on a population of target cells, then ________.

TLS Online TPP Program

#Question id: 11545

#Unit 7. System Physiology – Animal

Growth factors are local regulators that ________.

TLS Online TPP Program

#Question id: 11546

#Unit 7. System Physiology – Animal

Steroid and polypeptide hormones typically have in common ________.

TLS Online TPP Program

#Question id: 11547

#Unit 7. System Physiology – Animal

A cluster of tumor cells that produces and secretes growth factors to induce surrounding cells to grow and divide is showing which type of cell-to-cell signaling?

TLS Online TPP Program

#Question id: 11548

#Unit 7. System Physiology – Animal

If a portion of the pancreas is surgically removed from a rat and the rat subsequently loses its appetite, one explanation is that the removed portion contains cells that secrete a chemical signal that somehow stimulates appetite. Given this scenario, what type of chemical signaling is occurring?

TLS Online TPP Program

#Question id: 11549

#Unit 7. System Physiology – Animal

If a biochemist discovers a new molecule, which of the following pieces of data would allow her to draw the conclusion that the molecule is a steroid hormone?

I) The molecule is lipid soluble.

II) The molecule is derived from a series of steps beginning with cholesterol.

III) The molecule acts at a target tissue some distance from where it is produced.

IV) The molecule uses a transport protein when in an aqueous solution such as blood.