Answer:
OPTION A is the correct answer
If the image contains life forms and living things, then it is the biosphere.
If the image contains frozen water bodies, such as the arctic tundra, it is the cryosphere.
If the image contains soil and other solid abiotic components of the Earth, then it is the geosphere.
If the image contains water in the liquid form, then it is the hydrosphere.
Answer:
D. Cell signalling which is released by one type of cell and acts upon a different cell
Explanation:
According to this question, adrenal cells near the kidney releases an hormone called ADRENALINE, which causes the cells of the heart to beat faster. This is an example of CELL SIGNALLING because chemical signals released by adrenal glands causes/triggers a response in the heart cells.
The chemical signal released by the adrenal cells is the ADRENALINE HORMONE, which induces a response in cells that are different from the cells of release (adrenal cells).
Answer:
Constitutive activation is the alteration of a protein or signaling pathway such that it is functional or engaged even in the absence of an upstream activating event. For example, RasD is constitutively active because it cannot bind GAP and therefore remains in the GTP-bound, active state even when cells are not stimulated by growth factor to activate a receptor tyrosine kinase.
Constitutively active Ras is cancer promoting because cells will proliferate in the absence of growth factors, and thus normal regulatory mechanisms for cell proliferation are bypassed.
(a) A mutation that resulted in Smad3 binding Smad4, entering the nucleus, and activating transcription independent of phosphorylation by the TGFβ receptor would render Smad3 constitutively active.
(b) A mutation that made MAPK active as a kinase and able to enter the nucleus without being phosphorylated by MEK would render MAPK constitutively active.
(c) A mutation that prevented NF-KB from binding to IK-B or that allowed NF-KB to enter the nucleus and regulate transcription even when bound to IK-B would render NF-KB constitutively active.
