Answer: Abiotic factor for polar: Ice
Abiotic for desert: Sand
Biotic for polar: Polar bears
Biotic for desert: Cacti
The types of factors are different because there are different set conditions for each ecosystem. A cactus is built for it's hot, dry ecosystem. If it were to move to a polar ecosystem it would not survive there. Same for the polar bear. It's built for polar regions. It has white fur to blend with the white ice to help it blend in and it's adapted to swim to get it's food source.
Explanation:
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.
Each fossil with the layer where it will be present based on are layer A-BIRDS, layer B -dinosaurs , layer C-amphibians, layer D-Corals ,layer E -trilobites.
<h3>What is the oldest fossil layer?</h3>
The Pilbara area of western Australia's Strelley Pool is home to the oldest known fossils. Stromatolites are fossilized mats of microorganisms wedged between sedimentary layers. The fossils have an age of 3.4 billion years.
<h3>How are the layers containing the fossils organized?</h3>
The Law of Superposition, which asserts that in undisturbed rock sequences, the bottom layers are earlier than the top ones, is the foundation for this theory. Because of this, certain fossil discoveries can be dated using the strata—a particular stratum of rock—in which they were discovered.
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I think it's D. It shields life forms on the surface from radiation?
Answer:
squamous epithelium maybe
