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2 years ago

Rb is an important protein for controlling cell proliferation by blocking entry into S phase. How does it exert its effect?

Biology

1 answer:

amid [387]2 years ago

5 0

Answer:

The main function of the RB protein is to inhibit the transition from the G1 to S phase. Its activity depends on its phosphorylation state: if RB is not phosphorylated (active state), it is bound to the transcription factor E2F, preventing its translocation to the nucleus and the activation of genes necessary for DNA synthesis; and if it is phosphorylated, by cyclin-CDK complexes, E2F is released and cell proliferation occurs.

Explanation:

Retinoblastoma (Rb) was the first tumor suppressor described and, as we know today, mutations in its structure determine a large number of cancers. Structurally, we speak of a large and multifunctional protein; which is organized in different domains. The activity of this protein is regulated, mainly, by phosphorylation at multiple sites described over the years and is involved in control mechanisms of the cell cycle, apoptosis and senescence.

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One adaption to life in flowing water is what?

Alla [95]

Answer:

Explanation:

There are many options, here are a few choices:

Fast moving water tends to be colder than slow water; some of it originates as snow melt on the sides of mountains, for example. For this, animals in fast water tend to be more cold resistant. This is why you do not see fish like freshwater trout in equatorial regions. These animals struggle and die in slow, warm water.

Fast moving water means that if the animal or plant wants to stay put, it must resist the flow. Fish tend to be far more muscular and lean in these places, while insects like stoneflies, mayflies, and other larvae have ways to secure themselves to rocks and plants while growing. Plants develop strong root systems, and algae hold fast in rocky crevices in the river. Some animals also have suction in order to stay in place where there is fast flowing water.

Some animals have to adapt their reproductive systems as well. Because finding a mate is difficult in the sweeping waters, breeding tends to happen all at one time. As an example, salmon have runs, where thousands of fish all swim upriver at once to breed, can dramatically alter the surrounding ecology of the river. Insects like mayflies have hatches, where hundreds of thousands of flies swarm into the air at once to breed and lay eggs.

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2 years ago

Which is the BEST example of technological design

Reil [10]

Hello there! do you have any choices? if so would you please add them.

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2 years ago

Which action would allow you to distinguish between transpiration and

Rufina [12.5K]

Answer: D

Explanation:

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3 years ago

Read 2 more answers

Identify each event as the result of mechanical weathering or chemical weathering.

kow [346]

<h3>The following events are identified as chemical weathering:</h3>

The minerals in a marble statue react with water to form acids and pores in the structure.
The rocks in a region are streaked orange after being exposed to repeated rains.

Reason:

When the weathering process occurs due to chemical reaction, then it is considered as chemical weathering.

In the first case, minerals of marble statue are reacting with water to cause weathering. In the second case, due to the acidificaion reaction, the change of the color has happened after exposure to the repeated rains.

<h3>The following events are identified as Mechanical weathering:</h3>

A piece of rock crumbles after being constantly thrashed by strong waves.

Industrial runoff forms cracks in a rocky structure in its path.

Reason:

When the rock is broken into simple pieces without any chemical reaction it is considered as mechanical weathering.

In the first cause, due to the abrasion caused by the strong waves, weathering has happened, in the second case industrial run off may be of varying temperature and thus may cause heating or cooling of the rock and causes weathering.

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3 years ago

Generation of clonal diversity occurs primarily during which phase of life

iris [78.8K]

Fetal.

Hope this helps!

-Payshence

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3 years ago