Answer:
The correct answer is a) It brings a transport liquid into close contact with all cells in the body.
Explanation:
The circulatory system helps in bringing the blood which is a transport liquid in close contact with the cells present in our body. This helps in gas exchange between cells and blood. The circulation of blood in the body occurs by the pumping of blood by the heart into arteries, veins, and capillaries.
This circulation of blood plays many other vital functions like transport of nutrients to the cells, transport of waste products from the cell to outside the body, transport of hormones, maintenance of body temperature, etc.
So all these processes become possible when transport liquid comes in contact with the cells. Therefore the right answer is a.
Answer:
Gap 2 (G2): During the gap between DNA synthesis and mitosis, the cell will continue to grow and produce new proteins. At the end of this gap is another control checkpoint (G2 Checkpoint) to determine if the cell can now proceed to enter M (mitosis) and divide.
Explanation:
Answer:
1. P120 is degraded in the 26S proteasome
2. The 26S proteasome has a major role in protein degradation and is critical for protein homeostasis
3. Cell cycle and DNA replication are cellular processes regulated by the Ras and NFkB pathways
Explanation:
The proliferation-associated nucleolar protein (p120) is a protein known to be expressed during the interphase of the cell cycle, specifically in G1 and early S phase, where any problem with DNA replication trigger a checkpoint, i.e., a molecular cascade of signaling events that suspend DNA replication until the problem is resolved. In mammalian cells, the 26S proteasome is responsible for catalyzing protein degradation of about 80% (or even more) of their proteins. The 26S proteasome acts to degrade rapidly misfolded and regulatory proteins involved in the cell cycle, thereby having a major role in protein homeostasis and in the control of cellular processes. It is for that reason that inhibitors that block 26S proteasome function have shown to be useful as therapeutic agents in diseases associated with the failure of protein degradation mechanisms (e.g., multiple myeloma). The NF-κB are highly conserved transcription factors capable of regulating different cellular processes including, among others, cellular growth, inflammatory responses and apoptosis. Moreover, the MAPK/ERK pathway is able to transduce different signals received on the cell surface to the nucleus. The MAPK/ERK pathway is activated when a singling molecule binds to a cell receptor which triggers a signaling cascade that ends when a transcription factor induces the expression of target genes, ultimately producing a response in the cell (for example, the progression through the cell cycle).
Answer:
Acid deposition-usually referred to simply as acid rain-actually includes two forms of pollution, wet and dry. ... In the wet type of acid deposition, these compounds combine with water vapor in the atmosphere to form highly corrosive sulfuric and nitric acids.
Explanation:
The accumulation of acids or acidic compounds on the surface of the Earth, in lakes or streams, or on objects or vegetation near the Earth's surface, as a result of their separation from the atmosphere. Acid deposition can harm the environment in a variety of ways, as by causing the acidification of lakes and streams, the leaching of minerals and other nutrients from soil, and the inhibition of nitrogen fixation and photosynthesis in plants.♦ The accumulation of acids that fall to the Earth dissolved in water is known as wet deposition. Wet deposition includes all forms of acid precipitation such as acid rain, snow, and fog.♦ The accumulation of acidic particles that settle out of the atmosphere or of acidic gases that are absorbed by plant tissues or other surfaces is known as dry deposition.
