The taiga biome is the largest terrestrial biome and extends across Europe, North America, and Asia. It is located right below the tundra biome. The taiga biome is also known as coniferous forest or boreal forest. This biome typically has short, wet summers and long, cold winters. Precipitation is moderate in the taiga. It gets plenty of snow during the winter and plenty of rainfall during the summer.<span>Interesting Taiga Biome Facts:Fires are very common in the taiga biome. These fires are necessary to help rid the area of old and sick trees.There is not much variety in plants. Majority of the plants are conifer trees which is why the taiga is referred to as the coniferous forest.The conifer trees in the taiga biome are referred to as evergreen. This means they remain green all year round and never drop their leaves.<span>Because evergreen trees do not drop leaves, there is nothing to keep the soil in the taiga full of nutrients. This is the reason why there is not much variety in the vegetation. </span>Softwood timber is used to make paper. Majority of softwood timber comes from the taiga biome.<span>Although two major cities, Toronto and Moscow, are located in the taiga biome, most of this biome is uninhabited by people. </span>The taiga biome is very cold during the winter. Temperatures can reach as low as -60° F.For six months out of the year, the temperature in the taiga biome is below freezing.Plants can only grow during the summer when temperatures are favorable. This growing season only lasts about three months.Many animals of the taiga biome have to migrate to warmer areas or hibernate during the long, cold winters.Animals of the taiga have many specialized adaptions including lots of thick fur or feathers and the ability to change colors during different seasons.Scientists believe that the taiga biome was completely covered by glaciers many years ago.The taiga forests are endangered due to logging and mining by humans. When trees are cut down in the taiga, it takes a very long time to restore itself because of the very short growing season.Although there are not many animals in the taiga biome, it inhabits millions of insects. Birds migrate there to feed off these insects every year.<span>The temperature change in the taiga is extreme. It is either summer (hot) or winter (cold). The spring and fall are too short to notice.</span></span>
Answer: zap70, ITAM.
Explanation:
An antigen is any substance that is capable of stimulating an immune response by activating lymphocytes, which are the body’s infection-fighting white blood cells. Examples of antigens could be proteins that are part of bacteria or viruses or components of serum and red blood cells from other individuals, all of them are foreign antigens originated outside the body. However, there can also be autoantigens (which are self-antigens), originated within the body. In normal conditions, the body is able to distinguish self from nonself. <u>And the antigens that represent a danger induces an immune response by stimulating the lymphocytes to produce antibody or to attack the antigen directly</u>. This is called an antigenic stimulation of the immune system.
ZAP-70 (Zeta-chain-associated protein kinase 70) is a protein that is part of the T cell receptor, thereby it plays a critical role in T-cell signaling. When the TCR (receptor of T cells) is activated by the presentation of the specific antigen through the MHC, a protein called Lck acts to phosphorylate the intracellular CD3 chains and the ζ chains of the TCR complex, allowing the binding of the cytoplasmic tyrosine kinase, ZAP-70. Lck then phosphorylates and activates ZAP-70, which in turn phosphorylates another molecule in the signaling cascade called LAT (short for Linker of Activated T cells), a transmembrane protein that serves as an anchor site for several other proteins. The tyrosine phosphorylation cascade initiated by the Lck culminates in the intracellular mobilization of calcium ion (Ca2+) <u>and the activation of important signaling cascades within the lymphocytes.</u> These include the Ras-MEK-ERK pathway, which is based on activating certain transcription factors such as NFAT, NFκB and AP-1. These transcription factors regulate the production of of certain gene products, most notably cytokines such as interleukin-2 that promote the long-term proliferation and differentiation of activated lymphocytes.
The ITAM motifs (immunoreceptor tyrosine-based activation motif) are sequences of four amino acids present in the intracellular tails of certain proteins that serve as receptors within the immune system. Thus, <u>some receptors such as the TCR have ITAM sequences that, when activated, trigger an intracellular reaction based on consecutive phosphorylations</u>. Kinases are recruited for this purpose.
So, ZAP-70 is a protein tyrosine kinase with a role in T-cell receptor signal transduction. During T-cell activation, ZAP-70 binds to ITAM and becomes tyrosine phosphorylated. The binding of ZAP-70 to the phosphorylated ITAM is able to activate its kinase activity, <u>and relieves the inhibition of the transcription factor which regulates genes that are involved in the immune reaction</u>.
Lava<span> is molten rock. It is </span>created<span> deep beneath Earth's surface (often 100 miles or more underground), where temperatures get hot enough to melt rock. Scientists call this molten rock magma when it's underground.</span>Lava<span> is molten rock.
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Answer:
The correct option is C: antigen-binding sites
Explanation:
The antibody is shaped much like the letter Y in the English alphabet. It has two antigen binding sites that are identical in nature. The specificity of these sites is determined by the amino acid sequence that makes it up. Antibodies are complementary to these antigen binding sites, and the antibodies have an incredible ability to recognize a great variety of antigens.
Hope that answers the question, have a great day!
