The littoral zone<span> is the part of a sea, lake or river that is close to the shore. In coastal environments the littoral zone extends from the </span>high water mark<span>, which is rarely inundated, to shoreline areas that are permanently submerged. It always includes this </span>intertidal zone<span> and is often used to mean the same as the intertidal zone. However, the meaning of "littoral zone" can extend well beyond the intertidal zone and that is you answer</span>
The correct answer is d. 3.5 billion years.
Prokaryotes were the first forms of life on Earth long before simple multicellular life appeared because of their ability to withstand extreme conditions. It is believed that the first living forms were bacteria combined with archaea in the microbial mat (multi-layered sheet).
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Kinase-connected receptors or receptor tyro-sine kinases react for the most part to protein and chemical go between. A solitary trans membrane helix interfaces the extracellular restricting area to the intra-cellular space. e.g. insulin, development factors. The official of the ligand triggers the commencement of a few succession of occasions related with phosphorylation of proteins, this is called protein kinase course.
For instance, the official of development hormone to the receptor in the plasma layer causes dimerization (by the actuation of Janus kinase 2, JAK2) of the receptor (conformation change) that bring about auto-phosphorylation of tyro-sine buildups. The official of SH2-space (src homology) protein (Grb-2) to the phosphorylated tyro-sine buildups invigorates cell development through a course of protein phosphorylation.
a). RTKs are the trans-membrane receptors, which have a ligand restricting site on the extracellular area and tyro-sine authoritative on the intra-cellular space. In the event that it comes up short on the extracellular area, the ligand can't tie to the receptor site, so no cell reaction happens.
b). On the off chance that it does not have the intra-cellular space, the ligand can tie to the receptor site, the receptor can't impart signs tot eh intra-cellular area because of the absence of intra-cellular space.
Answer:
In a pinhole camera, light passes through the pinhole to project an upside-down image onto the back of the box, and in the human eye, light passes through the lens to project an upside-down image on the back of the retina
<span>The stage at which all the cells show crossover chromosomes is meiotic prophase I. The crossover is the exchange of genetic material between homologous chromosomes. Homologous chromosomes are present in the meiosis I. Regarding the phase of meiosis I, it is expected that the crossover takes place in meiotic prophase I since homologous chromosomes pair up in the prophase.</span>