Answer:
A <u><em>receptor</em></u> is a protein that recognizes and responds to a signal.
Explanation:
A receptor is a protein molecule present on the cells on which the signalling molecules can bind and generate a physiological response. Some receptor molecules can also respond to Sun and light. Each type of cell has specific receptors molecules and hence can respond to specific signals. The receptor molecules hence tend to receive signals for a cell. Molecules such as hormones bind to the receptors.
-Homologous structures in different organisms
Correct answer: B). The phagocytotic barrier, which is a part of innate immunity
The scenario represents the phagocytosis, which is a type of endocytosis by which the cell engulfs microbial pathogens. The main cells of the immune system that are involved in phagocytosis include macrophages, neutrophils, and dendric cells.
It is a mechanism which is used by the immune system to kill and processing of antigen that play an important role in innate immune response.
Hence, the correct answer would be option B.
The answer to that is False.
The oldest true fossils are trace fossils called Stromatolites found in Australia, and dated between 3.5 to 3.3 billion years old.
Raphael Baumgartner and their team have finally uncovered evidence of organic matter in the ancient rock formations known as stromatolites found at the Dresser Formation fossil site in the Pilbara region of Western Australia. They detail their findings in a new article published in the journal Geology.
With a variety of methods, including scanning electron microscopy, scanning transmission electron microscopy, energy dispersive X-ray spectroscopy, Raman spectroscopy, nano-scale secondary ion mass spectrometry, and stable carbon isotope analysis, the researchers examined the samples in thin slices.
According to the team's analyses, pyrite, a mineral with many tiny pores, makes up the majority of the stromatolites. Additionally, the pyrite contains nitrogen-bearing organic material and strands and filaments of organic material that closely resemble the remains of microbial biofilm colonies.
To know more about stromatolites click here
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