After the macrophage fails the Helper T Cell stimulates the B cells if pathogen is extracellular and Cytotoxic T Cells if the pathogen is intracellular. Once the pathogen is killed the B Cells create Memory B Cells and the Killer T Cells create memory T Cells.
Answer:
In biology, a molecular clock can be described as a method to determine the time for the divergence of species which occurred by the process of evolution.
Explanation:
The mutation rates of different molecules are used in this method. The mutation rates for DNA sequences and amino acid sequences are usually considered. The molecular clock can be used to compare and estimate the splitting of a lineage. For example, by this method, one can interpret when the chimpanzees and humans diverged from each other.
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-Toshino
Answer:
This is because there is no air in space – it is a vacuum. Sound waves cannot travel through a vacuum. ... Even the emptiest parts of space contain at least a few hundred atoms or molecules per cubic metre. Space is also filled with many forms of radiation that are dangerous to astronauts.
Answer:
e) unicellular, colonial, or multicellular.
Explanation:
Protists originates from the Kingdom Protoctista. They comprise of organisms that are unicellular (Amoeba) or unicellular-colonial (volvox) in nature and which have no tisssues, therefore they are at the cellular level of organization.
Examples include, Amoeba, Paramecium, Euglena, Slime mold, Kelp, Diatoms, DInoflagellates. etc.
Some of them are also considered to be multicellular eukaryotes e.g slime molds, red algae etc. Eukaryotic organisms are organisms that possess cells containing a nucleus.
Characteristics in which protists exhibit varies from one species to the other.
For example, the mode of nutrition in eukaryotic algae are autotrophic in nature, in amoeba, they are gifted with pseudopods(false feets) in which they used to engulf prey(a term known as phagocytosis) therefore making them to be heterotrophic in nature.
In protist, locomotion varies from one organism to another. For example, in Amoeba , locomotion is achieved by extending and retracting pseudopods, Euglena are flagellated in nature , hence they move with the flagella. In Paramecium that are ciliated in nature, they move by propelling their cilia. etc.
The answer is A) air temperature.
