<span>Cytotoxic t-cell subpopulations are specialized to combat intracellular pathogens, whereas helper t-cell subpopulations are specialized to combat extracellular pathogens.
</span>Cytotoxic t-cell are CD8+ cells. Cytotoxic t-cell uses granzymes to <span>kill </span><span>intracellular bacteria, that lives in the cytosol such as viruses. They identify the pathogen forgein peptids that are bounded to MHC-I on the cell surface.
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cd4+ T helper (Th) cells include Th1, Th2, and Th17 cells. They contribute to aliergic reactions and fighting extracellular parasites.
For a introduced species to be invasive species, there needs to be certain characteristics of the species.
<h3><u>Explanation</u>:</h3>
Invasive species are the species that belong to some other place and are introduced to a new place by means of any human interference. But many species are often transferred from one place to another. But not all of them remain there as an invasive species. This is because for being an invasive species, they need to have certain characteristics:
A. They need to have high rate of reproduction.
B. They need to have short dormancy periods.
C. They need to have high generic variability.
D. They need to be polyphagous and gregarious.
E. They need to have high dispersal rate and great adaptability.
F. They need to have phenotypic plasticity.
<span>crushing a can.
melting an ice cube.
boiling water.
mixing sand and water.
breaking a glass.dissolving sugar and water
.shredding paper.
<span>chopping wood.</span></span>
There are several mutations that benefit the organism.A well known example is the antibiotic resistance developed by bacteria, which aid in their survival even when they are exposed to a given antibiotic. A single gene mutation in wild almond trees resulted in a variety that no longer synthesizes amygdalin.
Answer:
Option D
Explanation:
When amniotic sac breaks and its internal fluid spilled then there are high chances that the fluid may enter into the throat of the infant and may block his/her air passage way. Therefore, in such situation a standard solution is formulated which requires the doctors to suction the air passageway of infant and restrict it from getting choked and contaminated with meconium. A valve mask is primarily used before suctioning
Hence, option D is correct
