Answer:
Since valence shells are mostly empty in nonmetal atoms, the atoms attract and hold any electrons they can in order to fill their valence shells.
Answer:
secrete cytotoxic substance which triggers apoptosis of target cell.
Explanation:
Cytotoxic T cells have cell surface receptor which recognizes the antigen present on the receptor of target cell. This interaction initiates the process of killing of target cell.
After interaction cytotoxic t cell release cytotoxic substance called granzyme and perforin. Granzyme triggers apoptosis through the activation of caspases or by making the release of cytochrome c and activation of the apoptosome.
Perforin make pores in the cell and its action is similar to complement membrane attack complex. Therefore cytotoxic substances are released by Tc cells which trigger apoptosis of target cell.
Answer:
1HydrogenH2HeliumHe3LithiumLi4BerylliumBe5BoronB6CarbonC7NitrogenN8OxygenO9FluorineF10NeonNe11SodiumNa12MagnesiumMg13AluminiumAl14SiliconSi15PhosphorusP16SulfurS17ChlorineCl18ArgonAr19PotassiumK20CalciumCa
Asexual reproduction involves the production of offspring without the need for a secondary partner to contribute genetic information.
Pollination and mating are two forms of sexual reproduction, so B, C, and D are incorrect. A, because the new potato grows directly from the old without the contribution of new genetic material, asexually reproduces.
