Answer:
C. Antibodies directly destroy antigen-bearing invaders by releasing potent toxins.
Explanation:
An antibody is part of the host cell defense and it’s made by B-cells (white blood cell). The structure of the antibody consists of two light chains and two heavy chains, and at the very tip of the antibody is a hyper variable region, which is the antigen binding site that recognizes lots of different types of antigens. An antigen is anything that is foreign to the human body (the body does not recognize it as self), it can be a virus, bacteria, fungi, some foods and particles like dust that cause allergies and in some cases your own body will appear as foreign.
Antibodies act like small keys looking for the perfect lock, once they find their target they alert the immune system to mount a full immune response. Using this binding mechanism, an antibody can tag a microbe or an infected cell for attack by the immune system or it can neutralize its target directly for example, by blocking a part of a microbe needed for entering and invading a cell. Depending on the antigen the antibody binding may impede the biological process causing the disease or may activate macrophages to destroy the foreign substance, it does not release potent toxins. Antibody binding can cause the clumping (agglutination) of large particles (viruses, bacteria etc.) making it a large complex, making phagocytosis more efficient (as they eliminate lots of clumped up viruses or bacteria in one go, and not one by one).
Answer:
Sand is an example of a mineral.
Ans.
The codons show genetic codes, made up of triplet of nucleotides in DNA or RNA that code for specific amino acids. The different codes can code for a same a amino acid. When a substitutional mutation occurs in genetic material, it shows substitution of one nucleotide pair for another and leads to formation of a different codon.
The first mutation that leads to CAU to CAC, it will not show any potential damage as both CAU and CAC codons code for histidine amino acid.
The second mutation that leads to UGU to UGC will also not show any damage to protein as both of these codons code for cysteine amino acid.
The third codon, that results UCU to UUU will cause a potential damage to protein as UUU codes for phenyl alanine (an aromatic, non-polar amino acid) and UCU codes for serine (a polar amino acid).
Thus, the correct answer is 'option C).' as in a protein, substitution of serine with phenylalanine will lead to change in structure and function of that protein.
All cells have all these except chloroplast and cell wall
Answer:
B
Explanation:making things with light”. Photosynthesis takes place inside capsules in the leaf cells, called CHLOROPLASTS.
