"These" should be referring to Alkali Metals.
They include metals such as Lithium, Sodium, Potassium etc.
They're classified as Group I elements because they all have one outmost shell electrons. This is why these metals are so reactive because they only need to lose one electron in order to achieve the octet of electrons (or duplet for Lithium), which means complete outmost shell electrons (2 or the 1st shell, others are 8).
The reason why they're especially reactive to Halogens (Group VII) elements are that Halogens have 7 outmost shell electrons, which only needs one more electron in order to get to the octet of electrons. So, if an Alkali metal reacts with a Halogen, the metal would give one of their electrons to the Halogen, that way, both of the elements can have an octet of electrons (or duplet).
Answer:
Genetic code
Explanation:
Genetic code refers to the set of rules by which the information encoded in the genetic material is translated into the proteins. The genetic code is present on the genes in the form of triplets of nucleotides called codons which specifies the specific amino acid.
The codon system of the genetic code rules allows the 4 different nucleotides to form specific amino acids by the combination of the four different nucleotide in the triplets.
Thus, Genetic code is the correct answer.
answer is antibodies.
B cells are a type of lymphocytes and it is responsible for the immune system. B cells help to protect body by producing specific antibodies to fight against each antigen which are strangers to the body specially for viral infections.
I think i see what he means the answer is B.
but correct me if i'm wrong.