D. A deceased family member
Answer:
Phagocytic defense in the normal lung is shared principally by two kinds of cells - alveolar macrophages that reside on the air surface and roam the alveoli and PMNs that circulate in the intravascular space or are stored transiently in areas adjacent to the capillary-alveolar interface (marginated in capillaries)
Explanation:
mark brainliest pls
Answer:
The question is incomplete.
However, I notice that your question is mainly dealing with
"Nucleotides with a single ring structure"
I tackled that part, also providing explanation to the point you focused on.
Explanation:
Nucleotides are compounds in which nitrogenous bases (purines and pyrimidines) are conjugated to the pentose sugars (ribose or deoxyribose) and at least one phosphate group. Thus a nucleotide consists of a nitrogenous base, pentose sugar and at least one phosphate group.
Examples of the nitrogenous bases are Adenine, Guanine, Thymine, Uracil and Cytosine. Of all, Thymine, Uracil and Cytosine are with single ring, while Adenine and Guanine are double ring structure.
A embryo is the unborn child from when they were conceived to 10 weeks and fetus is the unborn child from 11 weeks till birth
A water molecule consists of two atoms of hydrogen linked by covalent bonds to the same atom of oxygen. Atoms of oxygen are electronegative and attract the shared electrons in their covalent bonds.