D.......the others deal with muscles and tendons.
Answer:
I'm fine with the classes I have at the moment. I'd like to do in person learning since online is the least interactive activity I've done my whole life. The current work load is like a train crash it's just scattered all over the place so in other words it's a whole lot of work and not a whole of time. I want this because I know what I want and what I need to do to reach the goals I have set in place, not everyone can say that.
Answer:
D. Yes, two hydrogen bonds could form between thymine and cytosine.
Explanation:
A hydrogen bond (often informally abbreviated H -bond) is a primarily electrostatic force of attraction between a hydrogen (H) atom which is covalently bound to a more electronegative atom or group, particularly the second-row elements nitrogen (N), oxygen (O), or fluorine (F)—the hydrogen bond donor (Dn)—and another electronegative atom bearing a lone pair of electrons—the hydrogen bond acceptor (Ac).
The formation of stable hydrogen bonds depends on the distance between two strands, the size of the bases and geometry of each base. Stable pairings occur between guanine and cytosine and between adenine and thymine (or adenine and uracil in RNA).
One hydrogen bond could form between the C4 carbonyl group on thymine (a hydrogen bond acceptor) and the C4 amino group on cytosine (a hydrogen bond donor). Another hydrogen bond could form between N3 of thymine (a hydrogen bond donor) and the N3 of cytosine (a hydrogen bond acceptor). Note that the C2 carbonyl groups found on both bases are both hydrogen bond acceptors and therefore a hydrogen bond cannot be formed between them.
