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.
Answer: According to the World Health Organization (WHO), 462 million people face health problems because of under-nutrition and another 1.9 billion people face health problems because of over-nutrition.
Explanation: 462 million adults are underweight around the world according to the World Health Organization (WHO) while 1.9 billion are overweight or obese. Undernutrition, includes 4 sub-forms: wasting, stunting, underweight, and deficiencies in vitamins and minerals. Wasting is low weight-for-height, stunting is low height-for-age and underweight is low weight-for-age. Overweight or obesity is when a person is too heavy for his or her height.
Answer:
hehe. no i have more things to do than make a passage on bullying. look it up!
The ease of speaking during exercise. The theory is, if it’s harder to talk, then you’re activity doing exercise at a higher intensity level.
