The two strands are held together by Hydrogen Bonds
<h2>Evolution of Earth</h2>
Explanation:
The events of earth history from oldest to new are as follows:
- Earliest evidence of life on Earth.
- Production of oxygen by photosynthetic organisms.
- Origin of Eukaryotic cell.
- appearance of first tetrapods on land.
Scientists assume that the Earth evolved about 4.6 billions years ago. However, the first evidence of life dates back to 3.7 billion years ago. It is assumed that the conditions of primitive Earth were such that it could not support life. However the inorganic compounds spontaneously reacted and gave rise to biological molecules such as amino acids, proteins lipids etc.In this way the first cells appeared as prokaryotes, photosynthetic prokaryotes began to produce oxygen and gradually new forms of life arose.
An important event in the history of Earth is cambrian explosion during which several forms of life arose and diversified to occupy various strata of Earth.
Answer:
D
Explanation:
"If any one bring an accusation of any crime before the elders, and does not prove what he has charged, he shall, if it be a capital offense charged, be put to death."
Answer:
Psychoneuroimmunology is the study of the interactions among behavioral, neural and endocrine, and immune processes. The brain communicates with the immune system through autonomic nervous system and neuroendocrine activity.
Explanation:
Answer:
The answer is B. 1 cell to many millions of cells.
Examples of unicellular organisms ( single-celled organisms ) are <em>Amoeba </em>and <em>Paramecium </em>and examples of multi-cellular organisms are Human beings, Animals and Birds.