Answer:
C. 2 and 4 are correct
Explanation:
Institutional review board protects the rights of human research.
They are involved with reviewing of all research that involves the use of humans before it is conducted and protect the welfare of the human involve and the privacy.
The member of the board must be 5 and above and it include people from different fields that are knowledgeable and will provide findings on human research. A non scientist is also involve and someone from other field.
2 and 4 is correct
<span>A cross-sectional study examines all of the participants at one time. So for a cross-sectional study of cancer survivors, we would gather some sample of former patients and find out how long they have been in remission.
The problem with that cross-sectional design is we would be missing the people whose cancer had returned and caused them to die before our experiment started; we would have introduced a problem called "survivor bias" by only counting people who were STILL in remission and still alive.
A better experiment will use a longitudinal design of enrolling people whose cancer has just gone into remission, and following them to see how long they stay healthy.</span>
Answer:
The statement that best describes process of succession after a forest fire is A. Small plants grow but are eventually replaced by larger plants.
Explanation:
The example illustrated in this question is a kind of secondary succession.
Succession can be described as the variations in a particular community or ecosystem over a period of time. Succession has two types which are
- primary succession
- secondary succession
Secondary succession results due to natural disturbances like fire, storms, etc.
In this kind of succession, a natural disaster completely destroys a community leaving behind only barren soil. Over a period of time, Small plants start to grow on this land. Herbaceous plants are the first ones to evolve. Eventually, the larger plants start to grow later and the land becomes revived again.
The number indicates the mass number of the atoms of the element. 15N, therefore, is heavier than 14N. Mass number is the total number of protons and neutrons in the nucleus of the atom. While 14N has 7 protons and 7 neutrons, 15N has 7 protons and 8 neutrons.
