Answer:
What is the effect of power/magnification on the frequency and size of organelles under a microscope?
Explanation:
Organelles within the cell are responsible for carrying out various functions. Some cells are more specialized than others, and may have particular organelles at a higher frequency, or showing a variation in size; sub-cellular structures become more visible at higher magnifications under the microscope.
Hypotheses:
- organelle A's frequency decreases while B's frequency increases at higher magnifications
- organelle A's size increases while B's size decreases at higher magnifications
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<em>Dependent variables: size and frequency cell organelles</em>
<em>Independent variable: power/magnification at low (x4), medium(x10) and high (x40)</em>
<em>Controlled variables: Type of organelles, microscope used, cell examined, </em>
Method:
1. Examine the organelles A and B in a cell mounted on a slide; use the fine adjustment to focus on the cell.
- Frequency: What is the average number of organelle A versus B, seen at low (x4), medium (x10) and high (x40) magnifications?
- Size: Measure the average diameter of organelle A versus B using an ocular micrometer at low, medium and high magnification.
2. Record and tabulate observations.
Answer:
Their nephron loop is closely wrapped with vasa recta.
Explanation:
Cortical nephrons are located in the cortex.
They form 85% of all the nephrons in the kidney. They are located mostly within superficial cortex of kidney. The loop of henle of a cortical nephron is relatively short and hence not closely wrapped with vasa recta. Efferent arteriole delivers blood to a network of peritubular capillaries.
Cancer is uncontrolled cell division.
Answer:
The notion of maximum parsimony does not consider the entire evolutionary history, being able to suppress important evolutionary points that would cause errors in the evolutionary relationship of a species.
Explanation:
Maximum parsimony is a criterion for optimizing phylogenetic trees. This is because through this criterion an analysis is made of all possible phylogenetic trees of a species, observing which one is smaller and offers simpler and summary information. On the one hand, the study of the smallest phylogenetic tree can be faster and more understandable, since its information is basic and direct. However, maximum parsimony can lead to errors in the establishment of an evolutionary relationship of a species, because it suppresses the entire history of evolution of that species, being able to suppress really important points in one of the clades, which would result in an incorrect evolutionary conclusion.
23. The answer would be the third option.
24. The answer would be the second option.