C. testable and observable
Answer:
They should think of an alternative explanation for their results.
Explanation:
The next step that the scientists should take is to interpret why their hypothesis went wrong. The researchers should look for patterns in their observations and provide an alternative explanation for the results which occurred. Based on the results and their understandings, they should further make another hypothesis and check for its authenticity.
In scientific researches, the results of a hypothesis generally do not get the expected results but this leads to new findings and discoveries.
B- roots and steams that can store a lot of water
<u>Answer:</u>
Recent evidence suggest that feathers evolved from scales and suggest that 'feathers and pycnofibers' could be homologous.
<u>Explanation:</u>
- One of the major difficult issue related to bird evolution is the evolution of feathers.
- Feathers are considered as the most 'complex integumentary structures' which are found in vertebrates.
- Evolutionary developmental biology suggests that the 'planar scale structure' is been modified for developing into feathers by 'splitting' to form web like structures.
- Scales and Feathers consist of 'two distinct form of keratin' so it was thought that 'each type was exclusive skin structure' but recent study suggests that they are developmental expressions of same skin structures.