<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.
it has an alternating chemical<span> phosphate and </span>sugar<span> backbone, making the 'sides' of the ladder. (Deoxyribose is the name of the </span>sugar<span> found in the backbone of DNA.) In between the two sides of this </span>sugar<span>-phosphate backbone are four nitrogenous bases: adenine (A), thymine (T), </span>cytosine<span> (C), and guanine (G).</span>
I would say it is true and if it isn’t then I’m sorry.
Answer:
1. Vestigial organs.
2. Homologous structures.
3. Analogous structures.
Answer: Stored potential energy
Explanation: