<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.
Answer:
He examined covered and uncovered meat to determine that maggots came from eggs.
Explanation:
Prior to Redi's experiment and other supporting experiments, it was formerly believed that life could emanate from non-living things, for example, the generation of maggots from rotting meat.
In 1668, a scientist called Francesco Redi disproved the idea of spontaneous generation. He did this when he experimented that the maggots from meats are only as a result of eggs laid by flies when they perched on the meat.
He placed the meat in two jars; an uncovered jar and another in a covered jar with a cloth, after several days, the uncovered jar had maggots on the meat, while the covered jar had no maggot on the meat, but on the cloth. With this experiment, he was able to demonstrate that the maggot arose from the eggs of the flies, not the meat itself which is nonliving and hence, disproved the idea of spontaneous generation.
The Krebs cycle<span> occurs right after glycolysis. The substance that begins the </span>Krebs cycle<span> is a 3-carbon molecule called pyruvic </span>acid<span>. The process breaks down the pyruvic </span>acid<span> into acetyl coenzyme A, releasing one of the carbon atoms into carbon dioxide.
hope it help</span>
The Answer is C, hope this helps!
