Answer:
The stages of most stars life in order are: A Protostar, Main Sequence, Red Giant B Protostar, Main Sequence, Red Dwarf C Main Sequence, Red Dwarf, Protostar D Red Giant, Main Sequence, Protostar E Nebula, Protostar, Red Dwarf. 2 What does a protostar have to do to become a star? A Nuclear fusion in its core. B Nuclear fission in its core.
The overall mechanism of cellular respiration<span> involves four subdivisions: glycolysis, in which glucose molecules are broken down to form pyruvic acid molecules; the Krebs cycle, in which pyruvic acid is further broken down and the energy in its molecule is used to form high-energy compounds such as NADH.
Source: </span><span>Cellular Respiration - Cliffs Notes</span>
Because an amino acid<span> cannot be </span><span>synthesized</span><span> by the organism, and it must be supplied in its diet.</span>
<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.
Endocytosis even though there are two types of this