<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: B. Osmosis Across a Membrane
The movement of water across a gradient is called osmosis.
<span>This person is experiencing common physical symptoms of what is called "withdrawals". Opiates, when used illegally, can be highly addictive. This drug targets the central nervous system (the brain, cardiovascular and respiratory systems) and contains opioid receptors that receive opiate drugs. Abusing this drug can disrupt a person's brain chemistry, leading to severe physical withdrawal symptoms as listed in the question.</span>
Answer:he needs a lot rest,less thinking or worry
Explanation:
Due his physical appearance,his blood pressure is high and pale skin, it's obvious that he is stressed out
