The history of life on Earth began about 3.8 billion years agohumans have been around for a mere 0.004% of the Earth's history
Answer:
Option 2, Arousal
Explanation:
Reticular activating system (RAS) or the ascending arousal system consists of nuclei and tracts and is involved in the regulation of wakefulness, sleep aspects and arousal.
RAS is located in the mesopons and interacts with the basal forebrainand thalamocortical systems. It activates the cerebral cortex and thereby maintain the consiusness. The neurons located at the pontomesencephalic junctionparticipates in this activity of arousal.
Hence, option 2 is correct
Answer:
B) missense mutation
Explanation:
A type of base substitution that results in the replacement of one amino acid by another is called missense mutation. Missense mutations affect the mutated proteins in several ways. It may alter the amino acid composition of the active site of enzymes and render the enzymes inactive.
The wild type polypeptide chain has the following sequence of amino acids: Met-Ala-Gln-Arg-Glu-Leu. The mutated polypeptide has glycine in place of arginine. The rest of the amino acids are the same in wild type and mutated protein. This means that the mutation changed the genetic code of arginine into the genetic code of glycine resulting in the incorporation of glycine in position 4. This is an example of a missense mutation.
If she is O+ then others of O+ and O- can donate to her. If she is O- then only those with O- can give blood to her.
Answer:
A sucessão primária ocorre em ambientes estéreis, onde não havia vestígios de organismos vivos que a ocupassem antes. Esse ambiente pode ser um local vulcânico em que a lava derretida destruiu o meio ambiente ou foi causada por dunas. A comunidade inicial de organismos para habitar esses ambientes é conhecida como sucessores primários ou colonizadores primáriosrimários
Explanation:
Primary colonisers initiate primary succession as such they are important to the future of such environments. They are though breeds of organisms that make use of scarce resources to survive in harsh environments. Without their ability to survive, there will be little or no way other forms of succession can take place. Reasons, why they may not persist, maybe too much stress imposed on them by the environment and above all their inability to compete when other successors come on board.
