1. natural selection acts on existing traits because you can not evolve into something you didn't have
2. original structures evolve to accomplish new function in order to survive
A batsman is unlikely to score a century in every cricket match. This is an example of "partial reinforcement".
<u>Option: C</u>
<u>Explanation:</u>
Unlike constant reinforcement, partial reinforcement is only strengthened during certain times or time ratios, rather than emphasizing the action every single time. This method of arranging reinforcement is also called intermittent reinforcement after certain number of correct answers or certain interval of time. Thus here a batsman donot plan intentionally to make a century in every cricket match, but it goes random. Although when they need to score high on pressure, they force themselves to stretch as much possible which is not general.
Answer:
G1 - S - G2 (may be is option D)
Explanation:
The interface begins with phase G1 where the cell increases its volume and the mass is doubled.
Then, we continue with the S phase where DNA and histones are synthesized.
Afterwardsy we reach the G2 phase where the chromosomes are duplicated.
Finally we reach, the begining of mitosis.
Answer:
The correct answer is- photosynthesis
Explanation:
According to the endosymbiotic theory, an ancestral cell engulfed a cyanobacteria and lived in symbiotic association with that bacteria and over time this bacteria evolved into the chloroplast and the ancestral cell developed into plant cell.
So as cyanobacteria was the first aerobic cell that can evolve oxygen and can do photosynthesis to produce organic food so it could be concluded that the presence of endosymbiotic cyanobacteria provided a cell with the advantage of photosynthesis.
