A characteristics that helps an organism to survive and reproduce is the best description of an adaptation.
Option D
<u>Explanation</u>:
Adaptation is simply defined as the evolutionary process of the organism when they feel comfortable to their natural place of existence. The process takes place in many generation to generation and it is passed on with genetic inheritance. With its biological phenomena it explains a trait in organisms which helps animal to survive and reproduce. It is also process of changing to different places for the organisms. Adaptation happens through mutation or natural selection.
Answer:
Mitochondria and chloroplasts are much larger than prokaryotic cells.
Explanation:
According to the Endosymbiotic theory, all the components of eukaryotic cells were once individual prokaryotic cells which were able to function on their own.
The mitochondria was independent enough to perform aerobic respiration and produce energy and the chloroplasts were able to independently convert the energy from the Sun to the chemical energy through the process of photosynthesis.
Later, these cells were engulfed by a single cell and these prokaryotes combined to form a eukaryote that was capable of performing all the functions that the independent cells could.
So, the mitochondria and chloroplasts were able to reproduce on their own, had their own ribosomes and had DNA resembling that of bacteria as they were prokaryotic in nature.
However, mitochondria and chloroplasts could not be larger than the prokaryotic cells to support the endosymbiotic theory.
This is because in order to establish a relationship between the bacteria and the mitochondria and chloroplasts, and for these organelles to have developed from bacteria as their ancestors, they must have sizes comparable to bacteria and other prokaryotes.
At the same time, size in itself is not enough evidence to support origin of these organelles from the bacteria.
<span>Chloryphyll is the main chemical used in photosynthesis.
</span>
Answer:
The above paragraphs describes that how salt- and fresh-water fish regulates their osmoregulation. Hence, the correct answer would be c. have adapted to deal with osmosis.
Osmosis is the process by which solvent's molecule move from region of low concentration (hypo-tonic) to the region of high concentration (hyper-tonic) through a semi-permeable membrane.
In sea-water fishes, the body fluids are hypo-tonic to the surrounding water and thus water is kept moving out of their gills. In order to prevent the excess water loss they need to drink water constantly and excrete concentrated urine.
In contrast, fresh-water fishes body fluids are hyper-tonic to surrounding water and hence, water keeps entering in their body through gills. So, in order to prevent excess dilution they absorb salt from surrounding with the help of gills and also their bodies reabsorb salt from urine.
