Answer No 1:
The correct option is c) Both mitochondria and chloroplast contain DNA that is different from the nucleus.
Explanation:
The theory of endosymbiosis proposes that all the eukaryotic organisms have arisen from prokaryotes. This theory proposes that organelles such as DNA and nucleus were once prokaryotic cells. These smaller prokaryotic cells were engulfed by the larger prokaryotes which gave rise to eukaryotes eventually. These organelles possess their own DNA which is different from the DNA of the nucleus.
Answer No 2:
The correct option is C) aerobic organisms
Explanation:
The scientists propose that the initial conditions of the Earth were not favourable for supporting aerobic life. Scientists propose that photosynthetic organisms like cyanobacteria released oxygen into the environment which made the life of aerobic organisms possible on Earth.
Answer No 3:
The correct option is A) It proved the theory of spontaneous generation.
Explanation:
Spontaneous generation can be described as the generation of life from non-living things. Some scientists proposed that living organisms are formed by non-living things.
When the concentration of a certain solute is low inside the cell with respect to the cell's external environment, then the cell performs active transport of the solute from the cytoplasm with a low concentration of solute within the cell to the cell's external with a high concentration of the solute. This process of active transport requires the need of energy in the form of ATP to drive the pumps that are present on its cell membrane.
It is reticulate venation, where the veins are arranged in a network.
Answer;
-Distal end
Explanation;
-The part of the esophagus that is farthest from its beginning at the throat is the distal end.
-The esophagus is a muscular tube connecting the throat with the stomach. It is about 8 inches long, and is lined by moist pink tissue called mucosa.
-Both ends of the esophagus are closed off by muscular constrictions known as sphincters; at the anterior, or upper, end is the upper esophageal sphincter, and at the distal, or lower, end is the lower esophageal sphincter.
