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.
Answer:
Radiation
Explanation:
Reflection and absorbtion by the atmosphere prevent some <u>radiation</u> from reaching Earth's surface.
Protein is assembled inside cells by an organelle called a ribosome. Ribosomes are found in every major cell type and are the site of protein synthesis.
