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:
Membrane proteins can function as enzymes to speed up chemical reactions, act as receptors for specific molecules, or transport materials across the cell membrane. Carbohydrates, or sugars, are sometimes found attached to proteins or lipids on the outside of a cell membrane.
Without oxygen, life cannot be sustained as it is an essential reactant in the respiration process. So the evolution of photosynthesizing bacteria increased the amount of oxygen in the atmosphere through converting water and carbon dioxide into oxygen with the help of sunlight. This provides a suitable environment for plants and vegetation to grow; plants also photosynthesise so they encouraged the increase of oxygen in the atmosphere even further, sustaining a suitable environment for the Animalia kingdom to evolve. Thanks to this, we now have a huge range of different modern species of animals and plants.
The utility<span> approach </span>helps explain the law of demand<span>. In fact, the </span>demand<span> curve for a normal good is downward sloping due to the </span>law<span> of </span>diminishing marginal utility<span>.</span>