<u>Answer:</u>
Cyanobacteria start producing pure oxygen around 200 million years ago.
<u>Explanation:</u>
Many scientists believed that Earth did not have any oxygen. Cyanobacteria or the blue green algae are the microbes which produced oxygen for the first time with the help of photosynthesis. This was around 4.5 billion years ago: after Hadean eon.
They were very simple, but they produced oxygen in the early earth’s atmosphere. So, they brought evolution on earth. This “blue-green algae” exists in salt water, rocks and soils and play a major role in maintaining the ecosystem.
Answer:
Plants are under the Eukarya,
Bacteria fall under Bacteria,
and Animals/Fungi lie under Eukarya as well
Explanation:
Answer: Polar molecules have an uneven distribution of electrons that cause one end of the molecule to have a positive charge and the other to have a negative charge. ... This means that in a polar bond, the electronegativity of the atoms will be different. For nonpolar bonds the electronegativity of the atoms will be equal.
Explanation:
The <em>Hydra </em>offspring will also have 30 chromosome.
Explanation:
- Budding is a method of asexual reproduction.
- Asexual reproduction takes place through mitosis where diploid cells divide to give rise to identical cells with same chromosome number.
- Hydra reproduces through budding thus, if the parent hydra has 30 chromosome then the offspring will also have 30 chromosome.
Answer:
Option (A)
Explanation:
The African plate is usually referred to as the fourth major (largest) tectonic plates that cover the continent of Africa and a portion of both the Atlantic and Indian ocean.
This plate shares a convergent plate boundary with the Eurasian plate towards its western side, where the African plate being denser subducts below the lighter Eurasian plate
It shares a boundary with the two smaller plates namely the Somalian and the Arabian plate towards its eastern side.
Thus, the correct answer is option (A).