Oxygen is an abiotic factor that is beneficial by-product of primary production.
<u>Explanation:</u>
The non living parts of an ecosystem that mainly affects the living organisms in it are called as an abiotic factor. These can include soil, temperature, water, oxygen and sunlight. The major energy source in earth is Oxygen which is abiotic factor.
It is very essential for the photosynthesis process to take place. Here, the plants converts water and carbon dioxide into oxygen and sugar. This becomes food for plants. Then these plants are eaten by animals. Thus oxygen is an important and beneficial by-product of photosynthesis. Oxygen is also very important for the survival of human beings.
When there has been an error in copying a DNA, a DNA repair gene fixes its mistakes. However, a person having an error in his DNA repair gene (which are not corrected), it may lead to gene mutations with the possibility of leading to cancer. The mutations of DNA repair gene can possibly be inherited or acquired.
When chiasmata can first be seen in cells using a microscope, the following processes has most likely occurred in prophase I.
<h3>When chiasmata can first be seen in cells using a microscope?</h3>
Recombination can occur at any two chromatids within this tetrad structure.
Crossovers between homologous chromatids can be visualized in structures known as chiasmata, which appear late in prophase I.
Thus, option "C" is correct, Prophase I.
To learn more about prophase I click here:
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