Well all your doing is writing a paragraph about variation and pressures that can change the characteristics of population along with an example
Answer:
Pollen sac of anther, stigma.
Explanation:
Pollen is synthesized inside the pollen sac of an anther. An anther is a part of male reproductive organ in plants which has many pollen sacs. In order for the pollen grain to fertilize an egg cell and central cell, it must reach the stigma of ovary. Once the pollen which has two sperm nuclei reaches the stigma, it starts growing and develops pollen tube so as to reach the embryo sac. Embryo sac contains 7 cells and 8 nuclei. It has 3 antipodal cells at the chalazal end, 1 central cell with 2 nuclei at center and at micropylar end it has 3 cells out of which two are synergids and 1 is egg cell which is situated in between synergids. One of the sperm nuclei fuses with central cell and another one fuses with egg cell as a result of this fusion, the central cell now has 3 nuclei while egg cell has 2 nuclei. The process of fusion of sperm nuclei with central cell is known as triple fusion and the structure later on develops into endosperm. The fusion of 1 sperm nuclei with egg cell produces zygote which later develops into an embryo. The formation of these two structures is known as double fertilization.
Answer: The correct answer is- H2O ( water).
Photosynthesis is a process by which green plants and algae prepare their own food ( using CO2 and H2O) in the presence of sunlight. It is primarily divided into two phase that is light dependent and light independent phase.
During light depednent phase ( that occurs in thylakoid membrane), solar energy is absorbed by chlorophyll and converted into chemical energy in the form of ATP and NADPH.
Water is required as splitting of water ( H2O) occurs in this phase that liberates electrons ( which are passed to reaction center chlorophyll), hydrogen ions, and oxygen atom ( which combine to form oxygen molecule).
Thus, H2O is the right answer.
1. goes from higher to lower
2. goes from lower to higher
