Astronomers have seen stars forming within a nebular cloud. As the nebular cloud condenses and its own gravitational attraction collapses it, heat and energy build up creating a planet.
Answer:
Double fertilization involves two sperm cells; one fertilizes the egg cell to form the zygote, while the other fuses with the two polar nuclei that form the endosperm. After fertilization, the fertilized ovule forms the seed while the tissues of the ovary become the fruit.
It is regularly hard to separate the elements of the apprehensive and endocrine system since it is hard to separate between the anxious and endocrine systems since a few neurons emit hormones and some endocrine organs react to neural signs.
The endocrine system is not a piece of the nervous system, but rather it is as yet basic to correspondence all through the body. This system is made out of organs, which emit concoction ambassadors known as hormones.
The properties are:-
1. Water is polar. Water molecules are polar, with partial positive charges on the hydrogens, a partial negative charge on the oxygen, and a bent overall structure. This is because oxygen is more electronegative, meaning that it is better than hydrogen at attracting electrons.
2. Water is an excellent solvent. Water has the unique ability to dissolve many polar and ionic substances. This is important to all living things because, as water travels through the water cycle, it takes many valuable nutrients along with it!
3. Water has high heat capacity. It takes a lot of energy to raise the temperature of a certain amount of water by a degree, so water helps with regulating temperature in the environment. For example, this property allows the temperature of water in a pond to stay relatively constant from day to night, regardless of the changing atmospheric temperature.
4. Water has high heat of vaporization. Humans (and other animals that sweat) use water’s high heat of vaporization to cool off. Water is converted from its liquid form to steam when the heat of vaporization is reached. Since sweat is made mostly of water, the evaporating water absorbs excess body heat, which is released into the atmosphere. This is known as evaporative cooling.
