Answer:
Atoms are the smallest units of matter that still retain the fundamental chemical properties of an element. Much of the study of chemistry, however, involves looking at what happens when atoms combine with other atoms to form compounds. A compound is a distinct group of atoms held together by chemical bonds. Just as the structure of the atom is held together by the electrostatic attraction between the positively charged nucleus and the negatively charged electrons surrounding it, the stability within chemical bonds is also due to electrostatic attractions. To illustrate further, consider the two major types of chemical bonds: covalent bonds and ionic bonds. In covalent bonds, two atoms share pairs of electrons, while in ionic bonds, electrons are fully transferred between two atoms so that ions are formed. Let’s consider both types of bonds in detail.
Explanation:
Answer:
D
Explanation:
Vitamin C is one of the vitamins that humans can't produce in their liver. They need this vitamin from the external environment in the form of food. About 75- 90mg/day is it's the normal dosage. So, option D is correct.
Answer: secondary succession
Explanation: An ecological succession can be defined as a change that occur in the biotic community of the ecosystem with respect to the changes that occur in the abiotic factors like water, soil and climatic conditions with respect to time.
Secondary succession can be defined as the changes that occur in an area which was previously occupied by the living species and the area was disturbed by either human intervention or natural calamity.
Brazil clear cut is an example of secondary succession because after the clear cut some precursors like seeds, roots and other parts of the plants or trees can support the regrowth of plants and trees. Initiating the succession again.
Answer:
Meiosis is important for organisms that reproduce sexually because it is the cell division that serves to obtain gametes or sex cells.
Explanation:
Meiosis is a reductive cell division, involved in the gametogenesis process, where from a diploid cell haploid cells called gametes are obtained.
The gametes, also called sex cells, are responsible for containing the genetic information that each individual will transfer to their offspring.
In sexual reproduction, the importance of gametes is that the paternal and maternal gametes unite in a process called fertilization, to give rise to a diploid cell called a zygote.
