Cells, like humans, cannot generate energy without locating a source in their environment. However, whereas humans search for substances like fossil fuels to power their homes and businesses, cells seek their energy in the form of food molecules or sunlight. In fact, the Sun is the ultimate source of energy for almost all cells, because photosynthetic prokaryotes, algae, and plant cells harness solar energy and use it to make the complex organic food molecules that other cells rely on for the energy required to sustain growth, metabolism, and reproduction.
Cellular nutrients come in many forms, including sugars and fats. In order to provide a cell with energy, these molecules have to pass across the cell membrane, which functions as a barrier — but not an impassable one. Like the exterior walls of a house, the plasma membrane is semi-permeable. In much the same way that doors and windows allow necessities to enter the house, various proteins that span the cell membrane permit specific molecules into the cell, although they may require some energy input to accomplish this task
<span>Single covalent bonding
Covalent bonding is the type of bonding that takes place when two atoms share a pair of electrons with each other. In order to form a molecule, these two electrons are glued to one or more atoms. One important contribution of non-covalent bonding is the oxygen we breathe. On the other hand, polar covalent bonding happens when a pair of electrons are being shared unequally because one of the atoms spends way too much time with another electrons rather than with the atoms. </span>
Answer:
If the population ever exceeds its carrying capacity, then growth will be negative until the population shrinks back to carrying capacity or lower. Some disadvantages of having uncontrolled are the rapid urbanization associated with the population explosion and industrialization has created an imbalance in the ecology of the Southeast Region.
Explanation:
Answer: Sexual reproduction
Explanation:
First, you should understand that mutation (an change in the base-pair sequence of the genetic material, DNA) is the original source of all genetic variation; as such whatsoever will alter the frequency of alleles, even if it is evolution, it relies on mutation.
In contrast, sexual reproduction does not change the frequency of alleles in the gene pool, rather it ensures constancy through the meiotic cell division process
Answer:
Nerve agent
Explanation:
A nerve agent is a chemical in which on exposure to humans affects the functioning of the nervous system. These chemicals are known to disrupt the process by which messages are transferred to the organs from the nerve. This disruption occurs by blocking the activity of acetylcholinesterase, which is responsible for the catabolism of a neurotransmitter, acetylcholine.
On exposure to a nerve agent, the muscles of the body become paralyzed and early symptoms is production of excess mucous such as in runny nose, pupil constriction and also difficulty in breathing.
These agents are sometimes used in chemical warfare. Examples include sarin, tabun etc.
