Answer:
Natural selection is an adaptative mechanism that modifies gene frequencies (allele frequencies) in the whole population across generations
Explanation:
According to the evolutionary theory proposed by Darwin, natural selection is the main process that leads to evolution. Natural selection can be defined as a mechanism through which populations adapt and change. The organisms better adapted to their environment will have more chances to survive and reproduce, and therefore they will pass their genes (and favorable traits) to the next generation. This process is able to modify the allele frequencies in the whole population, thereby changing and adapting (i.e., evolving) across generations.
The body's nonspecific defiance against invading pathogens is known as innate immunity and includes the following:
mechanical barriers and surface secretions
1. The intact skin and mucous membranes of the body. These provide a high degree of protection against pathogens.
2. The sebaceous secretions and sweat of the skin contain bactericidal and fungicidal fatty acids that can kill bacteria and fungi.
3. Normal bacterial flora of the skin may produce various antimicrobial substances such as bacteriocines and acids.
Humoral defence mechanisms
1. Lysozyme. This is an enzyme found in most tissue fluids apart from cerebrospinal fluid, urine, and sweat. It can kill bacteria.
2. Interferon. Inhibits viruses from replicating
3. Complement. This is a heat labile serum that can destroy gram-negative bacteria.
Answer:
DNA replication is the process by which DNA makes a copy of itself during cell division. The separation of the two single strands of DNA creates a 'Y' shape called a replication 'fork'. The two separated strands will act as templates for making the new strands of DNA.
Explanation:
<span>Energy, water, and carbon dioxide are produced.,When the chemical bonds of the glucose molecule are broken, energy is released. The cell is able to store that energy in the chemical bonds of a special molecule called ATP.</span>
Answer:
The enzyme shows increased activity up to a certain temperature.
Explanation:
An enzyme is mostly a protein molecule/a biologist catalyst that speeds up the rate of a chemical reaction in a cell.
Enzymes lower the reaction's activation energy by attaching to the reactant molecule and positioning itself in a manner that readily facilitates chemical-bond breaking and forming process.
As the temperature increases, the rate of enzyme catalyzed reaction increases up to a maximum level (optimum temperature) and then decreases abruptly with any further temperature increase.This optimum temperature is 40°C for most animal enzymes.The abrupt decline in the rate of reaction after the optimum temperature is caused by the denaturing of enzymes by temperatures above 40°C.
