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;
-They are absorptive interfaces with the environment.
Explanation;
-The important point is that the surface area to the volume ratio gets smaller as the cell gets larger. Thus, if the cell grows beyond a certain limit, not enough material will be able to cross the membrane fast enough to accommodate the increased cellular volume.
-The surface area to volume ratio of an object is the relationship between two measurements. It is the ratio of Surface area to volume. It shows the comparison between the size of the outside of an object and the amount inside. Small or thin objects have a large surface area compared to the volume.
A genotype is the genetic coding of a trait, so it's a paired combination of genes. A genotype has two alleles, which can be dominate or recessive, but overall the answer should be <span>a paired combination of genes</span>
1. outer covering - none of the other answers can occur due to the absorbed solutions inability to reach the centre of the organism, smaller cells in greater numbers are more efficient as they can group together yet all absorb the right amounts of nutrients for its need. multi cellular organisms, such as humans can have the other answers in them as cells group together to make skin, muscles and organs. it also gives the organism to grow larger.
2. bacteria are single celled. bacteria reproduce through mitosis (cell division). bacteria break down decaying matter to obtain energy. every organism requires energy to live. Bacteria can move in order to reach their nutrient source.
* Channel proteins- these are proteins with a hydrophilic pore where specific ions are able to pass through the membrane. Each channel protein is specific to an ion. This is the only way ions can travel through the membrane. They are trans membrane proteins.
* Carrier proteins- these are proteins which allow larger or polar molecules through the membrane. They are trans membrane proteins.
Carrier proteins essentially “carry" signals that are not soluble in aqueous solution through the blood stream to their target cells. Carrier proteins for hydrophilic signals prevent degradation of the signal. Channel proteins are embedded in cell membranes. They often are receptors (though not always), and when activated, allow specific ions to pass through the membrane.
A channel protein is a special arrangement of amino acids which embeds in the cell membrane, providing a hydrophilic passageway for water and small, polar ions. Like all transport proteins, each channel protein has a size and shape which excludes all but the most specific molecules
The carrier protein facilitate diffusion of molecules across the cell membrane. The protein is imbedded in the cell membrane and covers the entire membrane. This is important because the carrier must transport the molecule in and out of the cell.
