Answer:
They have a gizzard to grind the food.
Explanation:
Birds cannot chew since they have no teeth. However, the beak allows them to split very large seeds or swallow them directly.
For their digestion they have a stomach where digestion enzymes are released. Also they have a gizzard that is an organ that grinds the food mechanically. This gizzard usually has small stones inside that were previously ingested and that helps to digest the food.
Answer:
Channel proteins and Carrier proteins
Explanation:
These are type of membrane proteins that transcend the entire length of phosphoslipid bi- layer in the plasma membrane.They facilitate the movement of ions and molecules across the walls of the plasma membranes.
Generally, substances like glucose, amino acids, are too large to pass through the phopholipid bilayers. Likewise ions of potassium, sodium calcium, because of their polarities can not pass through either. They are ferried across the phospholipid by group of protein structures called channel proteins. Some are also transported across by carrier proteins. The process by which these protein structures aided the diffusion of substances across the phospholipid bilayer is called Facilitated diffusion.
Channel proteins are pores, that are filled with water molecules with the entrance well gated. That is the entrance is controlled by part in the inner structure of the protein which can open or close the pores like a gate to control the movement of ions across it. e.g Sodium channels are gated for movement of sodium ions by voltage or ligands(chemicals) during nervous transmission to elicits action potential. Like wise Potassium channels allow diffusion of potassium ions across the phospholipid bilayers. it gates are shut when sodium channels are open; this regulate ion exchange.
Their structures are well fixed in shape , specific to the substance or ions being transported;and the rate of diffusion depends on the like hood of opening of the gate or closure.
Carrier molecules also in the membranes do not have a fixed shape, and their transport direction is determined by the direction of concentration gradients. Thus they can flip on either sides of the membranes to aid diffusion across. Their movement can be both passive and active, and the rates of diffusion depends on the number of available carrier proteins in the membrane. They are also specific to the ions they transport.And are not gated,
Therefore these two membrane integral proteins facilitate movements of substances across the phospholipild bilayers
Sweat, tears, skin, and mucous membranes are among the physical defenses that keep a person from being sick.
<h3>What causes infectious diseases?</h3>
Coming into contact with a person or an animal who has the virus is one of the most straightforward ways to obtain the most contagious or infectious diseases. Direct contact, such as person-to-person contact, can transfer contagious diseases. Direct transmission of bacteria, viruses, or other germs from one person to another is the primary method by which contagious diseases are typically disseminated. If someone who is unaffected touches, kisses, coughs, sneezes, or has the virus or bacterium on them, this could happen. Additionally, these pathogens can disperse through sexual contact and the exchange of bodily fluids. The person who spreads the infection may only be a carrier and not exhibit any signs of the illness.
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The vaccine used to prevent measles consists of live measles viruses. This type of vaccine is most likely <u>MMR vaccine</u>
MMR vaccine means Measles, Mumps, and Rubella vaccine.
