Answer:
They digest without the use of teeth.
Explanation:
The food trickles from the crop into the bird's stomach (proventriculus or gizzard) where digestive enzymes are added to the mix and physical grinding of the food occurs. The gizzard is why chickens do not need teeth.
Top-down effects imply control through predation, including fishery, while
bottom-up effects imply control through food abundance, often thought to be driven by climate or nutrient load.
<h3>What is Top down regulation ?</h3>
The top-down effect refers to a higher trophic level influences the community structure of a lower trophic level through predation.
<h3>What is Bottom up regulation ?</h3>
The bottom-up effect means that a lower trophic level in the biological network affects the community structure of higher trophic levels by means of resource restriction
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Protein
Proteins are the most versatile
macromolecules in living systems and they play important roles in essentially
all biological processes. Protein makes up the capsid of a virus. The infective
extracellular form of a virus known as a virion contains at
least one unique protein synthesized by specific genes in the nucleic acid of
that virus. In almost all viruses, at least one of these proteins forms a shell
(called a capsid) around the nucleic acid. Certain viruses also have other
proteins internal to the capsid. Some of these proteins act as enzymes during
the synthesis of viral nucleic acids.
The phosphorus cycle does not include an atmospheric component because phosphorus does not cycle through the atmosphere. In comparison, important processes of the carbon and nitrogen cycle occur in the atmosphere.
The correct answer is C: the gravitational forces due to the sun and the moon cancel each other's effect.