<span>a. Fish have a single central heart; earthworms have several hearts.
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Multi cellular organisms are made up of billions of cells each specialized to a unique role and these cells are organized into structural and functional units such as tissues and organs.
For each cell and organ to function optimally, it requires oxygen and nutrients and needs carbon dioxide and metabolic waste taken away in a continuous, never ending process.
<span>A mechanism is needed to accomplish the important function of transporting the relevant materials to and from the cell. The circulatory system fits this bill splendidly. It is a specialized organ system which allows blood and lymph to flow through the entire body carrying nutrients such as glucose, amino acids and electrolytes as well as oxygen to each cell, at the same time carting away carbon dioxide and all sorts of metabolic waste over to excretory organs to be expelled from the body.
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Bacterial pathogen can multiply quickly within a small space
Answer:
SARS- CoV- 2 is a virus that infects human by the oral-respiratory way in which the virus enters the body and these viruses have spikes on their surface made of spike proteins that allow these viruses to bind with the infected cell.
The infected cells have ACE2 receptor that is protein present on the surface of the human cells. Binding allows the structural change in the virus to fuse and enter in the cell where viruses reproduce them selves with the cell with cell system.
Answer:
The scientific study of life, called <u>Biology</u><u>, </u>can be organized around several themes. As the biological hierachy builds from molecules on up to ecosystems, each level has <u> emergent properties</u> that result from interactions among component parts. Life's basic unit of <u>structure and function</u> is the cell, which occurs in two basic forms- prokaryotic and eukaryotic . As organisms interact with the environment, <u>nutrients and chemicals</u><u> </u>cycle within an ecosystem, while energy flows one way from sunlight -> chemical energy -> heat. According to the core theme of <u>evolution </u>all of life is related by common descent. Life was diversified as <u>natural selection</u> had led to the gradual accumulation of adaptations that fit populations to the environment.
Explanation:
Emergent properties- Properties that is exhibited by a group of individuals as a result of interaction among them.
Evolution- the process by which populations develop new characteristic and become more efficient than their ancestors.
Natural selection- A phenomena in which only fittest organisms of a population are allowed to survive in a given environment. This play a key role in evolution.
Answer:
The Earth's movement through space affects life on Earth
Explanation:
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