Answer:
Four conditions are needed for natural selection to occur: reproduction, heredity, variation in fitness or organisms, variation in individual characters among members of the population. If they are met, natural selection automatically results.
Explanation:
hope that helps!
-conducts electric current
-forms crystalline solids
-brittle
The right option is; Brittle
Metals are substances or chemical elements that form a metallic bond with other metal atoms. Metals are usually lustrous, ductile, opaque, malleable, and good conductors of heat and electricity. Metals form crystalline solids at room temperature and they are not brittle. Examples of metals include copper, silver, iron, mercury and sodium.
Brittle is not a characteristic of the metals.
Further Explanation:
Metals are chemical substances that are inorganic in nature. The most abundant possess are sodium, magnesium, iron, aluminum, and calcium. The copper, platinum, silver, gold not readily react with other elements so they are present in free-state. The characteristics of metal are:
Metals are mainly crystalline in nature. The crystal structure of metals is very simple with a relatively high degree of symmetry. The metal reacts readily with other non-metal. The reactivity of metals are different from each other, lithium and potassium are highly reactive metal compound. The platinum, palladium, gold, and silver are very low reactive compounds. The metals are usually malleable and ductile in nature that means they can be transformed into wire and sheet. The brittle substances do not possess these characteristics and therefore, brittleness is not a characteristic of metals.
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Answer Details:
Grade: High School
Subject: Biology
Chapter: Metals and Non-metals
Keywords:
Substance, compound, metal, crystalline, gold, potassium, lithium, silver, malleable, brittle, ductile, hard, reactivity, electricity, conductivity.
B. Catalase in an enzyme that slows down the reaction.
C. Catalase is a reactant that gets used up in the reaction.
B) be evaluated through experimentation
C) a be refined after evolution
D) acts as a universal principle
D) acts as a universal principle
It's D because a hypothesis is just an educated guess(sort of) of what you think happens. A universal principle is the exact opposite of that.
The vaccine wears out over time?
The flu virus changes every year <----?
The body eliminates the vaccine
Answer:
The correct answer would be the third option.
Vaccination refers to the administration of weekend or attenuated microorganism or antigen in the body. It helps in developing adaptive immunity in the body.
Thus, vaccine neither wears out with time nor body eliminates the vaccine.
However, the flu virus changes every year due to the short life cycle. Consequently, the memory B cells cannot recognize changed virus due to which the body loses its immunity against the virus.
This is why doctors recommend that people should get flu shot each new flu season.
Answer:
Parasitism
Explanation:
Parasitism is the association between two organisms in which one organism (parasite) is benefited while the other (host) is harmed. The parasite is a heterotrophic organism that derives its nutrition from the living tissues of the host organism. In the given example, tick suck blood from their host and are exhibiting parasitism.