Answer:
The correct answers are A and D
Explanation:
Internal fertilization is the process when the syngamy (union of male and female gamete) occurs inside the female body after insemination using copulation. In contrast, External fertilization is the syngamy outside the female body, that is in the outer environment especially in water bodies.
The approximate LD50 of the least toxic substance will be 130 mg/Kg.
- The dose necessary to cause the death of 50% of a population under test after a predetermined test period is known as the LD50 value for a drug.
- Commonly used as a broad indicator of a substance's acute toxicity are LD50 values.
- Greater toxicity is indicated by a lower LD50. A low LD50 of 500 mg/kg or less implies severe toxicity.
- Moderate toxicity is indicated by an LD50 of 500 to 1,000 mg/kg. A modest toxicity level of 1,000 to 2,000 mg/kg is indicated.
- The species is especially vulnerable to the poison if the LD50 is low. The lethal dose (LD50) of a specific poison might change significantly between several animal species.
- Thus out of all the options, LD50 130 mg/kg will have the lowest toxicity and 20 mg/kg will be the highest.
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Answer:
removal of introns, addition of 5' cap and 3' tail to mRNA.
Explanation:
The mRNA is processed before it leaves nucleus. The introns are removed and exons are remain in mRNA. This process is called splicing. The 5' end is attached with a cap and 3' is attached with a polyadenylated tail. Thus mRNA is processed with these process before it leaves the nucleus.
Answer:
The correct answer is "altering the equilibrium of ecosystems".
Explanation:
Ecosystem have a very complex and sometimes intricate equilibrium. Each species in an ecosystem have a role in the food chain, therefore, if humans affect the behavior of one species, undoubtedly, another species will be affected. In this case, insect populations are increasing as a result of birds modifiying they migratory behavior due to the presence of discarded food in the landfills. Most likely the increased insect populations will affect the plants population as well, creating a series of events that alter the equilibrium of the ecosystems.