The type of immunity that provides lifetime immunity for the body against a specific pathogen is called acquired immunity. It is also referred to as adaptive or specific immunity.
Acquired immunity is not present at birth. it is learned. As a person's immune system encounters foreign substances (antigens) the components of acquired immunity learn the best way to attack each antigen and begin to develop a memory for that antigen. Acquired immunity is also called specific immunity because it tailors its attack to a specific antigen previously encountered. Its uniqueness lies in its ability to learn, adapt and remember.
Acquired immunity takes time to develop after first exposure to a new antigen. However afterward, the antigen is remembered, and subsequent responses to that antigen are quicker and more effective than those that occurred after first exposure. Memory of a particular antigen is kept by the B and T lymphocytes.
<u>Answer:</u>
Ecosystem is the level of organization which includes a community, population, and an individual.
<u>Explanation:</u>
- An ecosystem is the dynamic system of biotic and abiotic components that helps to maintain the circle of life.
- In an ecosystem there are different species and population of those species that exist together within a physical environment that is composed up of soil, water, minerals as well as weather conditions and climates.
- In ecosystem, there is the food chain as well as food web. The change in any component of the biotic or abiotic component would bring about change in every other component. Each component is interrelated with one another in an ecosystem.
<span>Natural selection is the differential survival and reproduction of individuals due to differences in phenotype. It is a key mechanism of evolution, the change in the heritable traits characteristic of a population over generations.
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Which activities? I want to say the nucleus as it is the control center of the cell, but this is a vague question.
The correct answer is D. Heat is transferred by radiation in Step 1 and by conduction in Step 2
radiation- the process of heat moving through the air
conduction- the process of heat moving from one object to another object by physical contact
