Answer: a. True
Explanation: These postulates were formulated by Robert Koch as a result of his experiments with healthy and infected mice. The postulates are often used to determine if a phatogen causes a disease. These are:
- The pathogen must be present in sick individuals but not in healthy ones.
- The pathogen must be isolated from individuals and cultivated in a pure culture.
- The pathogen cultivated must cause sickness when it's injected in suceptible inviduals.
- The pathogen must be isolated from the injected individuals and must be exactly as the first one.
Answer:
B. the appearance of lichens and mosses in an area where a glacier has recently melted away
Explanation:
Ecological succession, which refers to the series of changes that occurs over time in an ecosystem, can be of two types namely: primary succession and secondary succession.
Primary succession is a succession that involves an area where no form of life has grown previously, hence, the area of land is barren e.g bare rock. Primary succession is first colonized by species called PIONEER SPECIES e.g. lichens, mosses etc.
According to this question, "the appearance of lichens and mosses (pioneer species) in an area where a glacier has recently melted away" is an example of PRIMARY SUCCESSION.
The Principle of <u>segregation</u> states that the 2 alleles present at each gene locus separate from one another during gamete formation and remain distinct.
What is principle of segregation?
According to the principle of segregation theory, every human has two alleles for each specific feature and functions, and these alleles separate throughout the development of gametes. In other words, in everycase, each gamete contains a single allele.
Therefore, The Principle of <u>segregation</u> states that the 2 alleles present at each gene locus separate from one another during gamete formation and remain distinct.
To learn more about principle of segregation
Here: brainly.com/question/2161501
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