Discovery In 1928 it was discovered by Frederick Griffith in an experiment generally known as transformation.
Experiment
In his experiment he considered two strains of <em>streptococus pneumonia,</em> one was R-type which was non-virulent and cause no disease in mice, other was virulent and S-type which cause disease and at last death of mice.
This experiment was comprised of four steps which are as follow:
Step 1: First he injected living strain of S into mice, after sometime mouce died.
Step 2: He injected living strain of R into mice, the mice alive as he did not got any disease.
Step 3: He injected heat killed strain of S into mice and mice remain alive.
Step 4: He mixed living R strain with heat killed S strain and then inject into mice. As a result the mice died.
Conclusion: It was found that genetic material from heat killed S stain were transferred to living R (non-virulent) strain, as a result R become virulent and cause the death of mice.
Answer:
The greenhouse and enhanced greenhouse effects refer to the return of approximately <u>80</u> percent and greater than <u>80</u> percent of the heat radiated by Earth.
Explanation:
During natural greenhouse effect :
. Solar radiation reaches the earth
. Re-radiation of heat occurs
. Less re-emitted heat
. More heath escapes into space
Hence the greenhouse effect refers to return of 80% of heat radiated by Earth.
While during Human Enhanced Greenhouse effect :
. Solar radiation reaches earth
. Re-radiation of heat occurs
. More re-emitted heat
. Less heat escapes into space
Hence the enhanced greenhouse effect refers to return of more than 80% of heat radiated by Earth .
During fertilization, the encounter of gametes results in the fusion of their nuclei. The nucleus of the egg cell thus formed is therefore a mixture of the two nuclei.
So the parent will only give half of his chromosomes, so the child will have 50% of his chromosomes that resemble each of his parents.
Another factor that must be mentioned is the genetic recombination between the chromosomes that occurs during meiosis of the reproductive cells. Thus, this will give a heterogeneous chromosome resulting from recombination of the two chromosomes of each of its parents, and the child will have a unique combination chromosome but keeping the alleles of both parents.
C. Statement 1 is about an everyday life theory, and statement 2 is about a scientific theory.
Explanation - Statement 1: Children knocked over the trash can while cycling is an example of everyday life theory whereas Statement 2: Plant cells generate from sunlight and chlorophyll is an example of scientific theory.
In everyday life, if Children are not taught or explained, then they tend to throw the garbage or trash here and there thereby littering the street. Applying the scientific theory, plant cells uses sunlight, water, carbon dioxide and chlorophyll to perform photosynthesis.
Answer: b
Explanation: Mitosis produces 2 cells where has meiosis produces 4 and 2 is half of 4
(plus I just took a test with this question)