The influence of climate is due to basically two factors: temperature and rainfall. Climate indirectly affects soil formation through its influence on organisms as well. High temperatures and rainfall increase the degree of weathering and therefore the extent of soil development.
Answer: Option C.
Explanation:
Tumor suppressor genes are genes that help to control cell growth or division. It cause the production of protein which is important in cell growth. It encode protein that slow or inhibit progression in a specific stage of cell cycle leading to DNA repair or cell adhession. If the cells grow uncontrollable, it leads to cancer. When there is mutation of tumor suppressor genes,it result in reduction in its function.
Answer:
A. Mediator
Explanation:
Enhancers are cis regulatory sequences which are located very far - off from promoter sequence either upstream or down stream. They are capable of showing their impact even if they located far apart from promoter and Loop/Combinatorial model best describes the mechanism of action of enhancers.
The sequence of events are mentioned as under:
(1) First of all, activator binds to the enhancer;
(2) Co-activator which is also known as mediator binds to the activator;
(3) Chromatin remodelers bind with mediator at one end and heterochromatin on the other end so as to remove histones from heterochromatin and cause decondensation;
(4) General transcription factors (GTFs) bind the promoter;
(5) RNA polymerase II binds the promoter.
The enhancer forms a loop with the help of activator and mediator to reach near at promoter. In eukaryotes, activator does not interact with RNA polymerase directly, it interacts with the help of mediator so we can say that enhancer shows it's impact through protein-protein interaction.
Answer:
d. The two genes are closely linked on the same chromosome.
Explanation:
In a testcross involving F1 dihybrid, parent with both the recessive traits is crossed with the F1 dihybrid. Offspring is expected in 1:1:1:1 ratio because formation of gametes is a random process and parental type and recombinant type gametes are expected to be produced in same numbers.
If the two genes are present near to each other on same chromosome they can exhibit linkage. They show tendency to get inherited together. Hence new recombinants are produced in lesser number than the parental type offspring.