The mesosphere extends upward above the stratosphere, temperatures decrease. The coldest parts of our atmosphere are located in this layer and can reach –90°C.
Answer:
DNA has a double- helix structure which means it has two strands. The DNA strands are made from sugar (Deoxyribonucleic), phosphates and nitrogenous bases. There are 4 nitrogenous bases, 2 purine and 2 pyrimidine. The 2 purine bases are Adenine and Guanine. The pyrimidine bases are Thymine and Cytosine. DNA gives our genes.
RNA is a single strand unlike DNA. The strands are made from sugar (ribonucleic), phosphate and the nitrogenous bases. There are 4 nitrogenous bases 2 purine and 2 pyrimidine. The 2 purine bases are Adenine and Guanine. However, the 2 pyrimidine bases are Uracil and Cytosine. The function of RNA is to contribute to releasing proteins based on our rRNA and tRNA and mRNA. This process is known as RNA and transcription.
Explanation:
Answer: C. Microevolution is small scale change to the gene pool of a population while macroevolution is larger scale changes that lead to speciation.
Explanation:
Microevolution can be defined as a small change in the gene frequency within a gene pool of the species, these changes will be inherited by the organisms and there will not be any drastic change at the species level. But in case of macroevolution the large scale change occurs at the genetic level, which retain for long. This leads to development of new organisms or results in speciation.
Answer:
Option B
Explanation:
Flight-or-flight response is a response or physiological reaction towards external stimuli. Systematic desensitization is a methodology to control anxiety during speech. Hence, these two are not relaxation techniques. Transforming novelty into familiarity is also a methodology to remain prepared during a speech by practicing it well. Visualization is a technique that helps our mind to relax by using imagination to reach a relaxed state of mind.
Hence, option B is correct
