Answer:
B
Explanation:
Crossing over is the process involved during meiosis of two chromosomes sharing genetic information with each other from each parent. This happens so the two daughter cells or sister chromatids have a variety of genetic information and so they are not completely identical. This leads to genetic diversity or variation.
It is important in determining whether injuries/death was an accident or purposeful, and if purposeful, who, how and why did someone do it. They determine the weapon through the ligature marks left, the shape, force and impact of the injury, the location of the injury, and by analysing any fragments and trace evidence left on the wound
Answer:
Phoebus Levene( 1896, Sagor Russia - Septemeber 1940, New York)
Explanation:
These were developed by Phoebus Aaron Theodor Levene ,he was a russian who studied medicine, with keen interest in organic chemistry.
He migrated to the US in 1891, and started practising medicine in 1892.Due to his strong interest in research he combined research(1894) in molecular structure of sugars with medical practice,But this was cut short when he contracted tuberculosis.
Between 1896- 1906,he collaborated with many nucleic acids and protein exoperts e.g Albrecht Kossel and Emil Fischer to wok on the structure of DNA.And headed the Rockefeller Institute for Medical Research.
He works included :the isolation of Nucleotide-monomers of DNA
:the isolation of D-ribose sugar from ribonucleic acid molecule.(RNA)
Discovery of 2-deoxyribonucleic ,
How the components of Nucleotide(phosphate group,sugars, and organic bases) combined to form nucleotide, and how the latter undergo condensation reaction to form DNA.
Answer:
RNA world hypothesis.
Explanation:
RNA is present as the genetic material in some viruses only. RNA is produced from the template DNA by the process of transcription and helps in the protein gene expression.
According to RNA world hypothesis, RNA is considered to be the first genetic material as it has the ability to store the genetic material. The oxyribose sugar makes the RNA more reactive than the DNA molecule. The RNA also has the ability to work enzyme known as ribozyme. Hence, RNA has the ability to store the information and acts as catalyst.
Thus, the answer is RNA world hypothesis.
<span>Because they are composed of material that is denser than that of the continental crust. As such oceanic crust is less buoyant than continental crust and so where oceanic crust collides with continental crust, the oceanic rust tends to be forced beneath the continental crust.</span>