<h2>Given statement is false</h2>
Explanation:
According to dispersive model of DNA replication,DNA molecules are hybrids of parental and daughter DNA;In this model each individual strand is a combination of original and new DNA
Meselson and Stahl did an experiment on DNA replication using E.coli bacteria
- E.coli was grown in a medium containing heavy isotope of nitrogen,bacteria took up the nitrogen and used to synthesize new biological molecules,including DNA
- It was grown for many generations,the nitrogenous bases of the bacteria's DNA were all labelled with heavy nitrogen
- Bacteria were then switched to light nitrogen isotope and allowed to grow for several generations
- They then measured the density of the DNA using density gradient centrifugation
- This method separates molecules such as DNA into bands by spinning them at high speeds in the presence of another molecule, such as cesium chloride
- Each DNA produced two DNA molecules each with one new strand and one old strand called semi conservative replication(half of the parental DNA conserved in daughter DNA)
- Each DNA strand act as a template for synthesis of new strand
- Hence,dispersive model of DNA was eliminated and semi-conservative model of DNA replication was proved by the above experiment
The correct answer is A. A burst of speciation
Explanation:
Adaptative radiation is part of evolution and occurs when a single organism or species diversify into a wide range of species (speciation), this process is called "adaptative" because the speciation occurs due to changes in the environment that make challenging survival usually due to the reduction of resources available and therefore organisms change to adapt to new conditions. Additionally, in adaptive radiation, the new organisms share traits with their common ancestor but also have different and unique traits. Considering this, it can be concluded adaptative radiation a burst of speciation.
In the Human body which system functions in detecting and responding to Stimuli is called the Nervous System.
Its the first layer of protection in the atmosphere against radiation from the sun and its harmful U.V. rays.