Photo 51, showing x-ray diffraction pattern of DNA
Photograph 51 is the nickname given to an X-ray diffraction image of DNA taken by Raymond Gosling in May 1952, working as a PhD student under the supervision of Rosalind Franklin,[1][2][3][4] at King's College London in Sir John Randall's group. It was critical evidence[5] in identifying the structure of DNA.[6]
The answer is Sodium Fluoride
The excretory system allows animals to remove metabolic waste their bodies. Many of these substances are potentially toxic. in Mammals nitrogenous toxins like urea are expelled through liquid urine while in reptiles and birds the nitrogenous compounds are expelled as a solid. This allows birds and reptiles to use less water in the processes of metabolism.
Answer:
Answer is 2. Fibroblasts fail to divide.
Explanation:
Tissue culture experiment is the experiment where tissues are grown in an artificial medium. This involves the use of growth medium such as agar or broth. This process help to produce needed tissues in a short period of time.
Fibroblasts are cells which are found in the collective tissues, and they produce collagen. The collagen produced by the Fibroblasts play important role in tissue repair. Fibroblasts are regarded as the main cells in the connective tissue.
Note that, PDGF, which is Platelet -derived growth factor in full, is a growth factor regulating cell growth and it's division.