Answer:
DNA is the genetic material of all the living organism except some viruses. The structure and the characteristics of the DNA was well explained by Watson and Crick.
DNA is a double stranded molecule in which nitrogenous bases are linked together. Watson and crick explained that DNA strand are antiparallel. The antiparallel nature of the strand means one DNA gas a polarity of 5' to 3' direction whereas the another strand of the DNA gas polarity of 3' to 5' direction. These two strands has opposite polarity and runs in anti parallel directions. Thus, the DNA strand known as antiparallel strands.
Answer:
Both the nature of the gene and its environment can influence the mutation rate.
Explanation:
Mutations are caused by environmental factors known as mutagens.
Types of mutagens include
- radiation,
- chemicals, and
- infectious agents.
You subtract the number of protons and the mass to get the number of neutrons.
A contact lens is a lens placed on the cornea of the eye.
Importance of buffers in contact lens products:
Buffers: They aim to keep the pH of the solutions at values between 6.6 and 7.8 in order to maintain the lens parameters and the effectiveness of the solutions. They are made by the combination of an acid and its sodium salt (phosphate and acetate for example). Borate and citrate buffers are used.
Importance of isotonicity in contact lens products:
The solution composed by isotonic saline solution.
Isotonia is expressed by osmolarity or cryoscopic lowering
- 0.236 to 0.446 mOsmoles / l (increases during the day)
- If the osmolarity of the mixture is different from that of the tears, it causes discomfort and irritation
• Increased tear secretion
• Increase the blink frequency
- If hypotonia, entry of water to the epithelial cells, if hypertonia: inverse
- Osmolarity restored 1 or 2 minutes after instillation
