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
Is there suppose too be a photo attached because if so it’s not
Answer:
<h2>D. Competitively dominant to other organisms in the ecosystem</h2>
A keystone species is an organism that helps define an entire ecosystem. Without its keystone species, the ecosystem would be dramatically different or cease to exist altogether.
<em>Hope that helps! :)</em>
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<em>-Aphrodite</em>
Explanation:
Answer:
hemoglobin
Explanation:
Cytoplasm of RBCs contain large amount of hemoglobin which contain iron binds to haem group. it carry and transport oxygen from lungs to all parts of body and return carbondioxide back to the lungs from the different tissues.
Normal level of hemoglobin for men= 13.5 to 17.5 g/dl and for women =12.0 to 15.5 g/dl
Low level of hemoglobin is the indication of anemia
Answer: B. by toxic chemicals (in smoke) or radiation that can damage the DNA in cells.
Explanation:
The carcinogens presents in cigerates covalently bind to DNA and form DNA adducts which results into miscoding (e.g., insertion of the wrong base) during replication of DNA and this genetic mutation causes uncontrolled cellular growth which causes cancer.
Ionising radiation including X-rays, radioactive particles, and gamma rays,can cause cancer by damaging DNA. high-energy radiation damages DNA and cause genetic mutation same as cigerates and causes cancer.
Both toxic chemicals (in smoke) or radiation damages DNA inthe cells which leads to cancer.
Hence, the correct option is B.
