Answer:
"Macrophages" cells are commonly dispersed (mixed in) with simple columnar epithelial cells. They are responsible for secreting mucus.
Explanation:
When researchers create lesions, they are destroying a piece of the brain.
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.
Answer: muscle contraction of sustained force resulting from repeated action potentials. (Option A)
Explanation: Tetanus is also called physiologic tetanus. Tetanus refers to the contraction of the muscle, which is established when the motor nerve that supply nerves to a skeletal muscle produces action potentials at a very high degree.
However, tetanic contraction is usually a normal process (such as when carrying a heavy box). Also, muscles can be shorten, lengthen or remain constant length during tetanic contractions.