Answer:
A. 90%
Explanation:
Only 10% can transfer from level to level.
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.
The organisms in a pond and the physical factors influencing them best describes an ecosystem.
Answer:
The dura mater and pleural contain fluid which lubricates the brain and lungs respectively.
Explanation:
Dura mater is the outermost layer and a sac in the brain that envelope arachinoid and it's surrond venous channels which carried blood from the brain to the heart. The dura mater contain cerebrospinal fluid and drains it from the brain to the internal jugular vein
The pleural help in the proper functioning of the lungs and it supply pleural fluid which lubricates the lungs and allow for respiration.
