He is using an arthroscope. Which is use to examine a joint.
Traits are inherited by genes on a chromosomes from the Mother and Father of the Offspring.They are passed down from our parents to us and there is 26 different chromosomes which determine what you look like.
Answer:
Radiometric dating methods
Explanation:
Absolute dating is the process of determining an age on a chronological or specified time scale in which events occurred in archaeology and geology. Absolute dating can be determined by using properties of the atoms that make up materials.
The most common method of absolute dating uses by geologists is radiometric dating methods which is based on the natural radioactive decay of certain elements such as potassium and carbon found in the rocks. By comparing the ratio of parent isotope with a known half-life to daughter product in the rock, the age of the rock can be determined.
The carbon-14 isotope is used in radiocarbon dating, but is only useful for measuring recently formed rocks in the geologic past. The decay of Potassium-40 isotope known as potassium-argon (K-Ar) method allows dating of materials that up to 1,000 billion years old.
Its A. it prevents sperm from reaching the egg and fertilizing it.