Answer:
Fossil fuels, including coal, oil and natural gas, are currently the world's primary energy source. Formed from organic material over the course of millions of years, fossil fuels have fueled U.S. and global economic development over the past century. Yet fossil fuels are finite resources and they can also irreparably harm the environment. According to the U.S. Energy Information Administration, the burning of fossil fuels was responsible for 76 percent of U.S. greenhouse gas emissions in 2016. These gases contribute to the greenhouse effect and could lead to potentially catastrophic changes in the Earth’s climate. Technologies such as Carbon Capture and Storage (CCS) may help reduce the greenhouse gas emissions generated by fossil fuels, and nuclear energy can be a zero-carbon alternative for electricity generation. But other, more sustainable and less risky solutions exist: energy efficiency and renewable energy.
Answer:
Made mostly of collagen, bone is living, growing tissue. Collagen is a protein that provides a soft framework, and calcium phosphate is a mineral that adds strength and hardens the framework. This combination of collagen and calcium makes bone strong and flexible enough to withstand stress.
Answer:
Medulla.
By analyzing the DNA extracted from the hair follicle, the medullary index and the pattern of medulla in the hair samples obtained from a crime scene, an investigator can identify the owner.
Explanation:
The hair consists of follicle and shaft. The follicle is the part of the skin, where the hair grows and the hair shaft has three layers: an inner medulla, a cortex, and an outer cuticle.
The morphology (physical characteristics) of hair provides a broad detail on the racial background of an individual and an investigator can identify a group of people who share similar traits. But the hair without follicle cells attached to it, cannot be used to identify a specific individual. If the follicle of a hair is present, then it can lead to individual identification by DNA analysis. Also the medulla of animals is larger than that in the humans. By comparing the medullary index (the ratio of the diameter of the medulla to the diameter of the entire hair), it can be determined if the hair obtained from crime scene belongs to animals or humans. The macroscopic (length, color, and curliness) and microscopic characteristics ( pattern of the medulla, pigmentation of the cortex, and types of scales on the cuticle) of the hair samples are studied during a crime investigation. If the entire hair follicle (follicular tag) is present in the hair samples found at the crime scene, the blood and tissue attached to the follicle is extracted and analyzed using DNA profiling. DNA analysis of the hair follicle provides an identification with greater accuracy than the hair shaft.
Answer:
The muscles of the eye cover a greater number and in turn carry out greater fine motor skills.
Explanation:
Alpha motor neurons are neurons that invent the skeletal muscle, that is, striated, so that through the motor plate that is the unit that unites them, an action potential is transmitted that contracts the sarcomeros of the elastic fibers and the z lines. come closer, each eye movement is much more precise than the locomotion of the lower limb, which carries greater innervation in each muscle bundle due to the specificity of the movement, this is how more alpha motor neurons are required to mobilize the eye than a leg.
