Chapter 6 And 7

Essential nutrients are necessary for the proper functioning and survival of an organism. These nutrients cannot be synthesized by the organism itself and must be obtained from external sources, such as food or the environment. Without these essential nutrients, the organism may experience deficiencies that can lead to various health problems or even death. Therefore, the provision of essential nutrients is crucial for the well-being and sustenance of an organism.

Methanogens are a type of chemoautotroph that can produce methane gas in the absence of oxygen. Chemoautotrophs are organisms that obtain energy by oxidizing inorganic compounds, such as hydrogen gas, and use this energy to convert carbon dioxide into organic molecules. Methanogens are unique in their ability to produce methane as a byproduct of their metabolic processes. They are commonly found in environments such as swamps, marshes, and the digestive tracts of animals, where anaerobic conditions prevail. Methanogens play a crucial role in the global carbon cycle by contributing to the production of methane, a potent greenhouse gas.

Caspids are protein coats that enclose and protect their nucleic acid.

Nitrogen is the correct answer because it is one of the elements that make up 96% of the cell. The question states that the cell is composed of carbon, hydrogen, oxygen, phosphorous, sulfur, magnesium, potassium, nitrogen, and zinc. However, the other elements mentioned (magnesium, potassium, and zinc) are not part of the 96% composition, while nitrogen is included in the list of elements that make up the majority of the cell.

Lack protein synthesizing machinery.

Louis Pasteur is credited with postulating that rabies was caused by a virus. Pasteur conducted extensive research on rabies and made significant contributions to understanding the disease. He developed a vaccine for rabies and successfully tested it on animals, which led to the prevention and treatment of this deadly infection. Pasteur's work on rabies and other diseases laid the foundation for the field of microbiology and revolutionized our understanding of infectious diseases.

Prions are misfolded proteins that do not contain nucleic acid. Unlike viruses, which have nucleic acid (DNA or RNA) surrounded by a protein coat called a capsid, prions consist solely of abnormal proteins. Prions are known to cause various neurodegenerative diseases, such as Creutzfeldt-Jakob disease and mad cow disease, by inducing other normal proteins to adopt the misfolded conformation. Therefore, prions are a unique class of infectious agents that can propagate without the need for genetic material.

they survive on inorganic substances.