Answer:
Every fossil tells us something about the age of the rock it's found in, and index fossils are the ones that tell us the most. Index fossils (also called key fossils or type fossils) are those that are used to define periods of geologic time
Explanation:
Snails are present in most of the world, so it is not a surprise to discover that they dwell in diverse habitats. Some of them are comfortable in the desert while others live in ditches and cooler climates. These include mountain areas and even marshes
Answer:
This can be explained based on structure, and on metabolisms of carbohydrate.
Explanation:
Carbohydrate has a relatively simple structural composition than the either protein or fatty acids. The C, H and Oxygen molecules are of relatively fewer in number and few chains than fats and protein.Thus cells will spend less energy to break bonds(catabolisims) among these molecules during cellular respiration pathways to trap the energy.
In addition glucose the end products of carbohydrate did not need any processing before it enters glycolysis, Kreb's Cycle and oxidative phosphorylation pathways to generate energy for the cells.
Conversely, for protein to be used it has to be first deaminated(removal of amino acid) by the liver before it enters glycolysis,while fats needs to be broken down and undergo beta oxidation with the long chains removed before it can form acetyl CoA. Therefore cells will prefer few steps, less endergonic pathways of glucose than longer more endergonic amino acids and fatty acid pathways.
Furthermore, glucose can be used in cellular respiration to produce energy either aerobically or anaerobically, while fats can only be used anaerobically. Therefore, since cells usually prefer to thrive in aerobic conditions they breakdown glucose easily during this period, and when lack of oxygen occurs they switched to anaerobic, Thus, the versatility of glucose to oxygen concentration makes glucose a better choice. Besides if fats was used anaerobically, ketone bodies build up which may be toxic to the cells.
Answer:
The protons and the neutrons are found in the nucleus of an atom.
Explanation:
Atoms are best described as the smallest unit of any matter.
Protons can be described as part of an atom which carries a positive charge. The protons are enclosed in the nucleus of the atom.
The neutron is the part of the atom that carries zero charge. The neutron is also enclosed in the nucleus of the atom.
The electrons can be described as the part of an atom that carries a negative charge. The electrons move around the nucleus in orbits.
The answer is D, white blood cells.
The main function of white blood cells is to defense the body from bacteria or other pathogens. There's 2 main kinds of white blood cells, lymphocytes and phagocytes. Lymphocytes mainly produce antibodies that can kill bacteria or any pathogens, and phagocytes can ingest the pathogens directly.
Therefore, since the white blood cells can protect our body, they're part of our immune system.
