Dr. marshall demonstrated that gastric ulcers are caused by a bacterium by using Koch’s postulates.
Koch’s postulates are four standards created to confirm a causative relationship between a microorganism and a disease. Koch’s postulates were formulated in 1884 by Robert Koch and Friedrich Loeffler. Koch’s postulates include;
- the microorganism must be found in every cases of the disease.
- the microorganism must be isolated from the diseased host and grown in pure culture
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- the cultured microorganism must cause the disease when introduced into a healthy laboratory animal
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- the microorganism must be re-isolated from the new host and identified to be the same as the original causative agent
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Answer:All living things are made of the same basic building blocks, cells. A human is made of 65 trillion cells. Cells are everywhere, on you skin, in your blood, and even on your tongue. In fact, your blood is clear but red blood cells are what make your blood red. Most living things are made up of many cells but some are made of only one cell, like amebas, paramecium, fungi, protists, monerans, and bacteria.
There are two basic types of cells, animal cells and plant cells. They have some common parts found in both and other parts that are unique to each. A cell membrane is found in both plant and animal cells. It is the structure that surrounds the cell and protects it. Plant cells have a cell wall, a rigid structure surrounding the cell membrane. Animal cells do not have a cell wall. Cytoplasm is the thick, jelly-like substance that makes up most of the cell. Vacuoles are fluid filled sacs in the cell. The vacuoles contain stored water or food that will be used by the cell. Cells also contain other "small organs" called organelles that carryout various cell functions. And then there is the control center of the cell, the nucleus, surrounded by a protective outer covering call the nuclear membrane. The nucleus contains the DNA, or chromosomes, that carries all the instructions on how a cell will function, live, and reproduce.
Every cell needs to energy to live and reproduce. Plant and animal cells obtain energy in different ways. Animals can not make their own food. They obtain energy by taking in food, water, and oxygen and converting it to sugar. Sugar is the only food a cell can eat. Plant cells can make their own food from water and sunlight. This process is called photosynthesis. Both plant and animal cells use energy from the food they obtain to reproduce.
All living things produce more living things. Cell reproduction is called mitosis.
Explanation:
Answer:
populations
Explanation:
this is because individual species are not changing. Populations are evolving. Since people in a group differ, those of the population are more able to live and replicate owing to a specific range of environmental conditions.
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