Answer:
4. The suspected causative agent must be isolated from the diseased host and grown in pure culture
Explanation:
Robert Koch (1843-1910) was one of the most important bacteriologists of all time. Famous for discovering the tuberculosis bacillus (precisely on March 24, such as today, in 1882), he also discovered the cholera bacillus and is considered the founder of bacteriology. He worked on the isolation of infectious agents and reinfections from pure cultures, experiences from which he established the "Koch Postulates".
These postulates have been taken as a reference that describes the etiology of all the causative agents of an infectious disease, although they were originally used to describe only the tuberculosis bacillus. They are the following:
1- The agent must be present in each case of the disease and absent in the healthy.
2- The agent should not appear in other diseases.
3- The agent must be isolated in a pure culture from the lesions of the disease.
4- The agent has to cause the disease in an animal that can be inoculated
Answer:
A) They form covelant bonds
Explanation:
covelant bonding occurs when pairs of electrons are shared by atoms.
Forest biome: It gives us medicinal plants, woods for commercial purpose. Forests provides us rubber and fibers that is very important for the industries for making various products. They also contribute to perform ecological functions such as carbon storage, nutrient cycling, water and air purification. It also provides habitat to the wildlife.
Freshwater biome: We use fresh water for drinking water, irrigation, sanitation systems, and in industrial factories. Water used from groundwater, rivers and lakes is regained by rain and snowfall.
Marine biome: It serves huge amount of oxygen into the environment and absorbs the atmospheric carbon dioxide.
As a result of the activity of human there is a significant decrease in the number of trees. The products now used are synthetically made which were made up of natural fibers previously. The water source such as rivers, lakes, and ponds are polluted due to which many water borne diseases are increasing day by day. The accumulation of waste which are found in marine biome are reducing the number of flora present inside marine ecosystem.
Answer: Several types of evidence supported Hess's theory of sea-floor spreading: eruptions of molten material, magnetic stripes in the rock of the ocean floor, and the ages of the rocks themselves. This evidence led scientists to look again at Wegener's hypothesis of continental drift.
Explanation:
<h3><u>Answer;</u></h3>
The law of independent assortment
<h3><u>Explanation;</u></h3>
- The Principle of Independent Assortment illustrates how different genes individually separate from one another when reproductive cells receive.
- Independent assortment of genes and their similar traits was first mentioned by Gregor Mendel in 1865 during his studies of genetics in pea plants.
- When two or more characters are acquired, individual hereditary factors classify independently during gamete production, giving distinct traits an equal opportunity of befalling together.
