In the early days of germ theory, contagious diseases were thought to be caused only by fungi or bacteria. In the 1890s, Dmitri Ivanovski filtered extracts from diseased tobacco plants and discovered that the disease could be transmitted to new plants through the filtrate. He hypothesized that something smaller than bacteria or fungi was responsible for the transmission of the disease. Which best explains how Ivanovski’s work led to a change in the germ theory?
He tried to promote his hypothesis as a law.
He used a new experimental method to test his hypothesis.
He used a more powerful bacterial strain than other scientists had.
He obtained results that confirmed what other scientists were thinking.

1: most common garden plants prefer loam — soils with a balance of different-sized mineral particles (approximately 40% sand, 40% silt, and 20% clay) with ample organic matter and pore space. however, some plants grow better in sandy soils, while others are well-adapted to clay soils.

2: available water capacity is the maximum amount of plant available water a soil can provide. it is an indicator of a soil's ability to retain water and make it sufficiently available for plant use. available water capacity is the water held in soil between its field capacity and permanent wilting point.

3: it is the same for all living things (plants and animals). it also includes very tiny organisms that our eyes cannot see. they are known as microorganisms, and include viruses, bacteria and fungi.