Which characteristic is used to classify galaxies? the size of the galaxy the shape of the galaxy the presence of dust and gas between stars the presence of active star formation sites

The commonly used classification strategy for galaxies is based on one that was developed by Edwin P. Hubble and improved by an astronomer named Gerard de Vaucouleurs. It utilizes the three major kinds, and then much more divided by precise characteristics namely, the openness of spirals, size and extent of bars,and the size of galactic bulges. The sub-classifications also  include the age spectrum of its stars and the markers for such characteristics as a galaxy’s star-formation ratio in this age of multi-wavelength observing.

the shape of the galaxy

answer; /// i believe the correct answer is (thrombocytopenia); (a)

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.