Answer:
The correct answer is -Sponges lack true tissue but have morevariation in cell type than animas in oter phylum.
Explanation:
Sponges are belong under phylum porifera which have diverse form encrusting sheets to volcano shaped mounds.
The tubes that contain in their body are differ in size from millimeter upto one meter.
The poriferans contain canal system and with help of this, they pump water which enters through a specialed pores called ostia that flows through canal called spongocoel and finally the water exits from their body through oscula.
The sponges show complex organization as their body contain single tube with 2 cell layer thick.
Ascon,leucon,sycons are the level of complexity.
A <u>desert</u> receives less than 10 inches, or 25 centimeters, of precipitation a year.
The right answer is A mutation.
Alteration of the genetic material (DNA or RNA) of a cell or virus that causes a change in certain traits due to the inheritance of this genetic material from generation to generation.
Abnormal modification of the DNA of a gene, either spontaneously during cell division, or under the influence of external agents called mutagens. This gene is modified to be transmitted to the daughter cells. Some mutations have no effect on the cell. Others are the first step in a long process of cancerization.
Rare are the mutations that are beneficial.
I don't have enough information but it could be natural selection or mutations.