B. sexual selection, which alters allele frequencies in the gene pool.
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.
Answer:
Honestly i think that its Richness because its good to have a good amount of different species so that there is a good number of animals to create a food chain. The amount of animals in a population is important but its more important to have a variety of different animals so that all the populations have other animals to eat or survive off of.
Explanation:
to separate Earth's four hemispheres
