Answer is B. Porifera
Members of the phylum porifera includes animals which lack tissues. These animals are also called sponges. These are the simplest multicellular animals. Even though they are multicellular, they do not have any tissues or organs. They have cellular level of body organization. Sponges are aquatic animals and water plays a major role in the feeding, exchange of gases and as well as excretion.
Sarah should found a Gills when she observes closely and dissecting the organism. A gills is what species in the water use for breathing, when people or human have lungs to breathe, fish or underwater species use gills to breathe in water. It is a respiratory organs of animals especially fish.
Explanation:
Nondisjunction: Failure of paired chromosomes to separate (to disjoin) during cell division, so that both chromosomes go to one daughter cell and none go to the other. Nondisjunction causes errors in chromosome number, such as trisomy 21 (Down syndrome) and monosomy X (Turner syndrome). It is also a common cause of early spontaneous abortions
