All living cells have an electrical charge difference across their plasma membranes due to ionic imbalances, the inside of the cell being more negative than outside. This difference in charge…
CLASS MONOGENEA Monogenetic flukes have only one generation in their life cycle. Thus one adult develops from one egg. Therefore, these animals are named as monogenetic. Monogeneans are mostly external…
CLASS TURBELLARIA: THE FREE LIVING FLATWORMS Members of this class are mostly free-living. They are bottom dwellers in freshwater and marine environments. They crawl on stones, sand, or vegetation. Turbellarians…
A neuron is a specialized cell with a cell body containing nucleus, and extending from cell body two types of cytoplasmic processes: one or more dendrites, and a single axon.…
Q 1. Define the following terms: (a) Neuron, (b) axon, (c) dendrite, (d) myelin sheath, (e) afferent neuron, (f) efferent neuron, (g) interneuron or associative neuron, (h) neurolemocyte, (i) neurofibril…
COMMUNICATION IA- NERVES Introduction The nervous system is a rapid communication system that interacts continuously with the endocrine system to control coordination of body functions. In the vertebrates it plays…
CLASSIFICATION Phylum platyhelminthes has four classes: (a) Class Turbellaria They have over 3, 000 species. They are free-living and aquatic External surface is ciliated. They are predators. They possess rhabdites,…
PHYLUM PLATYHELMINTHES Phylum Platyhelminthes contains over 20.000 animal species. They show following characters: They are flat- worms. They range in adult size from 1mm or less to 25 m. Parenchyma…
THE Triploblastic Acoelomate Body Plan EVOLUTIONARY PERSPECTIVE Members of the phyla Platyhelminthes, Nemertea and Gastrotricha show following advance characters: They are first bilaterally symmetrical animals. Therefore, they are more Complex…
Choose the best choice for the statements from the multiple choices 1-In animals, structure and function have evolved together. Several results of this evolution are (a) protection (b) support (c)…
rubab
saadia