This is called internal fertilisation. It helps in maintaining buoyancy. Mollusca is the second largest animal phylum and includes about 85,000 species. They are known as acoelomates. They are characterized by digits which are clawed and covered with scales, exoskeleton in the form of feathers and the presence of a neck and beak.
Germ Layers and Organisation They are triploblastic and possess organ system level of organisation. Their eggs are more prone to environmental conditions and predators. An example of acoelomates is platyhelminthes. They are triploblastic with organ system level of organisation. Polyp is sessile, cylindrical structure with mouth and tentacles facing upwards, e. Answer: Arthropoda is the first phylum in which animals have properly developed organ systems. Locomotion The locomotory organ is muscular foot.
Nervous System It is ladder-like and consists of a brain and two main longitudinal nerve cords jointed at intervals by the transverse commissres. It is a type of development that involves a sexually-immature larval stage, having different food requirements than adults. Rhizopoda 1 There is no definite cell wall or pellicle 2 There is no definite shape 3 The locomotory organs are pseudopodia 4 There is no permanent mouth or anus. This kind of development is called direct development. Answer Birds have undergone many structural adaptations to suit their aerial life. Respiration It occurs through general body surface, gills e.
Class Common Name of Some Sponges 2. Notochord is present in vertebrates in the embryonic stage and hence all vertebrates are chordates. Those cnidarians which exist in both forms exhibit alternation of generation metagenesis. Toad, Frog Class — Reptilia · Skin is dry without glands. Animal Kingdom Classification System Class 11 Notes Download Pdf 1 Symmetry : Distribution of body parts around a 2 hypothetical axis.
Sexes are separate and exhibit sexual dimorphism. Respiration In terrestrial forms respiration occurs through lungs. The body cavity is true coelom. Phylum — Chordata · Presence of notochord dorsal hollow spinal cord —nerve cord and paired pharyngeal gill slits · Bilaterally symmetrical and triploblastic · Coelomate organ system level of organization · Have post and tail · Closed circulatory system Chordates Non chordates 1. They are i Non-chordata absence of notochord ii Chordata presence of notochord They can also be classified on the basis of presence or absence of vertebral column backbone into i Invertebrates without backbone ii Vertebrates with backbone The Non-chordata includes the following phylums hPhylum Porifera Phylum—Porifera Porous — pore; ferre — to bear includes the first and the most primitive group of multicellular animals, referred to as poriferans, i. Inhabit estuaries and coastal sea. Digestion In coelenteron or gastrovascular cavity, both intracellular and extracellular digestion occurs.
Fertilisation is external and development is indirect, e. Symmetrical The body of some animals can be divided into two similar equal halves by one or more planes. Habit and Habitat Majority of forms are parasitic tapeworms, liver flukes, blood flukes , etc. Choose correctly and write in the space provided. Students can visit the links mentioned below to know more about this chapter. Body Cavity They have true coelom, which is lined by a ciliated peritoneum. Phylum - Porifera - Ex.
Life cycle is simple or complicated. Therefore, there are more chances of their survival and hence, less number of young ones is produced compared to the number of eggs. Subphylum — Vertebrata — In this subphylum, the vertebral column is mainly replaced by and includes a well-developed head. Streamlined body with four pair of gills covered by operculum. These vast species have diverse structural forms.
Class — Osteichthyes - boney fish · Endoskeleton is bone. The two layers are; ectoderm and endoderm. Sucking and circular mouth without jaws. Classification of Protozoa Class 1. Question 14: Match the following: Answer Question 15: Prepare a list of some animals that are found parasitic on human beings. They are triploblastic, coelomate, bilaterally symmetrical with chitinous exoskeleton. Cellular level organization is present in unicellular animals and some of the muclticellular animals.