General Features of Kingdom Animalia

Syllabus and Learning Objectives

• The chapter "Diversity Among Animals The Kingdom in Melee" is included in the PMC MDCAT 2021 syllabus.
• Learning Objectives imply what should be known for the exam from the syllabus.
• Important: Understanding the general characteristics and classification of animal phyla.
• The syllabus includes the general features of animals, which are separately given in the Federal Board book.

Kingdom Animalia - Basic Information

• The word Animal is derived from Anima (Soul)
• The Animal Kingdom includes all animals around the world.
• Animal Cell: Bound by a cell membrane, no cell wall.
• Heterotrophs are capable of creating proteins but do so by consuming other organisms.

Kingdom Animalia - Features

General Characteristics

• Eukaryotic and multicellular
• Found in all types of habitats (forests, deserts, water, underground)
• Can be both free-living and parasitic
• Both mobile (cheetah) and sessile (sea urchin) forms exist.
• Range from microscopic to blue whale (the largest animal)
• Soft-bodied (mollusks) and hard-bodied animals (armored animals)
• Organization: Tissues, Organs, Systems
• Symmetry: Asymmetrical, Radial Symmetry, Bilateral Symmetry
• Gastrula Organization: Diploblastic, Triploblastic
• Body Cavity: Acoelomate, Pseudocoelomate, True Coelomate

Reproduction

• Asexual (budding, fragmentation) and sexual reproduction
• Most animals possess both asexual and sexual reproduction methods.
• Development can be direct or indirect (including larval stages)

Animal Groups

Porifera

• Radial symmetry, sessile and sea sponges
• Body includes osculum and ostia (small pores)
• Cellular organization
• Body cavity (spongocoel)
• Skeleton made of calcium carbonate

Cnidaria

• Radial symmetry, aquatic (mostly marine)
• Polyp and medusa phases
• Gastrovascular cavity (celenteron)
• Tentacles containing nematocysts
• Asexual budding, sexual reproduction (gonads)

Platyhelminthes

• Flatworms, lack of body cavity
• Acoelomate, triploblastic
• Some are parasitic (human intestines)

Nematoda

• Roundworms, body cavity pseudocoelomate
• Parasites and free-living

Classification of Animalia

Fish

• Chondrichthyes: Cartilaginous skeleton, paired fins
• Osteichthyes: Bony fish, lobe fins

Amphibians

• Divided life (water and land)
• Without scales and hair, soft and moist skin
• Three-chambered heart, larval stage fish-like (tadpole)
• Oviparous and metamorphosis

Reptiles

• Reptilian animals, scaled skin
• Land-living vertebrates, adapt to cold climates
• Incomplete four-chambered heart, leathery shelled eggs

Aves (Birds)

• Feathers and homeothermic
• Adapted for flight, true four-chambered heart
• Oviparous, large amount of yolk in eggs

Mammalia

• Warm-blooded, presence of mammary glands, diaphragm, complex brain
• Homeotherms, externally visible pinna
• Prototheria (egg-laying), Metatheria (pouched), Eutheria (placental mammals)