UNIT 1: Organization and Continuity of Animal Life *The presenter invokes the principle of fair use for the use of copyrighted materials in this presentation. Unit Outline Perspectives in Zoology Animal Cell Membrane Function Cellular Respiration Cell Cycle Flow of Genetic Information Zoology: Understanding Animals Learning Outcomes discuss the evolutionary and ecological perspectives in the study of animal life; state and define at least three characteristics of animals as living systems; differentiate an animal from other eukaryotic organisms. Zoology one of the broadest scientific fields study of animals solve the mysteries and origin of animal life documenting animal diversity organizing animals in a systematic way understanding the complex processes occurring within animal organisms different subfields in zoology Zoology: An Evolutionary Perspective Animals share a common evolutionary past and evolutionary forces that influenced their history. Evolutionary processes have resulted in an estimated 4 to 10 million species of animals living today. Organic evolution is the change in the genetic makeup of populations of organisms over time. explains why animals appear and function as they do explains family relationships within the animal kingdom Degree of Relatedness Organisms in the same species are more closely related than organisms in the same genus, and organisms in the same genus are more closely related than organisms in the same family, and so on. Animal Phyla ❑ ❑ about 35 animal phyla phylogenetic tree shows how animals are related through evolution Zoology: An Ecological Perspective Ecology is the study of the relationships between organisms and their environment. Problem on global overpopulation → exploitation of world resources Threatened > vulnerable > endangered > extinct animals An understanding of basic ecological principles can help prevent ecological disasters. General Properties of Living Systems Chemical Uniqueness Living systems demonstrate a unique and complex molecular organization. macromolecules (biomolecules) carbohydrates --- C, H, O lipids --- C, H, O proteins --- C, H, O, N, S nucleic acids --- C, H, O, N, P General Properties of Living Systems Complexity and hierarchical organization biosphere ecosystem Living systems demonstrate a unique and complex hierarchical organization. community population emergent properties organism cells macromolecules in increasing complexity General Properties of Living Systems Reproduction Living systems can reproduce themselves. asexual or sexual heredity – transmission of traits variation – differences in traits General Properties of Living Systems Possession of a genetic program A genetic program provides fidelity of inheritance. genes --- segments of DNA coding for a trait central dogma of biology: DNA → RNA → protein General Properties of Living Systems Metabolism Living organisms maintain themselves by obtaining nutrients and energy from their environments. anabolic reactions --- synthesis of compounds catabolic reactions --- breakdown of compounds enzymes --- catalyze metabolic reactions physiology --- study of the performance of complex metabolic functions homeostasis --- state of internal balance maintained by feedback mechanisms General Properties of Living Systems Growth and Development All organisms pass through a characteristic life cycle. growth --- increase in number and size of cells development --- characteristic changes that an organism undergoes General Properties of Living Systems Environmental Interaction All animals interact with their environment. ecology --- understand how an organism can perceive environmental stimuli and respond in appropriate ways by adjusting its metabolism and physiology irritability responsiveness adaptation Heterotrophy Can’t make their own food… must eat things. Mobility Animals can swim, crawl, walk, run, and even fly. Some only move in the larval stage… the sponge Absence of a Cell Wall ❑ ❑ animal cells lack rigid cell walls allowed animals mobility Multicellularity Made up of more then one cell! Although animals come in a wide range of sizes, the cell sizes are all very similar! Sexual Reproduction Almost all animals reproduce sexually by producing gametes. Unlike the egg cells, the sperm cells of animals have a flagella and are highly mobile. Diploidy ❑ Adults have two copies of each chromosome, one inherited from their father and one from their mother. Blastula Formation ❑ In all animals except sponges, the fertilized egg cell (zygote) undergoes cell divisions that form a hollow ball of cells called a blastula. BREAK!
