Chp 1 Zoology as Biological Science

• Biology is the science of living things, including their structure, function, interaction, and change or evolution.
• Zoology, the study of animals, is a science under Biology together with botany, the study of plants, and microbiology, the study of microorganisms.
• Organisms are highly organized, coordinated structures that consist of one or more cells.
• Unicellular organisms have no higher organization than colonies.
• Multicellular organisms have individual organisms, systems, organs, tissues, and cells.
• Organisms respond to diverse stimuli, such as chemotaxis and phototaxis.
• Organisms reproduce, with single-celled organisms duplicating their DNA and dividing it equally as the cell prepares to divide to form two new cells.
• Multicellular organisms often produce specialized reproductive germline cells that will form new individuals.
• When reproduction occurs, genes containing DNA are passed along to an organism’s offspring, ensuring that the offspring will belong to the same species and will have similar characteristics, such as size and shape.
• Sexual reproduction involves both male and female parents, while asexual reproduction involves one parent.
• Types of asexual reproduction include fragmentation, budding, binary fission, regeneration, spore formation, parthenogenesis, and sporulation.
• Organisms grow and develop following specific instructions coded for by their genes.
• Unicellular organisms undergo continuous cell division, increasing in cell number, while multicellular organisms undergo cell division then the level of organization grows and develops in function, a process known as maturing.
• To coordinate internal functions, respond to stimuli, and cope with environmental stresses, organisms require multiple regulatory mechanisms, such as the internal functions regulated in an organism are nutrient transport and blood flow.
• Homeostasis is the ability of an organism to maintain constant internal conditions.
• Thermoregulation is a process to regulate body temperature.
• All organisms use a source of energy for their metabolic activities, such as photosynthesis and cellular respiration.
• Living systems are objects with definite boundaries, continually exchanging some materials with their surroundings but without altering their general properties, at least over some period of time.
• The sum of the total of all chemical reactions of the body is known as metabolic rate.
• Life is defined as any system capable of performing functions such as eating, metabolizing, excreting, breathing, moving, growing, reproducing, and responding to external stimuli.
• Living organisms as systems that contain reproducible hereditary information coded in nucleic acid molecules and that metabolize by controlling the rate of chemical reactions using the proteinaceous catalysts known as enzymes are known as biochemical organisms.
• Ribonucleic acid (RNA) molecules may replicate, mutate, and then replicate their mutations in test tubes.
• A genetic definition of life would be a system capable of evolution by natural selection.
• Mutation refers to the imperfections in gene replication.
• Replication refers to the capacity of molecules such as deoxyribonucleic acid (DNA) to precisely copy themselves, whereas reproduction refers to the increase in the number of organisms by acts that make a new individual from its parent or parents.
• Thermodynamic distinguishes between isolated, closed, and open systems.
• Isolated system is separated from the rest of the environment and exchanges neither light nor heat nor matter with its surroundings.
• Closed system exchanges energy but not matter.
• Open system both material and energetic exchanges occur.
• The second law of thermodynamics states that in a closed system, no processes will tend to occur that increase the net organization (or decrease the net entropy) of the system.
• Chemoautotrophs obtain their energy from chemical (inorganic or organic).
• Autopoietic resembles the physiological definition but emphasizes life’s maintenance of its own identity, its informational closure, its cybernetic self-relatedness, and its ability to make more of itself.
• Autopoiesis refers to self-producing, self-maintaining, self-repairing, and self-relational aspects of living systems.
• Spontaneous generation was the idea that living organisms could spring fully formed from non-living things.
• Francesco Redi, an Italian physician, performed experiments designed to test spontaneous generation.
• Anton van Leeuwenhoek, a Dutch microbiologist who invented the microscope, was the first to observe microorganisms.
• George Buffon, the first European to propose that the earth and solar system had arisen due to natural processes and that life itself had emerged from the earth, also proposed the concept of divine creation.
• John Needham boiled broth, then covered it a few days later, microorganisms grew.
• Lazzaro Spallanzani suspected that microorganisms had entered the flask through the air before Needham had sealed it and boiled it.
• Louis Pasteur demonstrated an experiment that microorganisms did not arise via spontaneous generation with his swan-necked flask.