HUMAN BIOLOGY Lecture Notes PDF

3/26/2022 Biology (from Greek bios “life"; logia, study of) HUMAN BIOLOGY Biology:- Is study of living organisms and how they interact w...

3/26/2022 Biology (from Greek bios “life"; logia, study of) HUMAN BIOLOGY Biology:- Is study of living organisms and how they interact with each other and with INTRODUCTION their environment. Biology examines structure, function, growth, taxonomy, origin, evolution, and distribution of living things. Biology and medicine Biology and medicine Biological knowledge is used in:- The most direct impact of biology on our Stopping infectious diseases lives is in medicine ,where scientific advances are improving health and health Flu, tuberculosis, malaria. care every day. Curing genetic disorders Cystic fibrosis ,muscular dystrophy. Study earth ability to sustain the human population which being strained. 1  3/26/2022 The characteristics of life All living organisms share basic characteristics. Biology They are: (1) organized (2) acquire materials and energy How to define life (3) homeostatic (4) respond to stimuli (5) reproduce and grow (6) have an evolutionary history. Organization Organization Living things are highly organize, from the smallest part to the largest one. The smallest part of an organism is a cell. Single-celled organisms are free-living and contain There are levels of biological organization that structures, called organelles, which allow them to be self- extend beyond the individual organism.All the sufficient. Higher organisms are multi cellular, In which, members of one species in a particular area belong cells are organize into tissues. These have a common to population.The population of various animals function like muscle.Tissues are organize into organs like and plant make a community.The community of the heart. Organs are organize into organ system, like the populations interacts with physical environment cardiovascular system. Organ systems functioning together make up a living organism. and forms an ecosystem.Finally , all the earth’s ecosystems make up the biosphere. 2  3/26/2022 Acquire materials and energy All organisms require energy to carryout life processes, like grow and do work. Almost all the energy on earth is obtained from the sun.Plants capture the energy of sunlight and use it to make complex molecules (glucose) in process called photosynthesis. This molecules then serve as the source of fuel for animals that eat them. Living Organisms Respond Homeostasis The ability of a cell or an organism to Homeostasis would be impossible maintain an internal environment that without the body’s ability to respond operates under specific conditions is called to stimuli. Response to external homeostasis. In humans, many of organ stimuli is more apparent to us, systems work to maintain homeostasis. For because it involves movement, as example, human body temperature when we quickly remove a hand from normally fluctuates slightly between 36.5 and 37.5° a hot stove. 3  3/26/2022 Evolution Reproduce and development Evolution is the process by which a population All living organisms can reproduce ,or make copies changes over time. like themselves.Bacteria for example ,and other The mechanism by which evolution occurs is natural selection. When a new variation arises that allows unicellular organisms are simply split in two. certain members of a population to capture more The reproductive process ,in multi cellular organisms resources, these members tend to survive and have , begin with pairing of a sperm from one partner and more offspring than the other, unchanged members. an egg from the other partner. This union follow by Therefore, each successive generation will include many cell division ,results in an immature individual more members with the new variation, which represents an adaptation to the environment. ,which grows and develops through various stages to become an adult organism. classification of living organisms Linnaean system Carolus Linnaeus (1735) Living organisms are classified in a variety of ways. This help scientists to study the In 1735, Linnaeus published an relationships between living organism important book entitled Systema groups ,and to see the whole Naturae in which he classified all family tree of living organisms as it has developed through time. The study of living known organisms, and developed the organisms classification is called taxonomy. system of binomial nomenclature. 4  3/26/2022 Linnaean system Binomial nomenclature "two names" levels of classification The Linnaean classification system use two Latin name Kingdom categories, genus and specie. First name is genus second Phylum name is species. Scientific name:- Class It always write in italic or with an under line (genus is Order capital and species name is lower case). For example the Family scientific name of human is Genus Homo sapiens Homo sapiens Species Domain of life Domain of life Living organisms are classified into three Domain Eukarya is divided into one of four domains. domain Bacteria and domain Archaea, kingdoms plants (Plantae), fungi (Fungi), animals contain prokaryotes, single-celled organisms that (Animalia), and protists (Protista). Most lack a nucleus. third domain, Eukarya, contain organisms in kingdom Animalia are invertebrates, such as earthworms, insects, and mollusks. organisms with cells that possess a nucleus. Some Vertebrates are animals that have a nerve cord of these organisms are single-celled; others are protected by a vertebral column, which gives multicellular. Humans are multicelled Eukarya. them their name. Fish, reptiles, amphibians, and birds are all vertebrates. 5  3/26/2022 Investigation a problem Kingdom Types of Organisms Scientific method Monera bacteria, blue-green algae, and spirochetes Protista protozoan and algae of various types An important characteristic of science is using an organized approach to solve Fungi funguses, molds, mushrooms, yeasts problems. The steps of investigating a problem are: mosses, ferns, woody and non-woody Plantae (plants) flowering plants sponges, worms, insects, fish, amphibians, Animalia (animals) reptiles, birds, and mammals Investigating a problem Making Observations Making an observations The starting point is always an observation. You Forming a hypothesis (A hypothesis is an idea to work from) might observe something unusual or something Researching ( reading literature to give you a background or very common. information that already exists concerning your hypothesis) The second step is recognition (understanding) of Prediction problem. After making a few preliminary An experiment ( tests the prediction that made by hypothesis) (introductory) observation, you may have a Collecting data (Data means all measurements and observations from a controlled experiment) question about the observation. Most often it takes Conclusions (Reporting results) shape as a “how” or “why” question. 6  3/26/2022 Forming a Hypothesis Criteria of hypothesis A hypothesis (assumption) is an idea to work from, it is a preliminary explanation to a problem. It must suggest a cause –and-effect relationship A scientific hypothesis has an important role in problem solving. It is used to make predictions that can tested. It must have only one causative agent Often a scientist will develop several hypothesis related to a (factor) or variable at a time. single problem, that mean the same hypothesis may be revised It must be testable (The variable suggested in light of new information. in the hypothesis must be subject to Hypothesis are often made in a form called an “If…….. experimentation) Then…….” statement. The prediction is the second part of the statement. Experiment Collecting data An experiment isolates a single factor that is directly responsible for an effect for example, you are When doing an experiment, you might collect and write investigating whether or not a particular medicine down information. For example(You might track the prevents infection. Your hypothesis might be stated as differences in bacterial growth. You might measure the follows: “If the medicine prevents infection, then the size of the clear ring around the disk to compare it with medicine will prevent the growth of bacteria that cause the ring from the another medicine). All measurements the infection” and observation from controlled experiments are called data and are recorded whether or not they support the hypothesis. The data are then analyzed to form conclusions. 7  3/26/2022 Conclusion Critical Thinking If the data support the hypothesis, then the hypothesis is accepted. If the data do not support the hypothesis ,then the hypothesis critical thinking using systematic, objective is rejected. As long as an experiment is strategies, to judge the quality of information; well designed and executed (carried out, some times called evidence-based thinking. done), the experiment is still valid(correct) even when the hypothesis is rejected. 8