Biology Human Biology

1. Biology Human Biology

2. Biology is concerned with life phenomena of every kind and nature. Biology is the study of living things . Biology is a science of life concerned with the study of life and living organisms, including their structure, function, growth, origin, evolution, distribution, and taxonomy.  

3. Biology is concerned with the study of the interrelationship of organisms and evolution of life. biology (from the Greek words bios, life, and logos, word thought) is the study of living organisms and life’s processes. It is the study of life. Other branches of science are chemistry, physics, geology, astronomy, and related fields such as medicine.

4. There are many branches of biology ,every one is study of a group of organisms or special field of life that Zoology , Botany , Cytology , Ecology, Genetics, Anatomy, Microbiology (Parasitology , Virology , Bactriology , Immunology) ,Taxonomy , Physiology ,Embryology, Molecular biology ,Biotechnology ,Bioengineering …..

5. All living organisms share some basic characteristics: 1. Order: a) An organism is highly ordered with cells, tissues, organs, etc b) The biosphere is highly ordered in terms of the lower levels. c) Individual structures, like compound eyes, show distinct organization.

6. 2. Response to Stimuli: a) Interaction with the environment and other living organisms. b) Responses help ensure survival. c) Activities in response to stimuli are termed behaviors.

7. 3. Regulation of Internal Environment a) Organisms must maintain a state of biological balance b) Homeostasis is the balance maintained regarding temperature, moisture, acidity, and other physiological factors. c) Organisms have feedback and control mechanisms that do not require conscious activity . d) Through behavior, organisms can also maintain homeostasis

8. 4. Acquisition of Materials and Energy: a) Living organisms require an outside source of nutrients and energy. b) Energy is the capacity to do work. It can be gained from food intake. c) Metabolism is the sum of all chemical reactions that occur in a cell. d) Energy is required to ensure that metabolism can occur. e) The sun is the ultimate source of all energy on Earth. f) Photosynthesis transforms solar energy into chemical energy in the form organic molecules in plants. g) All life acquires energy by metabolizing the products of photosynthesis.

9. 5. Reproduction and Development: a) Life comes only from life. b) An organism can reproduce or make more organisms like it. 6. Genetic Inheritance a) The blueprint for an organism is encoded in the genes of DNA. b) Genes contain specific information for how the organism is to be ordered c) DNA (deoxyribonucleic acid) is the genetic code in all living things.

10. 7. Evolutionary Adaptations: a) Adaptations are modifications that make organisms suited to their life. b) Adaptations come about through evolution c)Evolution is the process by which a species changes over time. d) A species is a group of similar organisms that can interbreed.

11. e) Modifications occur over time as organisms reproduce. f)Natural selection, proposed by Charles Darwin, explains how species change over time when a new variation arises that allows certain members to be more competitive and thus survive and reproduce better. g) The theory of evolution can explain the diversity of life

12. All living things share certain key characteristics: order, sensitivity, growth, development and reproduction, regulation, and homeostasis.

13. Basic Principles of Biology The foundation of biologist exists today is based on five basic principles. basic theories are present in biology 1-Cell Theory: all living organisms are composed of cells. The cell is the basic unit of life. 2-Gene Theory: traits are inherited through gene transmission. Genesare located on chromosomesand consist ofDNA. 3-Evolution: any genetic change in a population that is inherited over several generations. These changes may be small or large, noticeable or not so noticeable.

14. Basic Principles of Biology • 4-Homeostasis: ability to maintain a constant internal environment in response to environmental changes. 5-Thermodynamics: energy is constant and energy transformation is not completely efficient. • 6-The Ecosystem Theory: organisms are members of populations that interact with each other and with the physical environment within a particular locale

15. Importance of Scientific Theories in Biology Scientific theories are concepts that tell us about the order and the patterns within the natural world—in other words, how the natural world is organized

16. following are some of the basic theories of biology

17. Medical biology :is a field of biology that has practical application in medicine ,health care and laboratory diagnostics Human Biology introduces students to the anatomy and physiology of the human body Human biology can be studied on any level of biological organization

18. Life has many levels of organization A.All forms of life are organized similarly B.There are some levels of biological organization. 1-The chemical organization ( Atoms: – Smallest unit of an element containing electrons, protons, neutrons and molecules ( union of two or more atoms) 2-The cellular organization( Basic unit of structure and function of all living things). 3-The tissue level of organization( Group of cells with a common structural function). 4-The organ level of organization(Structure composed of tissues with similar function ). 5- The system level of organization (Composed of several organs working together ) .

19. 6- The organism level of organization (An individual). 7- The ecological level of organization :that including a-Populations –– All organisms of one species that live in a particular area. b- Communities – Interacting populations in a particular area.- c-Ecosystems –A community and the physical environment around it. d-Biosphere: –The sum of all of Earth’s ecosystems, the most complex level. d C. Complexity increases with each level from atom to biosphere. D. Each increase in complexity is associated with the establishment of properties beyond those of the previous level. This is known as emergent properties.

23. The Cell The Tissues Histology

24. The cell is the smallest biological unit. It is the structural and functional unit of all living forms; unicellular and multicellular organisms. • Cytology: (Cytos means cell; ology means science) is the branch of biology that studies the basic structure, function and chemistry of cells or the biological science which deals with the study of structure, function, molecular organization, growth, reproduction and genetics of the cells • cytology: study of cell structure by light microscopy

25. Cell Theory The cell theory is an end-result of the works of botanist Matthias Schleiden(1838), Zoologist Theodor Schwann (1839) and physician Rudolph Virchow (1855). The cell theory is a unifying concept that says that: The cell is the basic structural and functional unit of life forms in unicellular or multicellular organisms. They are characterized by: 1- The cells come from other cells. 2- The cells are similar in structure. 3-The cells are modified to in a variety of ways to carry out specialized function. 4-The cells are variable in shape. 5- Cell size is limited and most cells are microscopic.

26. Differences between prokaryotic and eukaryotic cells

29. differencesThe cells of animals and plants have the following

30. Structure of the Cell and Cell Organelles: Although the cells are variable in their shapes, sizes and functions, they are well organized structures and usually contain the same components .Cell structure reflects cell function. • Most cells are small and can be seen only under a microscope .The small size of cells means that they are measured using the smaller units of the metric system, such as the micrometer (μm). A micrometer is 1/1,000 millimeter.

31. Basic Structure:Examination of a cell by light microscopy shows a fluid cell body (cytoplasm),a cell nucleus and the surrounding cell membrane (plasmalemma) The cytoplasm contains a number of highlyorganized small bodies, called cell organelles, that can often only beseen by electron microscopy. It also contains certain supportive structures(parts of the cytoskeleton) and numerous cell inclusions (e. g., metabolicsubstrates and end products)

32. Theplasma membrane( Plasmalemma or cell membrane) that surrounds and keeps the cell intact regulates what enters and exits a cell. The plasma membrane is a phospholipidbilayer that is said to be semipermeable because it allows certain molecules but not others to enter the cell. Proteins present in the plasma membrane play important roles in allowing substances to enter the cell.

37. Transport between cells and there surroundings Molecules (and ions) cross the plasma membrane in three major ways: (1) passive transport (diffusion , osmosis andfacilitated transport), (2) active transport (3) endocytosis or exocytosis

38. 1-1 -Diffusion :Is the random movement of molecules from an area of higher concentration to an area of lower concentration, until they are equally distributed. Diffusion is a passive way for molecules to enter or exit a cell. No cellular energy is needed to bring it about.

39. Dialysis :It is the process of diffusion of a solute (dissolved substances) across a selectively permeable membrane (such as hemodialysisand peritoneal dialysis). It is used for separation of substances in solution by means of their unequal diffusion through semi-permeable membrane Hemodialysis; dialysis of the blood is used to remove toxic substance or metabolic wastes from blood stream in case of kidney failure

40. 1-2-Osmosis: Is the net movement of water across a semipermeable membrane, from an area of higher concentration to an area of lower concentration. The membrane separates the two areas, and solute is unable to pass through the membrane. • Water will tend to fl ow from the area that has less solute (and therefore more water) to the area with more solute(and therefore less water).

42. 1-3-Facilitated Transport: Many solutes do not simply diffuse across a plasma membrane . They are transported by means of protein carriers within themembrane. During facilitated transport,a molecule is transportedacross the plasma membrane from the side of higherconcentration to the side of lower concentration

43. 2-Active Transport: During active transport, a molecule is moving from a lower to higher concentration • Active transport requires a protein carrier and the useof cellular energy obtained from the breakdown of ATP • The energy is used to carry out active transport. Proteins involved in active transport often are called pumps

44. Selective permeability of the plasma membrane

45. 3-EndocytosisandExocytosis: These two processes are based on the same principle but have different directions of movement. Endocytosismoves materials into the cell, and exocytosis moves materials out of the cell.

47. Overveiw of plasma membrane transport

48. Nutrition Nutrition: You are what you eat

49. Nutrition: Some people eat to live, but many others seem to live to eat. food probably occupies a central part of your life. Nutrition is the interaction between an organism and its food. Because nearly all nutrients enter the body through the digestive system. The nutrients we need to survive and prosper physically and mentally can be divided into two broad categories: 1-macronutrients such as water, amino acid ,protein ,lipid and carbohydrates 2-micronutrients such as vitamin and minerals

50. Before going into more detail about the individual nutrients we can summarize their functions as follows: 1-Carbohydrates : such as sugars starch , supply energy . Carbohydrates are a group of organic compounds. It includes such well-known examples as table sugar (sucrose), blood sugar (glucose), and starch. Carbohydrates consist primarily of carbon, oxygen, and hydrogen.