Integrate by discussion the properties of life, basic chemical terminology, and molecules and compounds of a cell necessary for life. Include the basic anatomy and physiology of a cell and describe how cell respiration, photosynthesis and cell reproduction occur in a succinct manner. Include a brief discussion about Mendel's Laws and an overview of DNA structure and function. Conclude with a discussion of cancer and the mechanisms of gene control.
SC160.3.1 Basic Biology
Assignment 03,
General Biology
It is possible that life on other planets could be very different from what we are accustomed to on earth. But in order to look for life in the universe, or even in our Solar System, researchers must have a set of criteria by which to define what life is. Based on our current level of understanding, the best approach is to look for characteristics or traits that are common among many different living organisms. There are six properties of life that are shared by all living organisms on earth: order, reproduction, growth and development, energy utilization, response to stimuli and evolutionary adaption. Earth is a home of all living beings. There are different types of definitions to define earth. The source of different inventions or creation of every things is earth. For example, the word 'chemistry' is derived from an Egyptian term keme (chem) which means 'earth'. The study of chemistry began several thousand years ago. Chemistry is an extremely vast subject. It has several branches. Some of the important aspects of this field include: study of atomic and molecular structure of various chemical substances, their characteristics, type of reactions, type of bonds formed by different elements, methods used for extraction of metals and nonmetals, different laboratory techniques etc. Chemistry is also refer as central science as its study is essential for various other branches of Science like Physics, Biology, Geology, Astronomy, etc.
The nature of life on Earth is amazingly complex and diverse. Yet, all life on Earth is composed of the same types of molecules. For instance, all living organisms utilize the same information containing molecules, DNA, to pass on genetic information from generation to generation. Most matter in our body that is not water is made of organic compounds. Organic compounds contain carbon atoms that are covalently bonded to other elements - typically hydrogen, oxygen and other carbon atoms. The four main types of organic compounds found in living things include familiar names like carbohydrates, lipids (like fats and steroids), nucleic acids and proteins. These larger molecules create the structural parts of the cell (like phospholipids in cell membranes), carry information (like DNA in our genes), and control the rate of chemical reactions in the cells (like enzymes). Without these compounds, cells could not function. Water, oxygen, carbon dioxide and the minerals needed to sustain life are inorganic. Body composition may also be analyzed in terms of molecular types.
Anatomy is the study of the body's internal and external structure and the physical relationships between the body's constituent parts and Physiology is the study of how these parts work. Anatomy and Physiology make up the entire framework of a human body. Anatomy and Physiology are inseparable: one cannot function without the other. Function and structure affect each other simultaneously. Cellular respiration and photosynthesis are the two main processes performed by most living organisms to obtain usable energy from nature. While photosynthesis is performed by most plants who can prepare their own food, most animals fulfill their energy requirements through cellular respiration. Photosynthesis takes place in the cells of pant leaves in structure called chloroplasts, which contain chlorophyll. The plant cells absorb light from the sun through the chlorophyll pigment and using water and carbon dioxide obtained from the environment, undergo a series of chemical reactions to produce carbohydrate molecules. Similarly, cellular respiration takes place in the same way in both plants and animals. Living cells obtain the products of photosynthesis (sugar molecules) and undergo cellular respiration to produce ATP molecules. Some cells respire aerobically, using oxygen, while others undergo anaerobic respiration, without using oxygen. The process involves a set of chemical reactions to convert chemical energy from glucose molecules into ATP molecules. Cell divisions is a process by which a parent cell divides into two or more daughter cells or when a cell undergoes reproduction, or cell division, the two 'daughter' cells that result are genetically identical to each other and to the original 'parent' cell. Before the parent cell splits into two, it duplicates its chromosomes, the structures that contain most of the cell's DNA. Then, during the division process, one set of chromosomes is distributed to each daughter cell. Each daughter cell receives identical sets of chromosomes from the lone, original parent cell. In shortly, cellular reproduction is a means of creating new life.
Genetics is the study of genes, heredity and variation in living organisms. It is generally considered a field of biology, but it intersects frequently with many of the life sciences and is strongly linked with the study of information systems. The father of genetics is Gregor Mendel, a scientist and Augustinian friar. George Mendel, through his work on pea plants, discovered the fundamental laws of inheritance. He deduced that genes come in pairs and are inherited as distinct units, one from each parent. Mendel tracked the segregation of parental genes and their appearance in the offspring as dominant or recessive traits. He recognized the mathematical patterns of inheritance from one generation to the next. Mendel's Laws of heredity are usually stated as: The Law of Segregation, The Law of Independent Assortment and The Law of Dominance. DNA is also one main components of genetics. DNA (DeoxyriboNucleic Acid) is an extremely (by cellular standards) long macromolecule which forms the main component of chromosomes (a basic component in the genetic determination and development of all known life forms). DNA, structurally, is composed of two nucleotide 'strands', which coil around each other like a set of spiraling stair cases. It is constructed of two main chains of alternating phosphate and deoxyribose units, bound together chemically with purine and pyrimidine bases and the functions are vital for inheritance, coding for proteins and the genetic blueprint of life. Given the enormity of DNA's functions in the human body and its responsibility for the growth and maintenance of life, it is not surprising that the discovery of DNA has led to such a great number of development and reproduction - ultimately, its survival.
Today's one of the most dangerous diseases is cancer. It is a disease of cells in the body. Cancer develops when a cell becomes abnormal and begins to grow out of control. Cancer can begin when mutation changes a cell's DNA sequence. But cancer cells also have abnormal epigenomes. In many cancers, some genes are turned up and some are turned down - often in the very same cells. Cancer is just one of a growing number of diseases that are being linked to abnormalities in the epigenome and out of control growth leads to cancer by both turning off genes coding for proteins that speed up cell growth. Cancer cells have a lower level of methylation (more active DNA) than healthy cells and genes that have more methyl (are less active) than normal. At last, biology is a natural science concerned with the study of life and living organisms, including their structure, function, growth, evolution, distribution and taxonomy.
References
Enger, Eldon D. & Ross, (2003). Concepts in Biology (10th Ed). New York: McGraw-Hill.
Krap & Gerald, (2008). Cell and Molecular Biology (5th Ed). New Jersey: Wiley.
Eric J. Simon, Jean L. Dickey & Jane B. Reece, (2013). Essential Biology (5th Ed). London: Pearson.
