help with biology homework

help with biology homework

The Fascinating World of Biology: A Comprehensive Guide

1. Introduction to Biology

In case the earth is ever destroyed, one day in the distant future, alien beings would be able to reconstruct much about us by studying a biology book. The complex relationships among all living things on earth make biology an endlessly fascinating subject to study. Biology gives us detailed information on how living organisms function, more specifically, how structure is related to the function of living things. Animals and plants show the greatest anatomical and physiological differences, and yet, they share a close and fascinating molecular connection. The intricate DNA decoded structures of animal and human genetic material are strikingly similar to the DNA decoded structures of the genetic materials of a host of microscopic organisms, like bacteria and wheat. With the tremendous advances that science has recently made in molecular biology, in particular in DNA technology, biologists can examine the relationships between species with impressive accuracy. Through DNA studies, it is now possible to demonstrate beyond a shadow of a doubt that all living organisms on earth are linked.

Biology is the science of life. All living things share certain life processes such as growth, reproduction, and maintaining a stable internal environment. The study of biology explores these processes at many levels, from the very small workings of tiny organelles to cells (the basic units of structure and function of all living things), to the extremely complex biological systems of the human body and the conversion of multiple individual organisms to populations and their community interactions. The presentations provided with this teaching guide are designed to allow students to explore a variety of selections. Information is designed to open the student to new realms of biology, no matter their current learning level. This guide is appropriate for all students studying biology, from grade 10 to grade 14, and is designed for individual and team use.

2. Cell Biology: The Building Blocks of Life

The rare exceptions are some ‘unicellular’ fungi and algae, and all plants and animals. These exceptions emphasize the principle that organisms have evolved many solutions to similar problems during the course of life on earth. Plants, fungi and animals solve the problems of such complex processes as obtaining nutrients from the environment, perception of and reaction to other organisms, movement, and reproduction with significantly different cell types. Additionally, cells may be directly associated from birth as budding occurs in some unicellular organisms. Because many cells capable of independent living are not physically or biochemically attached to one another, multicellularity necessarily requires significant molecular and biochemical organization and cooperation within individual cells, and dependably timed division and separation of specialized cells for specific lineage commitment. While treating the question of cellular cooperation in the evolution of multicellularity, part of this chapter will clarify the remarkable differences between single nucleated cells surrounded by a nonswing membrane vs. a mixed relationship of nucleus to cytoplasm in the multinucleated cells that comprise the majority of organisms on earth.

Cells are tiny structures, usually many times smaller than what we can see without a microscope. Human brains are far from understanding the details of this universe in little cells that construct it. Although there are exceptions to every rule, cells can be approximately classified into two types. The defining limitation comes whenever the exceptions to this rule are very small or very rare. Remarkably, almost all cell types of multicellular organisms fall distinctly into one of two classes on the basis of whether they have a discrete nucleus (a nuclear envelope) that encloses their genetic material, the DNA. Although most cells with nuclei come as single cells, there are many cases where units of small cells divide in unison and adhere to one another; we call the result a colony. Thus, many organisms, including fungi, plants and animals, can be built from two fundamentally different cellular organizations, single nucleus cells vs. a colony of unit nucleated cells.

3. Genetics and Heredity: The Blueprint of Life

The passing on the genetic information of living things to the next generation, i.e. heredity, means a series of characteristics in an orderly manner from the parents to the offspring. These characters define the structures (frames) of living things (phenotypes). It is a known fact that living things look like one another (parents and offspring resemble one another) because of this order. Every living thing possesses different characteristics from another of its kind. These different cells and different organs of living things are derived from specialized cells. The inheritance that carries the required information to the next generation is in the nucleus of the germ cells. The set of genetic rules that determine the characteristics of the living organism in these cells is called the genome. In other words, the genome is the genetic blueprint of living organisms. All the characteristics of living organisms are coded in the genes within the genome. These characteristics can be either different from one generation to another or identical. For instance, all the characteristics of the parents are repeated in their offspring. The genetic variation observed between the offspring and parents is considered as the expression of the unique rules that govern inheritance, the interactions of the genotypes with the environment, and of the genes harboring variation that had appeared as a result of mutation, altered recombination patterns, or other evolutionary processes. All of these genetic processes occurring in living organisms from the first unicellular organism to the most complex living mammals are encompassed within the field of heredity. In short, genetics opens the door to the mystery of the inheritance of living cells!

Genetics, which was first studied by Mendel, is the science that consists of the heredity and variation of characters inherited and passed from generation to generation in living things. Genetics deals with the basic rules of inheritance (heredity) in all living things, i.e. genes and chromosomes. The transmission of these characteristics from generation to generation, meaning passing information on to the next generations, is accomplished through the genes that are located in chromosomes. The information (inheritance) about the characteristics, structure, the rules of law, and functioning of living things is encoded in the DNA (deoxyribonucleic acid) molecules of those living things. In the transmission (sharing) of this information to the next generations, no mistakes are made over many generations and, as a result, all the characteristics continue to be repeated over and over with the same perfection.

4. Evolution: The Unifying Principle of Biology

Darwin’s fundamental contributions were the recognition of the struggle for existence, a struggle not just within living organisms for control of resources, but between organisms. He realized that there were limits to the modification of a character and that these limits would prevent the remorseless pressure of natural selection from driving the modifications of a continuous character or structure into endless improvement. The tragedy of the world lay between the inadequacies of individuals and the effects of inexorable pressures upon them. Since 1859, collective biological knowledge has filled in some of the details of Darwin’s theory, and relevant areas of the second major theory of modern biology, the theory of genes, have been enunciated.

Evolution is the unifying principle of biology. It sets life on Earth in context and explains much of the richness of the living world. Adaptations – the connection between form and function – and diversity have, singly and severally, fascinated laymen and scientists throughout biological history. For a long time, particularistic knowledge of biology developed. Taxonomists described the living world, anatomists gave us detailed knowledge of its bodily form. Evolutionary biologists have sought to give biology a coherence based on common ancestry and common struggle. Evolutionary principles, added to a particularistic knowledge of living forms, have revealed special adaptation and homology in complex bodily devices, the complexity of relationships and communication, and broader insights into the nature of life and its processes, making it a science broader than any other.

5. Ecology and Environmental Biology: Understanding Ecosystems

Ecosystems are collections of living and nonliving organisms existing and transitioning in a habitat. Biological and environmental scientists believe that an ecosystem model is the most productive way to study, learn, and understand our environment. By studying the components and complex codependence of all living and nonliving things, we can gain a better grasp of earth science and make reasonable decisions based on their interactions. Forests, grasslands, wetlands, seashores, sand dunes, or desert lands are all considered different habitat ecosystems. Each has its own group of biotic or abiotic members. A small ravine is an example of a small ecosystem, while the great Amazon forest is an example of a large-scale ecosystem. When humans interact with the components of an ecosystem, such as direct use by hiking, camping, or cutting trees, environmentalists believe that people should also be thoughtful of the area’s sustainability and long-term health.

Would you like to help save the environment and its beautiful habitats and ecosystems? Then you can do your part by understanding what makes the theories come alive. By learning what makes life sustainable and what makes it thrive, understanding ecology will give you a better idea of how to accomplish this long-term goal. If you are interested in how all of the living and nonliving things act and interact in one particular area, then the scientific discipline of ecology certainly interests you. The “birds and the bees” of different types of creatures, as well as the microorganisms that all interact in a certain space and time, are all included in the study of ecology. These interacting organisms have important context that can help ascertain the habitat’s good health. Plants and animals are considered the biotic living organisms, while the water, wind, rocks, soil, light, and humidity are considered nonliving abiotic organisms.