BSC 2011 Exam 1 Dixon Lecture 1 Key Concepts Be able to explain how development genetics evolution and ecology relate to the diversity of life structures individuals species etc Biology s core theme is evolution the idea that the organisms of living on earth today are modified descendants of common ancestors Development and genetics tie in with evolution and ecology which relate to the diversity of life because any slight altercation of genetics evolution and ecology defies the diversity of how the species will develop The hierarchy of life follows as biosphere ecosystem community population organism organ system organ tissue cell organelle molecule atom Be able to describe some of the fundamental properties of life Species are classified into broader groups known as Bacteria Archea and Eukarya There are 7 fundamental properties of life 1 Complexity and organization all life replicated through DNA and RNA all life is composed of cells 2 Ability to respond to stimuli 3 Exhibit homeostasis regulate body processes 4 Acquisition and use of material and energy e g sunlight to sugar 5 Growth 6 Reproduction 7 Capacity to evolve Begin to use the scientific method Scientific method is a method of procedure consisting in systematic observation measurement and experiment and the formulation testing and modification of hypotheses Terminology Biosphere all life on earth and all places life exists Ecosystem consists of all the living things in a particular area along with all nonliving components of the environment with which life interacts All ecosystems combined make up the biosphere Community the entire array of organisms inhabiting a particular ecosystem is called a biological community Population a population consists of all the individuals of a species living within the bounds of a specified area Organisms individual living things Organs and organ system an organ is a body part that carries out a particular function in the body such as the maple leaf of a tree or the heart of a human Tissues made up of a group of cells that work together performing a specialized function Cells the fundamental unit of structure and function Organelles the various functional components in cells such as a Molecule a molecule is a chemical structure consisting have 2 or smaller chloroplast or mitochondria chemical units called atoms Feedback mechanisms the most common form in organisms is negative feedback negative feedback is the accumulation of an end product of a process slows that process For example the cell s breakdown of sugar generates chemical energy in the form of ATP Positive feedback is when the end product speeds up its own production for example the clotting of your own blood in response to an injury Evolution the idea that the organisms of living on earth today are modified descendants of common ancestors Inquiry a search for information and explanation Hypothesis a tentative answer to a well framed question an explanation on trial Experiment a scientific procedure undertaken to make a discovery test a hypothesis or demonstrate a known fact Independent variable a variable often denoted by x whose variation does not depend on that of another Dependent variable a variable often denoted by y whose value depends on that of another Lecture 2 Concepts Be able to explain why cells are considered living things and subcellular structures are not considered living using the properties of living things Cells are considered living things because they all the basic structures of life within the cell in order to operate while subcellular structures such as mitochondria is not considered alive because it can not operate on its own Know that DNA is organized into structures called chromosomes Be able to explain why the chromatin in chromosomes can coil up to form a compact structure for the purpose of cell division The coiling allows the chromatids to become sorted which allows them to Know the multiple functions of cell division be separated Reproduction Growth Repair Know that cell division results in genetically identical daughter cells Be able to describe the structure of a eukaryotic chromosome A non dividing chromosome is composed of a strand of DNA wound around protein molecules called histones The DNA will have a series of genes within the chromosome Be able to diagram the cell cycle and distinguish the processes of DNA Mitosis o Prophase nuclear membrane disappears and framework of microtubules in formed spindle fibers also form o Prometaphase The stage of mitosis or meiosis in which the nuclear membrane disintegrates the centrioles reach the poles of the cell and the chromosomes continue to contract o Metaphase each chromosome is positioned along central axis of cell known as metaphase plate o Anaphase centromere splits into 2 causing sister chromatids to separate once separated each chromatid is considered a chromosome pulled to opposite sides of cell o Telophase daughter nuclei begin to form at each pole o Cytokinesis cytoplasm divides resulting in 2 genetically identical daughter cells 1 Replication The duplication of genetic material 2 Transcription Transcribing the genetic code of DNA into RNA molecules 3 Translation RNA following DNA s instructions for building proteins from amino acids Terminology Histone protein that DNA is wrapped around Chromatin the material of which the chromosomes of organisms are composed It consists of protein RNA and DNA Nucleosome a structural unit of a eukaryotic chromosome consisting of a length of DNA coiled around a core of histones Sister chromatid two identical copies of a single chromosome Centromere the point on a chromosome by which it is attached to a spindle fiber during cell division Genome the haploid set of chromosomes in a gamete or microorganism or in each cell of a multicellular organism Somatic cell any cell of a living organism other than the reproductive cells Gamete a mature haploid male or female germ cell that is able to unite with another of the opposite sex in sexual reproduction to form a zygote Mitosis a type of cell division that results in two daughter cells each having the same number and kind of chromosomes as the parent nucleus typical of ordinary tissue growth Meiosis a type of cell division that results in four daughter cells each with half the number of chromosomes of the parent cell as in the production of gametes and plant spores G1 phase The G1 phase or Gap 1 phase is the first of four phases of the cell cycle that takes place
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