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Department
Biology
Course
BIOL 303
Professor
Dragana Miskovic
Semester
Fall

Description
1. Define the following terms (use your own words): development, growth, differentiation, histogenesis, organogenesis, morphogenesis, reproduction, tissue, organ, organ system, and organism. Growth : increase in size and mass (e.g. growth of organism = increase in cell numbers, or cell growth = increase in cell volume) Development : process of growth, differentiation and reproduction of an organism (includes embryogenesis, postembryonic development and adulthood) Differentiation : the structural adaptation (change) of an individual cell (or other parts of organism) which enables it to perform a particular function Histogenesis : process by which different tissue types form during development Organogenesis : process by which different organs form during development Morphogenesis : is ‘the shaping of an organism by embryological processes of differentiation of cells, tissues, and organs and the development of organ systems according to the genetic “blueprint” of the potential organism and environmental conditions. Reproduction : The sexual or asexual process by which organisms generate new individuals of the same kind Tissue : Part of an organism consisting of an aggregate of cells having a similar structure and function. (cartilage, epithelium…..) Organ : A fully differentiated structural and functional unit in an animal (organism) that is specialized for some particular function. (liver, heart, brain….) Organ system : Individual organs having specialized function(s) group into organ system (nervous system, respiratory system…) Organism : A living thing that has (or can develop) the ability to act or function independently.(= prokaryotes, protists, plants and animals) 2. Distinguish between growth and differentiation. Give an example where each occurs independently of the other. -example is growth is cleavage -cleavage and blastulation -example of differentiation is irreversible cell fate, cells aggregating into tissues and perform a certain function -stem cell turning into a red blood cell of each otherh between growth and differentiation with an example were each occurs independently a. Growth if the process of an entity increasing its size, mass, number of cells and volume whereas differentiation is when structural adaptation of a cell or a part of an organism occurs so that it can perform a function. b. During embryogenesis, growth occurs near the beginning where the zygote divides to increase its number of cells and size whereas differentiation occurs much later on when the cells become specific tissues and have specific function. ii. Differentiation = hematopoietic stem cell becoming red blood cell 3. Explain the following statement: "The entire life history of animals is cyclical." -in summary: birth, reproduction, and death 4. What are the (two) major questions that are addressed by the discipline of developmental biology? 5. Define (explain what it is) the following terms: chemotaxis, resact, agglutination (of sperm to jelly coat), capacitation, acrosome, bindin, acrosomal filament (process), activation (of the egg), cortex (of an egg), cortical granules, vitelline envelope or membrane, fertilization envelope or membrane, zona pellucida Chemotaxis: The characteristic movement of an organism or cell along a chemical concentration gradient either toward or away from the chemical stimulus Resact: A small 14 AA peptide released by the egg jelly (in sea urchins) that reacts with sperm as a chemoattractant, leading to the sperm moving towards the egg Agglutination: The process of binding the sperm and the egg by species- specific proteins (bindin on sperm) (species-specific event #2) -is the process when the bindin on the acrosomal process binds to the bindin receptor (ERB1) on the egg cell membrane Capacitation: The activation/maturation of sperm cells (esp. membrane) within the female reproductive system. Acrosome: Is a vacuole formed as a germ cell differentiates into a sperm. It is filled with lytic enzymes by the golgi apparatus and it migrates to the tip of the sperm ‘head’. When the sperm binds with specific proteins on the egg the vacuole is ruptured towards the external environment, disintegrating the egg’s protective layers. Bindin: Is a protein represented on the external membrane of the sperm after the acrosomal reaction takes place; it lines the acrosomal filament and binds to the egg membrane. -bindin is found on the acrosomal process (acrosomal process only found in sea urchins) Acrosomal Filament:an actin microfilament extension from the head of the sperm that grows where the acrosomal vesicle had previously erupted. Activation (of the egg): Begins by fusion of the sperm and egg membrane. Early phase, dependent on transient increase of intracellular calcium, leads to positively charged cell (excess sperm cannot bind), crosslinkage leads to stiffer fertilization envelope. Late stage, calcium increase inhibits MAP kinase, leads to DNA and protein synthesis, including cyclin B and cdk1 initiates cell division. Cortex: a gel like shell just under the egg cell membrane, high in globular actin (which polymerizes into microfilaments following fertilization) and contain cortical granules. Cortical Granules: structures homologous to the sperm’s acrosome. They are formed by the Golgi and contain enzymes which prevent sperm entry after fertilization (slow block). Vitelline Envelope/Membrane: an extracellular matrix (in invertebrates) which is responsible for sperm-egg recognition, analogous to the zona pellucida Fertilization Envelope/Membrane: The cavity formed, filled and fused between the vitelline envelope and the egg\ membrane. It is filled with enzymes of the cortical granules, and begins to grow from the point of cell entry. Not seen in mammals. it is a modified vitelline envelope Answer: Chemotaxis: movement toward or away from a chemical Acrosome (acrosomal vesicle): 6. List and briefly describe adaptations which increase the probability that a sperm and egg will find one another and that successful fertilization will follow. Over-production of gametes: huge numbers of sperm produced and released by the males as to increase the chance of contact between sperm and egg. Behavioral modifications in the organism: mating calls and behaviours External vs. interna
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