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Natural Science
NATS 1675
Robert Crippen

Chapter 18 pp. 437-440 Chapter 20 pp. 475 - first 1/2 of 479 pp484-486 Chapter 6 - last 3 pages Re: blood typers and Rb factors Not required reading but it would be helpful Not proteins synthesis, genetic engineering* First Test/ Exam 13 Feb 2013 ~ CLH I - Upstairs Room 307 [ One seat between each person] 43 multiple choice - 7 True and False - Interpreting the figure into the multiple choices. Coverts chapter 18 (P. 436 and continue in the next page) and 3 , chapter 22 (Check for required reading in notes). Bring pencil and erased. Genetics / Starting with Chapter 20 Genetic is the study of the heredity. Genetics include the transmission of traits = characteristics. From generation to generation by birth, also of how study express traits. Also the study of heritage differences on how they originated and how they related to individual genetic program. Genetic is also concern in the transmission of Lineages = family tress, pedigrees, successive generations. It’s also the distribution of heritable traits within the population that make up a given species. (Population is certain specie within an area). The blueprint or plant was in charge of the transmission of traits where carry on the molecules of DNA which make up genes and chromosomes. DNA = deoxyribo nucleic acid. DNA chemical molecules. Genes are the basic units of inheritance. More specifically, the genes are the smaller segment of the chromosomes that code for 1 whole protein or a polypeptide chain. Polypeptide chain = Part of a protein It’s from this blueprint or the genes that the information comes to build and operate the cells. Cells --> Tissues --> Organ --> Organ System--> Organism The majority of the proteins are synthesized by genes function as enzymes. Enzymes regulate the vast majority of chemical processes of our bodies. Chromosomes are treating like structure formed or founded in the nucleus. Chromosomes contain the genes, determine the sex of the individual and are normally constant with the number among the species. These chromosomes are made of two chromatids sister. Variations in chromosomes numbers can and do occurs, this are call chromosomal abnormalities (mean abnormal number of chromosomes). Genes are copy in the reproduction in the cell of an organism; errors sometimes made are call mutation. Mutation is the process of change in the genetic material DNA, which determines the traits of specie. Cause includes: 1. Accidents of nature: it just happen 2. Certain chemical compounds 3. Viruses 4. Radiation ~ will include natural, ultraviolet, medical, industrial & including weapons. Mutations are heritable errors; mutations result in diverse species but not all organisms a species are equally suited for survival. Mutation that provides 1% of advantage among the other species, this one survives. (Have more offspring) Mutation that does not provide any particular advantage, frequent result in the elimination of the organism. Genetic diseases are the oldest, most wide spread and probably the most burdensome of all human affection. It is estimated about 8% of all North America are affected by some disease involving disorder in material. 80% of birth defects contain genetic components, the other 20% result to environmental factors such as infections, particular diseases, drugs, radiation, physical injuries, etc. Other diseases have been showing to have a genetic component to develop a particular disease. I.e. heart disease, familia hypertension (family related high blood pressure), certain forms of arthritis, diabetes, certain cancers, certain mental illnesses (i.e. schizophrenia & manic depressive disorder = bipolar) Genetics Overheads Species is defined as populations of organisms that retain their individuality in nature because they are reproductively isolated from other species around them. Reproductive isolation includes both behavior and genetics. / Check the handout/ Genotype ~ can be talking about particular genes. Double RR is a dominant, rr recessive & the Rr is the hybrids. Phenotype ~ how it looks? What it look like? You will not be able to see it. If both genes are the same it’s when they show up. Alleles ~ A B O blood types/ nobody can have an A B O blood type together. Dominant ~ it’s when the dominant show up. For example RR both of them are dominant & in Rr, the R is the dominant and show up. Homozygous ~ i.e RR and rr Heterozygous ~ i.e Rr Hybrids ~ organisms produce from two different species or genotypes. Common example will be: Female horse + male donkey --> muel Female donkey + male horse --> hinny / basically are useless. The “Father of Genetics" is Gregor Mendel, an Austrian monk, who presented his research in 1865. Mendel's paper contained 3 major generalizations: 1) The Principle of Dominance, 2) The Principle of Segregation, and 3) The Principle of Independent Assortment of Recombination. 1) Dominance -- When parents differ in one characteristic, their offspring (which are hybrids) resemble one or the other parent, not a blend. RR (round) x rr (wrinkled) = Rr (Round) 2) Segregation -- When a hybrid (e.g., offspring from the above parents) reproduces, its reproductive cells are of 2 kinds -- half transmitting the dominant character of 1 of its parents, and the other half transmitting the recessive character of its second parent. [Alleles for any given trait in homologous chromosomes separate (segregate) into separate gametes.] 3) Independent Assortment or Recombination ~ when parents differ in 2 or more pair of characters, each pair shows dominance and segregation independently of the other pairs. * Applies to the inheritance of 2 or more traits * Genetic information for each trait is distributed to gametes independently of the distribution of the other traits. [Refers to the random separation or segregation of 2 or more pair of alleles as long as they are on different chromosomes.] Mendel worked with the common garden pea using 7 distinct alternate pairs of characteristics including seed shape (round vs. wrinkled ripe seeds), seed color (yellow vs. green seed interiors), and pod shape (inflated vs. pinched pods), stem height (tall vs. dwarf), etc. [Fig B, page 4] The pea plant was a good experimental plant because it is self-fertilizing, and self-fertilizing plants tend to bread 'true', i.e. the offspring usually exactly resemble their parents. Also, each trait studied was on a separate chromosome which was fortuitous because Mendel would have had no knowledge of this fact. Punnett Squares: P1 = Parental Generation - The parents - the starting point. F1 = First filial generation = offspring of the P1 F2 = Second filial generation = offspring of F1 Round x wrinkled --> only round seeds (F1) Cross plants from the F1 --> 3/4 Round, 1/4 wrinkled = F2 5474 Round: 1850 wrinkled 2.96:1 = 3:1 A Punnett square is a way of diagramming the assortment of alleles in the gametes of the parents. It is also as way to determine the probability that a particular genotype or phenotype will be produced [or to determine the probability of the various possible offspring]. By convention female gametes (eggs/ova) are placed on the top of a Punnett Square; male gametes (pollen/sperm) are placed on the left side of a Punnett Square. * Outside the square it’s the gametes; inside the square is the offspring. 1 pair of genes = monohybrid cross. R = Round ~ Dominant r = wrinkled ~ Recessive All female gametes are grouped together on the top. All male gametes are grouped on the side. P1 = RR [male] x (cross or mating) rr [Female] [Use a slash between the letters to separated] So it’s going to be a square with RR in the vertical line and rr in the horizontal line on top. On in every square that are located inside there would be an Rr. F1 all = Rr heterozygous Round F1 = Rr x Rr So in the Pennett Square, the Rr is going to be located in the vertical and horizontal line. Which make the little square inside have RR, Rr, Rr and rr. Genotype 1 RR; 2 Rr; 1 rr / Phenotypes for RR: 1 Round; for @ Rr its 2 Rounds (since the R is dominant); for rr 1 Wrinkled. Genotypic Ratio 1:2:1 and 1:1:2 F2 = Rr x rr In the Pennett Square, the Rr it’s going to be place in the vertical line and the rr in the horizontal top line. Making it Rr, Rr, rr and rr. Genotype: 2 Rr and 2 rr. Phenotype of 2 Rr is going to be 2 Round and for 2 rr; it’s going to be wrinkled. Genotypic ratio will be 2: 2 = 1:1/ 2:2 = 1:1 Phenotypic radio A dihybrid cross considers 2 pairs of alternate characteristics at the same time, e.g. see shape (round or wrinkled) and seed color (yellow or green). Dihybrid crosses exemplify Mendel's third principle - the Principle of Independent Assortment or Recombination - the random segregation or separation of 2 or more pairs of alleles as long as they are on different homologous chromosomes. Dihybrid Crosses: considers 2 pairs of alternate characteristics R = Round seeds, r = Wrinkled seeds, Y = Yellow seed color, and y = Green see colour P1 = RRYY X rryy F1 = RrYy R [Y (RY) and y(Ry)] r [ Y (rY) and y (ry)] 2n 2 exponents 2 = 4 2 exponents 3 = 8 P1 AABBCC x aabbcc ; we use a slash to separate the A with A and a with a. F1 AaBbCc ; the A separated independetly and then its check below... F1 RrYy x RrYy Gametes RY Ry rY ry / The CAPITAL LETTER ALWAYS GO FIRST 1 RRYY = 1 ROUND YELLOW 2 RRYy = 2 ROUND YELLOW 2 RrYY = 2 Round Yellow 4 RrYy = 4 Round Yellow 1 RRyy = 1 Round Green 2 Rryy = 2 Round Green 1 rrYY = 1 Wrinkled Yellow 2 rrYy = 2 Wrinkled Yellow 1 rryy = 1 Wrinkled Green 9 Round Yellow: 3 Round Green: 3 Wrinkled Yellow:1 Wrinkled Green HOMEWORK RrYy x Rryy The early studies come from study disorders and abnormities that ran in families. The human genome contains about 3 billion bases. The average functional gene contains about 3000 bases. Nucleic acids - DNA and RNA ~ only 5 bases Each has 4 bases, 3 bases are common to each. RNA gets the message from DNA to produce proteins and it is the RNA which is involved in creating and producing proteins. Most relationships that we have discussed are monogenic. Monogenic: simple Mendelian patterns if inheritance; control by a single type of genes or alleles. Example: 1. Albinism 2. Attached/ unattached earlobes 3. Tongue rolling 4. Bent little finger Some traits controlled by several genes - sometimes located at different locations. Polygenic or multiple allele. Polygenic inheritance - 2 or more pairs of alleles are necessay for a given phenotypic expression. Colour of skin, hair and eyes are examples of polygenic inheritance. Monogenic - different phenotypes are controlled by a single pair of genes. They are also referred to as simple Mendelian patterns of inheritance. Multiple allele - More than the normal 2 alleles are present at a locus in a chromosome within the population. ABO blood groups are examples of multiple alleles. Other phenotypic expressions are genetic an nongenetic factor. Example: height, intelligence and baldness. Cumulative effect: (erroneously referred to as incomplete dominance) refers to the condition that hybrids are distinguishable from their parents, i.e. red flowers (RR) x white flower (rr) --> pink flower (Rr). In other words, the alternate forms of the alleles are neither dominant nor recessive; the phenotypic expression within a heterozygous offspring is a blend. Melanocytes ~ specialized cells scattered among the cells of the epidermis that produce the main pigment (melanin) in human skin. Birth marks are areas of the skin that are lighter or darker than normal. The number of melanocytes in these areas are usually normal but they produce more ... Pigmented moles have more than the usual number of melanocytes in that particular area. The differences in the amount of segmentation exhibited in the ratio group are due of the differences of synthesized melanocytes been produce and not differences in melanocytes in numbers. Normal skin has the same number of melanocytes. There are also other molecules that influence in the colour of the skin, one of them are carotenes (You can find it in the orange and produce a yellow colour) , Hemoglobin (this produces a reddish colour). Genotypes & Phenotypes for Skin Colour AABB } Black; ~ The A gene travel in different chromosome than the B gene. AaBB & AABb } Dark; AAbb & aaBB & AaBb } Medium; Aabb & aaBb } Light aabb } White P1 = AABB (female) x aabb (male) F1 = AaBb medium AaBb x AaBb --- Check notebook Blood Types A B + O ~ th
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