Biology Final: Module 8 (A+ Graded 100% Verified)

Biology Final: Module 8 (A+ Graded 100% Verified) True Breeding - If any organism has a certain characteristic that is always passed on to its offspring, we say that this organism bred true with respect to that characteristic. Allele - One of a pair of genes that occupies that same position on homologous chromosomes Recessive Allele - An allele that will not determine the phenotype unless the genotype is homozygous in that allele Monohybrid Cross - A cross between two individuals, concentrating on only one definable trait Dihybrid Cross - A cross between two individuals, concentrating on two definable traits Autosomal inheritance - Inheritance of a genetic trait not on a sex chromosome Phenotype - The observable expression of an organism's genes Dominant Allele - An allele that will determine phenotype if just one is present in the genotype Autosomes - Chromosomes that do not determine the sex of an individual Antigen - A protein that when introduced in the blood, triggers the production of an antibody Mutation - A radical chemical change in one or more alleles Who is the father of modern genetics? - Gregor Mendel Mendel's 4 principles of genetics - 1) The traits of an organism are determined by its genes 2) Each organism has two alleles that make up the genotype for a given unit 3) In sexual reproduction, each parent contributes only one of its alleles to the offspring. 4) In each genotype, there is a dominant allele. If it exists in an organism, the phenotype is determined by that allele In sexual reproduction, how many alleles does each parent contribute to its offspring? - One In each genotype, there is a dominant allele. If it exists in an organism, the __________ is determined by that allele. - Phenotype In humans, the ability to roll one's tongue is a dominant genetic trait. If "R" represents this allele and "r" represents the recessive allele, what are the possible genotypes for a person who can roll his tongue? - RR or Rr For a given trait, how many alleles does a normal gamete have? - One For a given trait, how many alleles does a non-gamete cell have? - Two The ability for a person to taste PTC is a dominant genetic trait "T", while the inability to taste PTC is recessive "t". If a man is heterozygous in that trait, what is his genotype? If a woman cannot taste PTC, what is her genotype? Determine what percentage chance of each genotype for the children of the man and woman above? - Tt tt 50% Tt and 50% tt Hemophilia is a sex-linked, recessive trait. Write the Punnett square for a non-hemophilic man having children with a woman who carries but does not have the disease? What percentage of girls will have the disease? Percentage of boys? - None 50% Why do recessive phenotypes in sex-linked traits show up in males significantly more often than in females? - In sex-linked traits, there is no allele on the Y chromosome. Thus, males have only one allele (X). Your chance of expressing the recessive phenotype is better if you only have one allele. Why would you not expect twins (who have identical DNA) to be identical in every way? - Genetics is only part of a person's makeup. Environmental and spiritual factors play a role as well. Name four means by which genetic disorders arise. - Any 4 of the following: autosomal inheritance, sex-linked inheritance, change in chromosome structure, allele mutation and change in chromosome number. If a trait is controlled by alleles that are non-dominant, the traits exhibited by the organism is said to have... - Incomplete dominance If a mother and father have blood types A and O, what are the types of blood possible in the children? - either A or O Change in chromosome structure is a situation in which a chromosome losses or gains genes during... - Meiosis When drawing a Punnett Square, the "male" goes on which portion of the square? - Top When using letters to fill in a Punnett Square, the dominant trait is in upper or lower case? - Upper case When a parent has one recessive allele and one dominant allele and the other parent does not have this recessive allele (has both dominant alleles), how will the recessive trait manifest? - It will remain dormant as a recessive allele If a person has a recessive trait ("t")manifest itself what does her genotype look like? - tt When an antigen is introduced into the blood, the body's response is to produce what? - Antibodies A diagram that follows a particular phenotype thru several generations is called what? - Pedigree The "+" and "-" in a person's blood type refers to what? - Rh factor (Rhesus factor) Some traits are sex linked, which means the alleles that define those traits are found on the what? - Sex chromosomes If traits are seemingly mixed and one or another trait is not "dominant" this is called what? - Incomplete dominance