What+is+HEREDITY?

Q. 23 __Polyploidy__ is a genomic mutation that makes an individual have more than two sets of chromosomes. __Monosomy__ is the genomic mutation that makes an individual lose a chromosome (2n-1) __Trisomy__ is a genomic mutation that makes and individual have an extra chromosome (2n+1) __Q. 24 Nicotine__ is an organic compound (alkaloid) that is extracted from tobacco leaves, although it can also be produced in a laboratory. Its effects on the organism are varied. It is psychoactive drug and can generate a very strong addiction to whoever uses it. In high doses it has a sedative effect given that it acts as a depressant. Q. 25 Mutation that occurs in somatic cells appear in the individual that possesses the mutation, but __will not be transmited to offspring__. Mutations that occur in __sexual cells can actually be transmited to offspring__. Q. 26 An organism affected by __monoploidy__ presents __one set of chromosomes only (n)__ In a monosomy there is one chromosome less ( 2n-1). Obviously, the genetic alteration would be bigger in the monoploidy. ** Q. 27 If the mutation occurs in one nitrogenous base only, would it have important consequences for the organism? **  yes, because the change in one nitrogenous base can change an amino acid and then have an effect on the structure of a protein. **Q. 29** Somatic mutations are those that occur in somatic cells. Germinal mutations take place in sex cells (gametes). Germinal mutations can be transmitted to offspring, on the other hand somatic mutations cannot be transmitted to offspring. **Q. 30** When we observe the sequence we can see that there is a beneficial mutation and a very beneficial mutation. As a result, due to the process of natural selection, the very beneficial mutation increases within the population until the entire population has it. **Q. 31** This sequence shows that a catastrophic event has occurred causing an environmental change. The __environmental change has turned the least beneficial mutation into the most beneficial mutation,__ which __has progressively been passed on to the new offspring until the entire population has it.__ _ =__Unit 3 Mendelian Genetics:__= =__Page 61 lethal genes. Q 14__= =Absence of legs in bulls and cows is caused by a recessive lethal gene.= =P: Pp X Pp= =F1__=
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= = || =p= || Genotypes 1/3 PP 2/3 Pp   Phenotypes 100% with legs   _._._._._._:-   Q.16 Results of quantitative inheritance: reptile´s leg length mammal´s height Page 63 Q. 18 Two linked genes that are in the same pair of chromosomes tend to be transmitted together, but can be  separately if genetic recombination takes place during prohase I of Meiosis. Q 19. The chromosome theory of inheritance is able to explain the cases that did not follow Mendel´s third law because the genes can be independent ( in which case they follow Mendel´s third law ) or  linked (they do not follow the law if recombination does not take place). Page 69 Q.31 A woman carries in one of her X chromosome a lethal recessive gene(l), the other X chromosome has a normal dominant one(L). If this woman has offspring with a normal man, What will the ratio of their sex be? P XX X XY  2/3 WOMEN 1/3 MEN Q. 32 Alopecia is determined by gender and is dominant in males and recessive in females  A alopecia N no alopecia Identify the genotype of a man with alopecia whose father was not bald his wife who is not bald but her mother was their future children? Not bald NN  Bald NA X NA Woman not bald, but her mother was bald(AA) Males that have AA and AN genotypes will be bald, but only the females with the genotypes AA will be bald. As a result, 3/4 of male offspring will be bald and just 1/4 of female offspring will be bald. Page 72 Q. 35 Cells involved in the transmission of characteristics from parents to offspring? Gametes  Q.36.Pure-bred individuals for a particular characteristic are those that have the same alleles in their homologous chromosomes. They are also known as homozygotes. Hybrid individuals for a particular characteristic are those that have different alleles in ther homologous chromosomes. They are also known as heterozygotes.. Q. 37 Genotype of the guinea pig shown in the image: nn. The genotypes of both parents could have been black ( Nn). Q38 In pea plants, purple flowers are dominant over white and tall stems are dominant over short stems. We can deduce the genotype of a tall pea plant with purple flowers carrying out a backcrossing (cruzamiento prueba) with a recessive homozygote for both characteristics. If the offspring have a recessive phenotype for any of the characteristics, this means that the plant was heterozygous for that characteristic. Q. 39 Correct answer: All yellow  Q. 41.Curly hair is dominant and smooth hair is recessive. Black fur is dominant over white. a) RRNN X rrnn  F1 will be RrNn   b)Final result of the Punnet Square:   9/16 curly, black hair   3/16 curly, white hair   3/16 smooth, black hair   1/16 smooth, white hair   Q. 47   An animal that has sex determination through the system XX/XY has 25 chromosomes in one cell. Is it a somatic cell or a gamete? It is a gamete ( a sex cell) because 25 is an odd number and the diploid number is always even. Q. 49  In your notebook, draw a range of possibles gametes in an individual that has the following chromosomes: If genetic recombination does not occur, the gametes will be:  AbD, Abd, aBD, aBd   If recombination occurs, there will be more possible combinations:   AbD, Abd, aBD, aBd, ABD, abD, ABd y abd   Q. 50   Correct answer: c. 50%   Q. 55. Correct answer: b. recessive
 * =P= || =PP= || =Pp= ||
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 * =X= || =XX= || =XY= ||
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 * =N= || =NN= || =NA= ||
 * =A= || =NA= || =AA= ||