New York State Chemistry RegentsNew York State Earth Science Regents

Heredity and Genetics
Living Environment Regents June 2006 Question 65 PDF Print E-mail


Species C and D. They have the same amino acids produced after protein synthesis.

Living Environment Regents June 2006 Question 64 PDF Print E-mail


Species C

DNA base sequence        CCG  TGC    ATA    CAG  GTT

mRNA base sequence     GGC  ACG  UAU    GUC   CAA

Amino acid sequence    GLY     THR     TYR      VAL     GLN

The DNA is forms mRNA complementary sequence through transcription. The nitrogenous base cytosine (C) is changed to guanine (G), or vice-versa. Adenine (A) becomes Uracil (U), and Thymine (T) is transcribed as Adenine (A). The triplet code of the mRNA base codes for the amino acids which can be seen in the universal genetic code.

Living Environment Regents June 2006 Question 63 PDF Print E-mail


Species B

DNA base sequence        TGC    TGC    ATA    CAG  GTA

mRNA base sequence    ACG   ACG   UAU    GUC   CAU

Amino acid sequence     THR     THR     TYR     VAL    HIS

The nitrogenous base cytosine (C) is changed to guanine (G), or vice-versa. Adenine (A) becomes Uracil (U), and Thymine (T) is transcribed as Adenine (A).

Living Environment Regents June 2006 Question 51 PDF Print E-mail


Specific genes code for the production for the proteins that can cause allergic reactions to the consumers. These genes will be selected and altered so that the proteins produces would not be recognized by thee body as allergens.

Living Environment Regents June 2006 Question 50 PDF Print E-mail


Correct Answer: Option 1 The altered DNA is used to synthesize changed forms of these proteins.

The proteins should be changed into another kind that is not allergy-producing. Therefore, the DNA is changed so that the genes will express the specific kind of protein that will not cause allergic reactions.

Living Environment Regents June 2006 Question 16 PDF Print E-mail


Correct Answer: Option 3 gene combinations different from those of either parent.

Option 1 is incorrect because before fertilization, the egg cell and sperm cell both underwent cell division making them haploid containing only half of the original chromosome content. Hence, the number of chromosomes of the offspring is just the same as either parent. For the same reason, option 2 is also incorrect.

Since the half each parents' genetic material has been joined together, there is variation from the offspring and the parent. Therefore, option 4 is incorrect and option 3 is the correct statement.

Living Environment Regents June 2006 Question 14 PDF Print E-mail


Correct Answer: Option 1 sheep A only

The nucleus from the egg of sheep A cannot be fertilized by the body cell (not a sperm cell) of sheep B. Therefore, the resulting cell is just the same as the genetic composition of sheep A. Sheep C cannot contribute because it is also female the egg cell was already placed on its uterus.


Living Environment Regents June 2006 Question 09 PDF Print E-mail


Correct Answer: Option 1 mutation and gene recombination.

Mutation refers to the changes to the nucleotide sequence of the genetic material of an organism. Since there is a change in the genetic information of the species, this can further cause evolution of the species. On the other hand, genetic recombination is the process wherein a strand of DNA is broken and joined to a different DNA molecule. This usually occurs during meiosis as chromosomal crossover between paired chromosomes. This leads to offspring with different combination of genes from their parents.

Mitosis involves the distribution of identical DNA to two daughter cells. Its function is primarily for growth and development, not for variations in the succeeding generations of species. Natural selection is the differential success in reproduction caused by the adaptation of organisms to their environment. Option 2 is incorrect because not both mitosis and natural selection results to variation (only natural selection causes variation).

Extinction cannot cause variation because the genetic information of an extinct species also disappears with it. Gene replacement can cause a change in the characteristics of a species. Therefore, only gene replacement is correct, making option 3 invalid.

Selection would limit the variations that could influence the evolution of species.  Selective breeding is in contrast with natural selection, according to Charles Darwin. Thus, option 4 is incorrect.

Living Environment Regents June 2006 Question 08 PDF Print E-mail


Correct Answer: Option 3 gene alteration in gametes.

Option 1 is incorrect because in cloning, the genetic information of the parent is just the same with the offspring.

Options 2 and 4 are incorrect. Mitosis in the muscle cells and differentiation in nerve cells only happens from further growth and development of the body. These cannot be inherited by the following generation.

Gene alterations in the gametes will form new inheritable characteristics. Since the gamete of the parents unite during sexual reproduction, if ever there would be alterations, the resulting diploid zygote would have a different gene expression that can be carried out to the next generations.

Living Environment Regents June 2006 Question 07 PDF Print E-mail


Correct Answer: Option 1 specific sequences of bases in DNA in reproductive cells.

Before cell division occurs, the cell first has to replicate the chromosomes so each daughter cell can have a set. Each chromosome is one long molecule of DNA with specific sequences of nitrogenous bases and special proteins. The DNA of the parent molecule is replicated to form the DNA of the offspring.

Option 2 is incorrect.  The function of proteins during reproduction is to "turn off" the genes that are not needed in that cell. For example, while every cell in your body contains exactly the same genes, you don't need your eye-color gene operational in cells in your big toe, nor toenail-shape genes active in cells in your stomach.

Option 3 is incorrect. The role of carbohydrates in reproduction is still under speculation. There are studies that have shown that glycosylation (the systematic addition of carbohydrates to proteins or lipids) contributes to the reproduction process (e.g. interaction between the spermatozoa and the zona pellucida of oocyte); however, not directly in the transmission of hereditary traits.

Option 4 is incorrect. DNA is a polymer of monomers called nucleotides, each consisting of a pentose sugar (deoxyribose) and a phosphate group. Pentose is also a kind of sugar but it is not considered as starch.

<< Start < Prev 1 2 Next > End >>

Page 1 of 2

Copyright Information

All works and materials contained within this site Copyright © 2009 Technology Strategies For Success inc.


We are not affiliated with, nor endorsed by, the New York State Education Department.

The information contained in this website is for general information purposes only. The information is provided by "Technology Strategies for Success" and while we strive to keep the information up-to-date and correct, we make no representations or warranties of any kind, express or implied, about the completeness, accuracy, reliability, suitability or availability with respect to the website or the information, products, services, or related graphics contained on the website for any purpose. Any reliance you place on such information is therefore strictly at your own risk.