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

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.

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).

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.

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.

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.

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.

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.

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.

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.