In addition to physical traits, gene sequences can be used when comparing related species. Instead of looking for the presence or absence of a specific gene, you would look at the percent similarity between the same gene in two or more species. Therefore, it is important to select a gene that contains a similar DNA gene sequence in each of the species being compared. Certain genes are involved in processes that are required for basic cellular function. As these processes are critical to cell function, the genes that regulate them are highly conserved, meaning that they have remained essentially unchanged over time. Glycolysis is one such process that is critical for cellular metabolism. Glycolysis involves converting glucose into pyruvate in order to generate ATP, the energy currency of the cell. Because glycolysis is an essential process for all species, the genes involved are therefore highly conserved. You will be looking at similarities among different taxa of the highly conserved gene GAPDH, which codes for glyceraldehyde 3-phosphate dehydrogenase, a critical enzyme for the process of glycolysis. A mutation in GAPDH that diminishes its activity would slow down or block the 6th step in glycolysis. This would reduce the ability of the cell to make ATP from glucose and would thus put the cell at a competitive disadvantage compared to other cells with wild-type GAPDH. Therefore, mutations in GAPDH would be selected against over time, leading to this gene sequence being highly conserved among species. In order to use DNA comparison to infer the evolutionary relationship among groups, a gene that shows some variation over time must be selected but should not include so many changes that it is difficult to align the DNA sequences and compare the genes. Highly conserved genes are excellent for this purpose. Actual DNA sequences for these conserved genes are identified and then aligned to determine the amount of variation from species to species. You will learn how to do this in the next part. In order for GAPDH to be useful for inferring evolutionary relationships among lancelet, lamprey, bass, frog, turtle, and leopard, which statements must be true? Select all that apply. - The GAPDH gene must be variable enough that there are at least a few differences among the six taxa. - The GAPDH gene must be present in all taxa, except for lancelet. - The GAPDH gene must be conserved enough that the sequences from the six taxa can be aligned for comparison. - The GAPDH gene must not contain any insertions or deletions.
In addition to physical traits, gene sequences can be used when comparing related species. Instead of looking for the presence or absence of a specific gene, you would look at the percent similarity between the same gene in two or more species. Therefore, it is important to select a gene that contains a similar DNA gene sequence in each of the species being compared.
Certain genes are involved in processes that are required for basic cellular function. As these processes are critical to cell function, the genes that regulate them are highly conserved, meaning that they have remained essentially unchanged over time. Glycolysis is one such process that is critical for cellular
You will be looking at similarities among different taxa of the highly conserved gene GAPDH, which codes for glyceraldehyde 3-phosphate dehydrogenase, a critical enzyme for the process of glycolysis. A mutation in GAPDH that diminishes its activity would slow down or block the 6th step in glycolysis. This would reduce the ability of the cell to make ATP from glucose and would thus put the cell at a competitive disadvantage compared to other cells with wild-type GAPDH. Therefore, mutations in GAPDH would be selected against over time, leading to this gene sequence being highly conserved among species.
In order to use DNA comparison to infer the evolutionary relationship among groups, a gene that shows some variation over time must be selected but should not include so many changes that it is difficult to align the DNA sequences and compare the genes. Highly conserved genes are excellent for this purpose. Actual DNA sequences for these conserved genes are identified and then aligned to determine the amount of variation from species to species. You will learn how to do this in the next part.
In order for GAPDH to be useful for inferring evolutionary relationships among lancelet, lamprey, bass, frog, turtle, and leopard, which statements must be true? Select all that apply.
| - The GAPDH gene must be variable enough that there are at least a few differences among the six taxa. |
| - The GAPDH gene must be present in all taxa, except for lancelet. |
| - The GAPDH gene must be conserved enough that the sequences from the six taxa can be aligned for comparison. |
| - The GAPDH gene must not contain any insertions or deletions. |
Trending now
This is a popular solution!
Step by step
Solved in 6 steps
