More info please? Maybe a pic and the answer choices :)
Answer No 1)
<em>The correct option is D) The two species have a common ancestor</em>
Homologous structures can be described as organs or other structures which are similar in different organisms. These structures might not perform the same function, but are similar in their making. This similarity of structures between organisms of different species suggests that there might be a common ancestor for these organisms.
Answer No 2)
<em>The correct option is B) Y, Z, X</em>
The organism Y is the most similar to the worm because it has all the amino acid sequence similar to the portion shown for the worm, except for a single amino acid which is S. The sequence Z has more similarities with the amino acid sequence for the enzyme from a worm than the sequence of the organism X. Hence, the correct option is B.
Answer No 3)
<em>The correct option is A) Sequence the same gene in both species to compare their similarity.</em>
The process of DNA sequencing has now made it possible to determine the evolutionary histories among organism by comparing the DNA sequence of one organism to the DNA sequence of another organism. The organisms having similarities in the DNA sequence clearly determine the evolutionary relationship between any organisms.
Answer No 4)
<em>The correct option is C) Vestigial</em>
Vestigial structures can simple be described as structures which had some function to perform in the ancestors but are not known to perform any function in organisms known today. These structures show that evolution might have caused these structures to non- performing structures as they were of less benefit to the organisms present now on Earth.
No image is attach which means there is no model to be referenced from
Answer:
B -the absence of the inducer, but not in its presence
Explanation:
In positive repressible regulalor mechanisms transcription of the structural gene(s) occurs in the absence of the inducer because proteins are normally bound to the pertinent DNA segment. when an inhibitor is bound by the inducer, it is prevented from binding the DNA. which will the stops the activation and transcription of the structural genes.
Example of positive repressible regulator is Activator .
Regulating the rate of transcription is a mechanism of gene regulation leading to the productionn of more than one protein product from a single gene.
