Answer:
D. geographic isolation.
Explanation:
As the Grand Canyon formed, it became a physical barrier to the mixing of squirrels from its northern and southern sides. Each squirrel population was confined to a single side. This type of separation is referred to as geographic isolation.
Answer:
A. One cell took over another cell
Explanation:
Mitochondria is an organelle present in a eukaryotic cell that performs the function of producing ATP molecules from the available substrates in the cell.
The mitochondria organelle has its DNA other than the cellular DNA which shows that it was once an independent organism. This was proved by the endosymbiotic theory that during the formation of the eukaryote cell, the proto-eukaryote engulfed the chemosynthetic bacteria which later formed the symbiotic relationship with the cell and evolved into the mitochondria.
Thus, Option-A is the correct answer.
Answer:
glycine and proline
Explanation:
First, a three-dimensional stranded structure is assembled, with the amino acids glycine and proline as its principal components. This is not yet collagen but its precursor, procollagen. Procollagen is then modified by the addition of hydroxyl groups to the amino acids proline and lysine.
boom.
Animal behavior researchers often refer to an activity associated with punishment or reward as an operant. The basis for training animals is the operant conditioning. It is a learning process where the animal would learn base from its behavior as it responds to its environment. In this type of learning, the behavior is either increased or decreased by the results that follows the action. It uses rewards and punishments in order to associate with the behavior. For instance, you are trying to teach your dog to fetch an object, if he succeeds in fetching the object, then you give your dog a treat. The dog would think that what it is doing is good and that it would get a reward from it so it would start learning the behavior.
"organ, organ system, organism" is the one among the following that represents a correct sequence of levels within the hierarchy of life. The correct option among all the options that are given in the question is the last option or option "D". I hope that this answer has come to your help.