The correct sequence of levels is shown by choice A.
Answer:
Due to absorption of more water.
Explanation:
A Cotton shirt takes more time to dry as compared to a synthetic shirt due to absorption of more water by the cotton fiber as compare to other fiber. Cotton absorbs much more water than other synthetic fibers, and attached to the molecules of cotton for longer period of time which means cotton fibers take more time to dry as compared to synthetic fiber which absorb little amount of water and loosely attached to the molecules of fiber.
Yes Darwin’s theory of natural selection
Follicle cells in your scalp assemble proteins to build new hair. This most likely involves dehydration synthesis reactions.
Dehydration synthesis forms a peptide bond between amino acids and releases a water molecule. Amino acids connected via peptide bonds form a polypeptide chain, which then chemically interact with other polypeptides in order to create a complex three-dimensional structure of the protein.
Answer:
All of these choices are correct.
Explanation:
Cell cycle is the process of growth and division of cell. It comprises of interphase and mitosis. In interphase the cell grows, replicates its genomic content and prepares itself for division. In mitosis the division occurs.
Cell cycle is controlled by a group of kinases called as Cyclin dependent Kinases (CDKs). They act by phosphorylating their substrates. They are of various types like Cdk1, Cdk2, Cdk4 etc. They become active when they bind to a regulatory protein called cyclin. They are also of various types like Cyclin A, Cyclin B, Cyclin C etc. Level of cyclin and corresponding CDK increases and decreases according to the stage of cell cycle. For example in S phase of cell cycle concentration of cyclin A and E shoots up. CDK2 is able to bind to these cyclin molecules and hence it becomes active.
Cell cycle has major checkpoints where the condition of cell is analysed before it proceeds to the next stage of cycle. If any abnormality is detected, repair mechanism is activated or the cell is killed. Checkpoints do not allow cell cycle to proceed in damaged cells.
p53 is a tumor suppressor protein which can halt cell cycle when it detects some abnormality in cell. It usually acts in G1/S checkpoint (before the DNA replication starts in cell) and G2/M checkpoint (before the cell division begins). Hence, all of the above statements are true.
