<span>An object to be considered alive must have these characteristics.
1. Acquire and uses energy.
2. contains genetic programme.
3. composed of one more cells.
4. Respiration.
5. Must be able to grow.
6. Must be able to reproduce.
7. Must have a metabolism.
8. Must be able to respond to its environment. 9. Must be made of cells.</span>
Answer: Loess is the fine grained material that has been transported and deposited by the wind. The answer is <u>A.</u>
Explanation:
Since the wind can carry these types of material (find grained) father than sand, and also higher up, they are generally found very far from their original place of origin.
Loess is no larger than 50 micrometers in size. It is coarse in texture like clay, but finer than a grain of salt.
D. would be the answer because they are all within the eukaryote kingdom
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.
