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.
Answer:
The sugar molecules in the marshmallow are being changed into carbon. Sugar can be changed into water molecules. When you toast marshmallows, the heat causes a chemical reaction producing water molecules which then evaporate, leaving the carbon behind.
Explanation:
White blood cells increase as they are the cells that destroy pathogens
a replication process carried out by a virus within a bacterial cell
It is necessary because Oxygen demands need to be reduced. This may require more aggressive support
including the use of continuous positive airway pressure (CPAP) or mechanical
ventilation. Newborns born to drug-addicted mothers exhibit hyperirritability,
exaggerated reflexes, and transient tachypnea.
