Cell division is preceded by two growth phases. Besides growth, both G1 and G2

A

Explanation:

a. contain checkpoints that determine if the cycle will continue.

b. help move chromosomes to the new daughter cells.

c. produce more chromosomes before the cell divides.

d. grow and produce enough cytoplasm to fill two cells.

The correct answer would be that G1 and G2 contain checkpoints that determine if the cycle will continue or otherwise.

The cell cycle generally has three checkpoints that happen at G1, G2, and M phase of the cycle.

At G1 checkpoint, the integrity of the DNA of the cell is assessed to ensure that there are no damages and other conditions such as size and energy reserve are checked.

At G2 checkpoint, the cell is assessed for proper chromosome duplication to ensure that there are no mistakes or damages. The size of the cell and the amount of protein are also checked to ensure that the cell is ready for the active division phase.

At M checkpoint, correct attachment of the spindle fiber to the kinetochore of the chromosomes is checked. This checkpoint is also known as the spindle checkpoint and it happens towards the concluding phase of the metaphase stage.

The correct option is therefore, A.

meteorologists would compare a new weather map with one 24 h old to see how fast a front is moving.

sheep is a herbivore animal whereas grasshopper belongs to the class chordates but both of them feed on greens.  

if grasshopper and sheep feeding on a pasture land, i do not think both of them will have any impact on each other. however, the number of the species can make difference. since sheep feed on greens, there is a possibility there left no pasture land for the grasshoppers or they may get extinct.