Answer:
Explanation:
A. Inactivation of an enzyme that degrades M-Cyclin.
M-phase cyclins form M-CDK complexes and drive the cell's entry into mitosis from G2 phase as non-degradation of M-Cyclin resulting from inactivated enzyme can only result in constitutive entry of the cell in to M phase instead cell cycle being arrested at G2 phase,
B. Inactivation of the Wee-1 kinase.
Wee1 is a nuclear kinase that plays a key role in regulating cell cycle progression. Wee1 inhibits the entry of the cell into M phase by inhibiting Cdk1. Wee1 phosphorylates Cdk1 there inhibiting the kinase activity of Cdk1 which is essential for progression from G2 to M phase. As such any mutation of wee1, and the resulting loss of activity will result in premature entry of cells into M phase instead of getting arrested at the G2 phase resulting in smaller yeast cell.
C. Inactivation of the Cdc25 phosphatase
CDC25 phosphatases removes inhibitory phosphate residues from cyclin dependent kinases resulting in the activation of CDKs which causes the cells in G2 phase to entry to M phase. Mutation in CDC25 phosphates removes the ability of CDC25 to remove phosphate residues from CDKs thus preventing the entry into M-phase.
Therefore, mutant phenotype of cell cycle arrest prior to M phase can only result form mutation in
Cdc25 phosphatase(option 3)
When wood burns the mass of the soot ashes and gases equals the original mass of the charcoal and the oxygen when it first reacted
Fog occurs in inlets and bays when the water temperature is warm enough for water vapor to evaporate off of these water bodies and the external temperature is cool enough close to the bodies of water for condensation to occur. The water vapor from the water bodies contain nuclei by which the clouds can form and if the air is cool enough this will occur over the water body relatively quickly. This may occur more in the early mornings or late afternoons.
Answer:
a. hemoglobin in red blood cells
Explanation:
Carbon dioxide is constantly produced by cells during cellular metabolism (cellular respiration), generating a concentration difference between the interior of the cell and its exterior (intercellular or interstitial space), and a consequent diffusion of this carbon dioxide into the interstitial fluid. Interstitial fluid now has a higher concentration of carbon dioxide than blood plasma, which causes a diffusion into the capillary. Carbon dioxide is carried by hemoglobin or dissolved in plasma.
