Answer:
An example of a pathological condition that affects the skeleton is Osteoporosis
.
Explanation:
Osteoporosis is a disease that affects the skeleton in which the quality and density of bone are reduced. In this condition, the chances are high for easy bone fracture as they become fragile. Bone density takes place in very silently but progressively.
Osteoporosis condition leads to higher bone loss (osteoblast) than the growth of new bone (osteoclast). Bones become like a honeycomb, fragile and easy to fracture. This pathological condition generally occurs due to the imbalance of hormones that are a parathyroid hormone, estrogen, and to a lesser extent of testosterone.
This condition can be prevented by proper diet and appropriate amount of protein and vitamin D.
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)
I believe the appropriate answer is, short amino acid chains, NAG, NAM, and some lipid proteins.
Peptidoglycan is also known as Murein, it is a polymer consisting of sugars and amino acids that form a mesh-like layer outside the plasma membrane of most bacteria, forming the cell wall. The sugar component consist of alternating residues of β-(1,4) linked N-acetylglucosamine (NAG) and N-acetylmuramic acid (NAM),