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)
<span>Genotype is genetic and phenotype is environmental. An organisms genotype is total genome determines its characters. Genome is the total genes for all the characters. Its outcome is called phenotype. It is greatly influenced by the environemental factors. Same genotype may produce different phenotypes in different environments.</span>
Can you please attach the diagram for reference to assist in answering your questions
Answer: Eukaryotic cells — those that make up cattails and apple trees, mushrooms and dust mites, halibut and readers of Scitable — have evolved ways to partition off different functions to various locations in the cell. In fact, specialized compartments called organelles exist within eukaryotic cells for this purpose. Different organelles play different roles in the cell — for instance, mitochondria generate energy from food molecules; lysosomes break down and recycle organelles and macromolecules; and the endoplasmic reticulum helps build membranes and transport proteins throughout the cell. But what characteristics do all organelles have in common? And why was the development of three particular organelles — the nucleus, the mitochondrion, and the chloroplast — so essential to the evolution of present-day eukaryotes.
Explanation:
