"The number of growth rings" is by far the best indicator of the age of a woody plant, although it should be noted that there are other ways of indicating age.
To reproduce (asexually). Most unicellular organisms only live for mere hours. The best bet for the species to survive and thrive as a whole is for them to reproduce, or replicate.
Answer:
ubiquitin targets CDKs
Explanation:
Cyclins are named such because they undergo a constant cycle of synthesis and degradation during cell division. When cyclins are synthesized, they act as an activating protein and bind to Cdks forming a cyclin-Cdk complex. This complex then acts as a signal to the cell to pass to the next cell cycle phase.
Cyclins drive the events of the cell cycle by partnering with a family of enzymes called the cyclin-dependent kinases (Cdks). A lone Cdk is inactive, but the binding of a cyclin activates it, making it a functional enzyme and allowing it to modify target proteins.
