Answer:
The earliest known life-forms are putative fossilized microorganisms, found in hydrothermal vent precipitates, that may have lived as early as 4.28 Gya (billion years ago), relatively soon after the oceans formed 4.41 Gya, and not long after the formation of the Earth 4.54 Gya.
Explanation:
Answer:
what in the world are you learning
Explanation:
Explanation:
(1) Is referring to Newton's first law, an external force (gravitational force) is applied to frogs motion, thus causing it to deviate from a straight line
(2) is referring to Newton's third law of motion, the action force is done by the ball hitting the ground and the direction is downwards, the reaction force is done by the ground transferring that same force to the ball, acting upwards
(3) I think it's also the first law, the person on a train is showing, the force to keep it at rest, the sudden halt of the train causes a reaction force to act on the person, does making the person move
(4) I think it's both Newton's second law and third law motion.
I hope these helps
Answer and Explanation:
Cyclins and cyclin-dependent protein kinases (CDPKs, cell proteins) also function to control the cell cycle. A group of cyclins: the G1 cyclins, are synthesized during G1 phase and function to activate CDPKs which initiate DNA synthesis at the G1/S checkpoint. The cell fails to progress to S phase if there is no sufficient synthesis of G1 cyclins. After a cell passes through this point, the G1 cyclins are degraded, allowing for another group of cyclins: the M cyclins (mitotic cyclins) to be synthesized. M cyclins activate a second group of CDPKs which allow the cell to pass the G2/M control point and into mitosis.
In the G1/s check point, entrance into the S phase is blocked if the genome is damaged. In the G2/M check point, entrance into the M phase is halted if the DNA replication is incomplete. In the M phase, anaphase blocked if chromatids are not properly assembled.