In an experiment the HYPOTHESIS is tested. The hypothesis is the assumption, that you make about something. Example would be, you believe (hypothesize) that the baking soda will react faster in vinegar than in water. You then test it out (or preform and experiment) to see if your hypothesis is correct or wrong.
Answer:
D the train
Explanation:
The train is safe very fast and was the first built
The wall of the heart<span> consists of three </span>layers<span>: the epicardium (external </span>layer<span>), the myocardium (middle </span>layer<span>) and the endocardium (inner </span>layer<span>). The epicardium is the thin, transparent </span>outer layer<span> of the wall and is composed of delicate connective tissue.
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Answer:
<em>When focusing on a slide, ALWAYS start with either the 4X or 10X objective. Once you have the object in focus, then switch to the next higher power objective. Re-focus on the image and then switch to the next highest power.</em>
Answer:
a. p53 activates transcription of WAF1.
Explanation:
<u>WAF1 transcription occurs independent of p53 during oxidative stress so p53 does not play any role in cell cycle arrest in the signaling pathway which involves WAF1 . </u>
In rest of the mentioned options, p53 plays a role directly or indirectly. During double stranded lesion in DNA in G1 phase, a sensor protein known as ATM binds the DNA lesion site. ATM is a serine/threonine kinase which phosphorylates another kinase known as chk2. After phosphorylation,<u> chk2 stabilizes transcription factor p53.</u> p53 further acts as a transcription factor for the synthesis of a protein known as p21 which inhibits G1 phase specific CDK and ultimately cell is arrested in G1 phase. The cell remains in arrested state until the DNA lesion is fully repaired. <u>Hence, p53 indirectly blocks G1 to S transition with the help of p21. </u>
As such <u>WAF1 transcription factor involving pathway</u><u> </u><u>also requires p21 protein for causing cell cycle arrest but in this pathway p21 is not synthesized with the help of p53. </u>
