You need to test the hypothesis several times and record all results. Once you obtain the same results several times, I think that means its a theory
Cytotoxic T cells are rapid killers of infected target cells. Within minutes of the interaction of a cytotoxic T cell with a target cell, the program of apoptosis in the target cell is initiated. This rapid activity is a consequence of The extremely rapid production of granzymes and perforin by cytotoxic effector cells upon encountering a target cell.
- A type of T cell known as a cytotoxic T cell (CD8+ T cell) is in charge of removing things that the immune system recognizes as dangerous.
- Cytotoxic T cells are essential for controlling bacterial growth and illnesses in the body.
- By instructing their targets to undergo apoptosis, cytotoxic T lymphocytes kill their prey.
- Cytotoxic T cells can instruct antigen-specific target cells to die within 5 minutes of coming into contact with them when they are mixed with target cells and quickly brought into contact by centrifugation.
- The speed with which cytotoxic T cells can induce apoptosis in their targets is due to the release of prepared effector molecules that trigger the target cell's own endogenous apoptotic pathway.
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Physical exercise preserves bone mass. Measurements of bone biomarkers may reflect the events in bone during exercise. Fifteen healthy, well-trained individuals (7 men and 8 women) performed a running test for 21 min until exhaustion. Venous blood samples were drawn before and 30 min after the exercise to measure the levels of osteocalcin, the carboxyterminal propeptide of type I procollagen (PICP) and the carboxyterminal cross-linked telopeptide of type I collagen (ICTP). After exercise, the women had a marked increase in serum osteocalcin concentrations (from 7.5±5.0 μg/1 to 11.5±3.0 μg/1), whereas the level was unaffected in the men (from 14.5±3.0 μg/1 to 13.5±4.6 μg/l). In the men there was a marked increase in PICP (from 240±47 μg/1 to 268±56 μg/1) that was not seen in the women (from 244±70 μg/1 to 253±60 μg/1). In neither group did ICTP levels change. In conclusion, significant responses were seen in PICP and osteocalcin during exercise, indicating that such measurements may be valuable for the further delineation of the effects of physical activity on bone. Furthermore, the different responses in men and women point to interesting areas for future studies.
A controlled experiment is when the experimenter can change one variable in the experiment and completely change the results.
Redi experiment involved a closed jar with rotting meat on the inside. He waited for a few days and found no new forms of life in the jar.
He then did the same experiment, but this time he took the lid off the jar. After those few days he found there were maggots in the rotting meat from flies.
This is a great example of a controlled experiment, because he only had to change one variable to completely change the results. In this case that variable was just removing the lid from the jar.
Redi was trying to prove spontaneous generation with his experiment. Although, it failed.
Spontaneous generation: When life forms from non-livings.
Redi disproved spontaneous generation, but proved biogenesis.
Biogenesis: When life comes from other living beings.
He proved biogenesis because the flies had reproduced when the jar was opened.
