Answer;
Arrangement of events in stellar formation;
C) The Big Bang occurs.
B) Pockets of elements in higher concentrations begin experiencing greater gravitational force.
A) Hydrogen atoms shed their electrons and fuse together to form larger helium atoms.
D) the glass clouds begin reducing in volume, which leads to increase in density, pressure, and temperature.
Explanation;
-Stellar evolution is the process by which a star changes over the course of time. All stars are born from collapsing clouds of gas and dust, often called nebulae or molecular clouds.
-Stars are born out of the gravitational collapse of cool, dense molecular clouds. As the cloud collapses, it fragments into smaller regions, which themselves contract to form stellar cores.
Answer:
Sperm-egg interaction
Explanation:
The formation of fertilization envelope is well-studied on the model system- sea urchin. It has been shown that, the fertilization envelope is formed after the initial sperm-egg interaction from the egg surface vitelline envelope and the paracrystalline protein fraction which is derived from cortical granules. Secretion from cortical granules, prevents polyspermy.
The four limitations are
1.It's often impossible to repeat trials on the same subjects.
2-Subjects may report an inaccurate medical history.
3-It can be difficult to control all possible variables.
4-It's impossible to come up with testable scientific questions for human subjects.
Research involving human beings is ultimately necessary for improvements in human health and welfare. Any results about healthy physiology, illness causes, treatment effectiveness, learning, or behavior must be verified by carefully controlled investigations involving human participants. Sadly, not all human research have been valid and beneficial. It is possible to harm people in the name of research. The most well-known instances happened in Nazi Germany. Investigations conducted after the war found several crimes, including experiments in which participants were submerged in extremely cold water to determine how long it would take them to pass away from hypothermia.
Learn more about Medical research here
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Answer:
A or 3 (Wether wich one is on your test) I TOOK THE TEST
Ill take brainliest
100% Verified
Explanation:
i took the test :D
