Flattened membranous sacs; packages proteins into vesicles for secretion, modifies proteins that become part of cell membranes, and packages enzymes into lysosomes. Also called Golgi complex or Golgi body.
Answer:
Sub-threshold
Explanation:
If the stimulus is too small to generate the action potential, it is considered as subthreshold stimulus. Subthreshold stimulus causes the opening of small number of sodium channel i.e. not enough to generate action potential because action potential is generated by complete reversal of membrane polarity. Slight depolarization is caused by subthreshold stimulus by the opening of inadequate number of sodium channel but its magnitude is not enough to reach the threshold voltage. Consequently the action potential is not generated.
The response produced by subthreshold stimulus is called as local response or local depolarization because it could not travel further. The minimum stimulus required to generate the action potential is call as threshold stimulus and stimulus greater than threshold stimulus is called as suprathreshold stimulus. It changes the frequency of generated action potential.
Answer:
1) To form a multicellular organism, a zygote must divide into 16 cells which produces ball structure called a morula. After that, morula is converted into a structure called blastula.
2) Adult stem cells are responsible for the maintenance of tissues and repair the damage tissues in the body. It is also called somatic stem tissue. It increase in number through cell division.
(A nebula)
is a cloud of gas (hydrogen) and dust in space. Nebulae are the birthplace biths. There are different types of nebula. An Emission Nebubla such as Orion nebula, glows brightly because the gas in it is energised by the stars that have already formed within it.
(A star)
is a luminous globe of gas producing its own heat and light by nuclear reactions (nuclear fusion). They are born from nebulae and consist mostly of hydrogen and helium gas.
(red giant)
This is a large bright star with a cool surface. It is formed during the later stages of the evolution of a star like the Sun, as it runs
out of hydrogen fuel at its centre.
(red dwarf)
These are very cool, faint and small stars, approximately one tenth the mass and diameter of the Sun. They burn very slowly and have estimated lifetimes of 100 billion years.
(white dwarf)
This is very small, hot star, the last stage in the life cycle of a star like the Sun. White dwarfs have a mass similar to that of the Sun, but only 1% of the Sun's diameter; approximately the diameter of the Earth.
(Black holes)
are believed to form from massive stars at the end of their life times. The gravitational pull in a black hole is so great that nothing can escape from it, not even light. The density of matter in a black hole cannot be measured.
Answer:
C.. A hypothesis is a possible, testable explanation for a scientific question
