Solar System[a] is the gravitationallybound system of the Sun and the objects that orbit it, either directly or indirectly,[b] including the eight planets and five dwarf planets as defined by the International Astronomical Union (IAU). Of the objects that orbit the Sun directly, the largest eight are the planets,[c]with the remainder being smaller objects, such as dwarf planets and small Solar System bodies. Of the objects that orbit the Sun indirectly—the moons—two are larger than the smallest planet, Mercury.[d]
Solar System
The Sun and planets of the Solar System
(distances not to scale)
Age4.568 billion yearsLocation
Local Interstellar Cloud, Local Bubble,
Orion–Cygnus Arm, Milky Way
System mass1.0014 Solar massesNearest star
Proxima Centauri (4.25ly)
Alpha Centauri (4.37 ly)
Nearest knownplanetary systemProxima Centaurisystem (4.25 ly)Semi-major axis of outer known planet (Neptune)30.10 AU (4.503 billion km)Distance to Kuiper cliff50 AU
Populations
Stars1 (Sun)Known planets
8 (Mercury
Venus
Earth
Mars
Jupiter
Saturn
Uranus
Neptune)
Known dwarf planets
Possibly several hundred;[1]
five currently recognized by the IAU
(Ceres
Pluto
Haumea
Makemake
Eris)
Known natural satellites
525
(185 planetary[2]
347 minor planetary[3])
Known minor planets778,897 (as of 2018-06-21)[4]Known comets4,017 (as of 2018-06-21)[4]Identified rounded satellites19Invariable-to-galactic plane inclination60.19° (ecliptic)Distance to Galactic Center27,000 ± 1,000 lyOrbital speed220 km/sOrbital period225–250 MyrSpectral typeG2VFrost line≈5 AU[5]Distance to heliopause≈120 AUHill sphere radius≈1–3 ly
The Solar System formed 4.6 billion years agofrom the gravitational collapse of a giant interstellar molecular cloud. The vast majority of the system's mass is in the Sun, with the majority of the remaining mass contained in Jupiter. The four smaller inner planets, Mercury, Venus, Earth and Mars, are terrestrial planets, being primarily composed of rock and metal. The four outer planets are giant planets, being substantially more massive than the terrestrials. The two largest, Jupiterand Saturn, are gas giants, being composed mainly of hydrogen and helium; the two outermost planets, Uranus and Neptune, are ice giants, being composed mostly of substances with relatively high melting points compared with hydrogen and helium, called volatiles, such as water, ammonia and methane. All eight planets have almost circular orbits that lie within a nearly flat disc called the ecliptic.
Answer:
Prokaryotic cell-- no organelles, no membrane.
Eukaryotic cell -- Have organelles and membrane.
Explanation:
For the model of prokaryotic cell, we construct the model by removing organelles from the cell whereas in the eukaryotic cell, we add the organelles because in eukaryotic organisms, organelles are present in the cell that performs specific function. In the model of prokaryotic cell, we have to remove membrane around the nucleus whereas membrane president around the nucleus. In the prokaryotic cell, nucleus is not visible while on the other hand, in eukaryotic cell, the nucleus is visible and can be differentiate from other organelles.
Answer:
A) increasing frequency of action potentials only.
Explanation:
If the muscle fibers begin the contraction with the sarcomere too elongated, the thick and thin filaments would be barely overlapping, forming few crossed bridges. On the contrary, if the sarcomere is too shortened so that the thick filaments reach the z-disks, the myosin is unable to find new fixation sites for cross-bridge formation and the tension decreases rapidly.
But to better understand how the contraction force increases, it should be noted that a single contraction does not represent the maximum force that a muscle fiber can develop. <u>The force generated by the contraction of a muscle fiber is increased, increasing the frequency with which the action potentials of the muscle stimulate said fiber,</u> that is to say that the nervous system controls part of this.
A potential muscular type action lasts between 1 and 3 ms. While muscle contraction can last 100 ms. If the repeated action potentials are separated by prolonged intervals of time, the muscle fiber has time to fully relax between the stimuli. If the action potentials continue to stimulate muscle fiber repeatedly at short intervals (high frequency), the relaxation between contractions decreases until the muscle fiber achieves a state of maximum contraction known as tetanus.
bacteria can live in hotter and colder temperatures than humans but they do best in a warm moist protein-rich environment that is pH neutral or slightly acidic
The best way to determine this would be to determine the percentage of offspring that survived. So for example, if 900 offspring survived out of 1000 seeds, which is a 90% chance, then this can be considered successful or non successful in comparison to other trials.<span />