Answer:
The correct answer is option A. "Line spectra".
Explanation:
Line spectra is a method that is used to determine the temperature of a star. Line spectra is based on the principle that, depending on the temperature of a star, a line is traced which is compared to the continuum temperature that could either generate a emission (hotter) or absorption (colder) line. A spectrum of lines depending on the temperature have been established under the code OBAFGKM, where O is the hottest an M is coldest.
Answer:
(1)
Accepted theories may be modified or overturned as new evidence and perspective emerges. Scientists are likely to accept a new or modified theory if it explains everything the old theory did and more.
which is c
(2)
Bias is a disproportionate weight in favor of or against an idea or thing, usually in a way that is closed-minded, prejudicial, or unfair. Biases can be innate or learned. People may develop biases for or against an individual, a group, or a belief. In science and engineering, a bias is a systematic error. Wikipedia
which is c
(3)
a balance achieved between two desirable but incompatible features; a compromise.
"a trade-off between objectivity and relevance"
which is d or c
(4)
D. testable
Answer: A, B, and C are correct.
Polar attractions are (a) forces between atoms of partial charges.(b) weaker than covalent bond.(c) they are numerous.
Explanation:
Polar attractions take place between atoms with partial charges. They are weaker than covalent bond and numerous of them occur in the living cells. They can form between H and other electronegative atoms like oxygen provided they have strong partial charges.
Answer:
The myosin filament or more precisely the myosin head can now bind to the actin forming the cross bridges followed by a power stroke during which actin slides over myosin.
Explanation:
The muscle contraction can be explained by sliding filament theory bu Huxley and Huxley. The two muscle proteins which take part in muscle contraction are myosin and actin.
Myosin: It is a hexameric protein. Each monomer is called meromyosin. Each meromyosin has two important parts, a globular head with a short arm and a tail. The head forms cross bridges with the actin filament. Myosin head acts as ATPase enzyme. When ATP binds, head acts as enzyme hydrolyzing the ATP to produce energy. The head also has the site for binding of actin.
Actin filament: It contains three proteins, filamentous actin, tropomyosin and troponin. Filamentous actin contains active site for myosin binding but at rest, tropmyosin covers the myosin binding site. This prevents the cross bridge formation. Tropomyosin are held in place by troponin molecules.
When calcium is available, the binding of calcium to a TpC sub-unit of troponin causes the shifting of tropomyosin-troponin complex. Now actin can attach to myosin head and slide over myosin.
The actin filaments slide over the myosin filament by the the formation of cross bridges and during this process the I-band gets reduced whereas the A band remain the same. The lengths of actin and myosin filaments remain unchanged.
Answer: everything but air, rocks, and water are made up of cells
Explanation:
