Lethal alleles (also referred to as lethal genes or lethal) are alleles that cause the death of the organism that carry them. They are usually a result of mutations in genes that are essential to growth or development. Lethal alleles may be recessive, dominant, or conditional depending on the gene or genes involved. Lethal alleles can cause death of an organism prenatally or any time after birth, though they commonly manifest early in develop
D. Proteins help control substances by making trans-membrane channels.
B. total time and total distance
Mercury's seasons are difficult to determine. This is because it has virtually no tilt (0.03 degrees), but a highly elliptic orbit. ... Mercury also has a bizarre rotation, spinning three times (every 53 Earth days) over two rotations around the Sun, making it impossible to tell when one season begins and one ends.
The right answer is A. sismic waves.
Seismic waves correspond to elastic waves that propagate on the surface and inside our planet following an earthquake.
They appear when a starting impulse sets particles in motion, which in turn will move the material to their contact before returning to their original place. The generated phenomenon can then spread over tens, hundreds, even thousands of kilometers. Note that these waves can be generated artificially in seismic studies.
Like all waves, they can be reflected or refracted when they pass from one medium to another (for example between the mantle and the Earth's core).
