There isn't a meaning to life you have to figure it out for yourself. everyone is different so you'll have a different answers than anyone else
Convection currents, C! The plates move in a cycle called a convection cell that forms when warm material rise, cool, and even sink.
Answer:
1) In eukaryotic flagella, the fibers that slide past one another due to the activity of dynein proteins are microtubules.
2) Many cell organelles, most notably the nucleus, are anchored by intermediate filaments which are assembled from a diverse class of proteins.
3) Centrosomes are sites where protein dimers assemble into microtubules.
4) The extension of pseudopodia in amoeba is due to the regulated assembly and destruction of microfilaments.
5) The only cytoskeletal fibers not associated with intracellular movement or whole cell locomotion are the intermediate filaments.
6) During muscle contractions, myosin motor proteins move across tracks of microfilaments.
Explanation:
The cytoskeleton is a very important element of the cell, and is composed of three different structures: microtubules, intermediate filaments, and microfilaments.
<u>Microtubules</u> are structures in the shape of hollow tubes that <u>give shape to the cell</u>. Microtubules also participate in cell motility by <u>providing a route</u> for the organelles to move through.
Intermediate filaments are the only ones that do not participate in cell motility: their main function is to <u>provide mechanical support for the plasma membrane</u>.
Microfilaments are a key component in <u>cell motility</u>, and also associate with myosin (a protein) to produce <u>muscle contraction</u>. Microfilaments also give the cell the ability to grow <u>pseudopods</u>.
Answer:
Mechanical Isolation
A snail with a flat disc-like shell
will not be able to mate with a
snail having a conical shell.
The reproductive organs of
male bush babies do not
match with the reproductive
organs of females of other
bush baby species
Behavioral Isolation
The mating call of a cricket is not
recognized by a cricket of other
species.
The signals sent by a male firefly
are not recognized by the female
firefly of other species.
Explanation:
Mechanical isolation occurs in the scenario where two organisms are willing to mate but cannot do so due to the physical challenges. As in the case of snail a flat disk and a conical disk snail are willing to mate but physical barriers restrict them in doing so.
The same case is with the male and female bush babies where the difference in reproductive organs does not allow them to mate.
Behavioral isolation represents a scenario where two organisms are unaware of mating rituals, season, pattern or signals of each other and hence cannot mate.
For example – male and female cricket do not recognize the mating call of each other. Likewise male and female firefly is also not able to understand each other’s mating signal.
Type of cell division that results in two daughter cells each having the same number and kind of chromosomes as the parent nucleus, typical of ordinary tissue growth.
