Answer:
the male gametophyte
Explanation:
Pollen grains are structures in the seed plants (spermatophytes) which contain vegetative cells but also reproductive cells - microgametophytes. Microgametophytes produce 2 male gametes or sperm cells. Vegetative cells produce pollen tube which is involved in the transfer of sperm cells to the ovule (female structure that forms female gametes). Pollen grains are different in shape, size and color, but all of them are enveloped with hard coat that has protective role.
The right answer is: voltage-gated channels
Ionic channels are membrane proteins that allow the selective passage of the cell membrane by ions (Na +, Ca2 +, K +, Cl-, ...) following the electrochemical gradients. They play a vital role in cellular excitability, triggering and propagation of action potential. They intervene in the coupling excitation-contraction and excitation-secretion. Ion channel selectivity is based on the adequacy of ion size and charges with the structure and amino acid sequence of the channels.
Among these channels, there are voltage-gated channels.
These are ion channels whose opening is activated by the membrane potential.
These dependent volumetric channels are characterized:
- by the selectivity of the ions (Ca2 +, Na +, K +, Cl-, ...)
- by their conductance
- by their activation domain (significant depolarization to low)
- by their kinetics of inactivation (slow, fast or transient)
Answer:
The options
A. Comma splice
B. Fused sentence
The CORRECT ANSWER IS A.
A. Comma splice
Explanation:
In English grammar, a comma splice can also be called a comma fault.
It occurs when the comma is uesd to join two independent clauses or complete sentences with a comma and no conjunction.
This form of writing is often used in literary writing to portrait a certain mood of informality.
A comma splices can be corrected in three varying ways such as:
-using a coordinating conjunction (for, and, nor, but, or, yet, so) to come right after the comma.
-converting the comma to semicolon.
-converting the comma to a period
Answer:
I believe it is B They occur when the temperature is below freezing.
Explanation:
