Answer:
Option D, Number of limbs
Explanation:
Options for the question
a. Birth weight
b. Hair color
c. Number of offspring
d. Number of limbs
Solution
Variation within a species is caused due to genetic differences governed by varying allele frequencies and duet to environmental factors that somewhere effect the expression of the genetic potentials thereby causing phenotypic variation.
Number of limbs is a physical characteristics, very unlikely governed by genetic variation. While factors such as hair color (grey, black, white etc.), height (tall, short, medium) etc. are governed by genetic variation as a result of which they have several phenotypic variations.
Hence, option D is correct
Answer: B voltage-gated potassium channels
Explanation:#
Tetraethylammonium is a pH- potassium channel blocker.
Therefore, it prevents the escape of potassium ions from the axoplasm, which makes it ( axoplam) positive from the rise in potassium ions concentration , since potassium ion is positive charged and intracellular ion . This initiate repolarization which returns to membrane state potential.
Since it is pH -potassium ion blocker; it does not affect the voltage-gated sodium ion channels, so action potential can occur. But after the sodium gated channels were closed,action potential drops but the concentration of potassium rises because :
1. They are naturally intracellular ions
2. They cannot leave the axoplasm because the channels has been shut. Therefore this stabilizes the membrane potential
Becuase there red blood cells become larger when stuck with sickle cell, thus causing blood clots, thus stopping the spread of malaria to the vital organs, and killing the victim.
Muscle tissue helps you move.
Answer:
the basic unit of a chemical element.
Explanation:
