It is C as to have freckles you have to have a dominant and recessive gene (can be worked out using a punnett square) as the child has 50% of not having freckles like his dad or 50% having freckles like his mom.
male genes(homozygous recessive)
f f
female F Ff Ff
genes
f ff ff
so ff is not having freckles and being homozygous recessive, or Ff having freckles and being heterozygous.
So the child is heterozygous so C
Answer:
If Clark had no ions in his nervous system, he would not be able to generate an action potentials.
Explanation:
An action potential occurs when a stimulus causes sodium channels to open in a neuron. Sodium floods in, making the inside of the cell more negative and the outside more positive. This is known as depolarization. Then, the Potassium channels open to allow Potassium out (Repolarization). A few too many K+ ions will leave the cell (Hyperpolarization), and finally, the Sodium-Potassium pump will bring the cell back to resting potential.
As you can see, the Sodium and Potassium ions are <em>essential</em> to action potentials in the nervous system. If Clark had no ions in his system, he would not be able to send any action potentials at all.
All are aspects of antibiotics resistance in bacteria.
• overuse of antibiotics in humans
• bacteria can reproduce so quickly
• any use of antibiotics will select for resistant bacteria
• overuse of antibiotics in livestock
