Answer:
The skeletal system is vital in supporting the immune system because : Bones contain marrow, a porous material which creates both white and red blood cells. This replenishment of cells allows the body to fight and expel harmful bacteria, environmental toxins, foreign material e.t.c.
The white blood cells formed by the marrow are instrumental in isolating and destroying harmful particles (either on the site or in lymph nodes), or transporting them to the kidneys or bowels for excretion.
NOTE : Some people have marrow disorders which prevent their marrow from forming new cells; this is caused most often by cancer. Today, it is possible to transplant marrow from a healthy individual to a sick patient, and so help their bone marrow form new white and red blood cells to fight their sickness.
I hope it helps :)
Answer:
It's impossible to predict the phenotype of the offspring by only observing the parents because DNA from their grandparents can affect the offspring as well.
Explanation:
DNA is combined from the parents to create offspring. When that offspring reproduces their children not only possess DNA from their parents but from their grandparents as well. Mixing together two separate DNA's from two different family trees can result in rare genetic mutations which results in the offspring looking different from their parents but showing resemblance to their grandparents. This is why you have to look at the phenotypes of more then just the two parents because there are more possibilities, including what their grandparents looked like.
Answer:
approximately 4.5 billion years ago
Explanation:
A mutation which occurs when a base is introduced into the DNA sequence before transcription begins will lead to frame-shift of a single base on the DNA sequence resulting in nonfunctional protein from the transcribed mRNA.
Explanation:
This change either through addition or deletion of a single base in the codon sequences of the DNA will modify the amino acid codes and will result in nonfunctional proteins after transcription.
This mutation will just result in change of a single base, i.e., it would be added either to the enhancer region or the silencer region of the sequence before the promoter which initiates transcription.
The mRNA produced due to mutated DNA sequence after the deletion or insertion point will be read as out of frame thus resulting in nonsense protein.
Antibiotic resistance occurs when bacteria change in some way that reduces or eliminates the effectiveness of drugs, chemicals, or other agents designed to cure or prevent infections. The bacteria survive and continue to multiply causing more harm. Bacteria can do this through several mechanisms. (By google)
