The defecation reflex involves two postive feedback loops. these loops are the stretch receptors in the rectal walls and the sacral parasympathetic system. Defecation reflex empties the rectum by peristaltic movements push fecal matter from the sigmoid colon into the rectum. Then this distension of the rectal walls stimulates stretch receptors which results in defecation.
Answer:
a.
Explanation:
The slight positive charges on the hydrogen atoms in a water molecule attract the slight negative charges on the oxygen atoms of other water molecules. This tiny force of attraction is called a hydrogen bond.
I think its D but I'm not sure
Answer: Transcription - A
Explanation:
This problem is talking about the lac operon and the gene expression of lac operon. If the gene is turned off, then transcription, the generation of mRNA won't occur.