Answer:
a.Many mitochondrial genes resemble proteobacteria genes, while the genes in the chloroplast resemble genes found in some photosynthetic bacteria.
c.Mitochondria and chloroplasts both have their own circular DNA and 70S ribosomes that are similar to those found in bacteria.
d.Mitochondria and chloroplasts replicate by a process similar to mitosis.
Explanation:
Endosymbiotic theory states that mitochondria and chloroplast which are organelles of eukaryotic cells were once independently living micro-organisms but with due course of time eukaryotic cells engulfed them and they become an integral part of these eukaryotic cells.
The resemblance between mitochondrial genes with those of proteobacteria and chloroplast genes with photosynthetic bacteria strongly support endosymbiotic theory. Apart from this, the presence of their own DNA that too circular just like prokaryotic microbes and 70 S ribosomes also support this theory. Also just like prokaryotic cells, before cell division mitochondria and chloroplasts undergo replication by means of a process known as binary fission.
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:
c. increase the release of digestive enzymes and bile
Explanation:
Secretin and cholecystokinin are hormones produced in the duodenal region of the small intestine. They are both involved in the release of digestive enzymes and bile.
Secretin is actively involved in controlling the pH of the chyme when it enters the duodenum from the stomach. It does so by inhibiting the release of gastric acid from the parietal cells in the stomach. Secretin induces the release of sodium bicarbonate ions from the pancreas which help to increase the pH of the chyme. This hormone also stimulates the secretion of bile.
Cholecystokinin (CCK) stimulates the contraction of the gallbladder and the release of bile into the duodenum. CCK also acts on the pancreas, stimulating it to produce pancreatic juices for digestion.
Well, MOST pathogenic bacteria is harmless, but SOME could cause death, like tuberculosis, but just in case you would want to mark the answer as, "True".
I hope I helped! =D