Parietal cells of the gastric glands in the stomach produce

HCL and intrinsic factor

Explanation:

The oxyntic cells/ delomorphous cells also called as parietal cells. The cells are present in the gastric glands the fundus lining and cardia. These  parietal cells are the epithelial cells. The cells secretes intrinsic factor and HCL (hydrochloric acid).

The hydrochloric acid secreted helps in converting inactive pepsinogen to active enzyme pepsin. This helps to break bond between amino acids. This process is called proteolysis. The intrinsic factor helps in vitamin B12 absorption from the intestine and absence of this factor is responsible for pernicious anemia.  

2000 ants per square meters.

Explanation:

The population density, D, of a population can be calculated by dividing the total number of individuals by the area covered by that population. That is;

D = N/A

Where;

D = population density

N = population of individual organism

A = area covered (m²)

According to this question, a population of 6000 ants lives inside a dead log that measures 3 square meters. Hence, N = 6000 ants, and A = 3m²

Therefore, the population density (D) = 6000/3

= 2000

The population density is 2000 ants/square meter.