In 2012, scientists discovered that colonies of single-celled organisms can be found in high numbers in the human gut. Scientists are particularly concerned with the colonies that produce methane, as methane in the human gut can be linked to constipation and irritable bowel syndrome (IBS). The scientists can classify these colonies as belonging to the domain .

Archaebacteria

Explanation:

Carl Woese categorised the bacteria into two domains called the Archaebacteria and the Eubacteria.

The Archaebacteria is the group of bacteria which can survive in the extreme condition as they posses the characteristics of both the prokaryotes and some eukaryotes. The bacteria are known as the extremophiles.

In the given question, the bacteria which lives in the gut of the human uses methane gas and thus are known as the methanobacteria. These bacteria are considered the archaebacteria as they methane for survival.

Thus, Archaebacteria is correct.

he forelimbs below belong to four species that descended in a direct line from the ancestral mammal shown above. of the four descendants shown, which species most likely appeared earliest in evolutionary history?

in the year 2850, humans successfully colonized mars. the martian modules that were constructed could hold only a small population of people. it is now a century later, and the population on mars has grown to 600 people. of the current mars population, 45 people express the recessive phenotype for phenylketon- uria (pku) syndrome (pp genotype).

explanation: