Exam 13: Early Life Forms and the Viruses

Bacteria can exchange genes with other bacteria by a method called ____.

Humans acquire their first microorganisms during ____.

Protists that are part of a(n)_____ are integrated with other cells, but remain self-sufficient.

Ciliates, such as Paramecium , are likely to be found in ____ or in the gut of mammalian grazers where they aid in the digestion of _____.

 _____, which probably evolved from infoldings of the plasma membrane, first appear in the fossil record about 1.8 million years ago.

The fusion of gametes of malaria-causing Plasmodium takes place ____.

​​ Scientists hypothesize that ____ served as a primitive template for forming polymer chains from organic subunits, such as amino acids.

____ may have been the ancestors of cellular life.

Two researchers suggested in the 1960s that ____ may have been the first informational molecule.

____ bacteria are found inside the roots of legumes, where they receive _____ from the host plant.

The pathway on the left is named for what is happening in the figure labeled with letter ____.

____ are likely to provide hints about the earth's early atmosphere.

The earliest cells most likely ____.

DNA is more stable than RNA for storing genetic information because ____.