Nhận biết (M1)

Vertical gene transfer involves the transmission of genetic material from a parent to offspring; horizontal gene transfer, on the other hand, involves the exchange of genetic material between organisms not in a parent-offspring relationship. While horizontal gene transfer is common among prokaryotes—single-celled organisms such as the bacteria Brevundimonas diminuta and Lactococcus lactis—it has rarely been observed among eukaryotes (typically multicellular organisms). However, new studies suggest that horizontal gene transfer is more common in eukaryotes than originally thought.

Which choice best states the function of the underlined sentence in the text as a whole?

• A.

  It compares the frequencies with which horizontal gene transfer has been detected in two categories of organisms.

• B.

  It implies that a common perception of horizontal gene transfer may be inaccurate.

• C.

  It argues that a particular direction of research concerning horizontal gene transfer is likely to be fruitless.

• D.

  It indicates a distinction between horizontal gene transfer and vertical gene transfer.