Question

there are four steps in bacterial conjugation. the second step is missing in this list.

1. special sex pilus connects two cells.

2.

1. each cell makes a complementary dna strand.
2. the cells separate.

which is the missing step for the process of conjugation described?
two new, identical cells are produced.
the cell membrane elongates and pinches off.
some dna moves from one cell to another.
a dna molecule attaches to the cell membrane.

Explanation:

Bacterial conjugation is a process where genetic material is transferred between bacterial cells. After the sex pilus connects the two cells (step 1), the next logical step in the transfer of genetic material (which is DNA) would be for some DNA to move from one cell to another. Option 1 (two new, identical cells are produced) is more related to binary fission (a form of asexual reproduction in bacteria, not conjugation). Option 2 (the cell membrane elongates and pinches off) is also related to binary fission. Option 4 (a DNA molecule attaches to the cell membrane) is not the typical step in the sequence of bacterial conjugation after the pilus has connected the cells. In conjugation, once the connection is made via the sex pilus, DNA transfer (from donor to recipient cell) occurs before the complementary DNA strand synthesis (step 3 in the given list).

Answer:

Some DNA moves from one cell to another.