Fill in the blank.
1. The two strands of the DNA double helix are held together by
base pairs.
2. DNA replication, each strand of DNA serves as a __ _for
DNA
3. In gene expression, DNA is used as a template to make
template to make a polypeptide.

1.hydrogen

2.template

3.mRNA

4.recombination

5.DNA and RNA are both made up of nucleotides. RNA is comprised of adenine, uracil, guanine, and cytosine. DNA is made up of adenine, thymine, guanine, and cytosine. DNA is a double-stranded chain of nucleotides comprised of base pairs that form a double helix. RNA is often a single-stranded chain of nucleotides.

6.The central dogma states that DNA contains the genetic code needed to make proteins—a process known as gene expression. Transcription and translation are the two steps involved in gene expression. In transcription, the DNA code is turned into RNA. In translation, the RNA sequence provides instructions to the cellular machinery to manufacture polypeptides, which become proteins.

7.Replication is the duplication of DNA, and it is important because, in cell division, each daughter cell must contain an exact copy of the original cell's DNA, since DNA contains the instructions required to make all of the cell's tissues. Recombination is the natural process for genetic sequences in a chromosome or between chromosomes to exchange genetic information. Recombination is important in nature because it produces genetic variations that may be preserved because of natural selection. Recombination also can be used in the laboratory to combine the genetic code of two different organisms.

Explanation:

PENNFOSTER

answer: land bridge theory. land bridge theory held that shifting portions of dry land explained the finding of identical species on different continents. plate tectonic theory eventually eliminated the land bridge theory.