Biology Now Study Set 1

The two strands of a DNA molecule are held together by ________ bonds between their base pairs.

Along one side of a DNA molecule,the nucleotides are connected to each other by ________ bounds between ________.

Which of the following is NOT a base found in DNA?

What part of a nucleotide accounts for the genetic variation between individuals?

In a single strand of DNA,the total number of phosphate groups present is equal to the total number of ________ bases.

If a segment of double-stranded DNA has 20 percent adenine (A),how much of it is cytosine (C)?

When bases of DNA correctly bind to the complementary strand,

In a strand of double-stranded DNA,cytosine (C)will always be bound with

If one strand of DNA has the sequence CGATT,the sequence of the other strand of the same molecule will be

When looking at a single-stranded piece of DNA,

When examining the two complementary strands of nucleotides in one DNA molecule,it would be expected that the sum of ________ in one strand would be ________ the sum of the ________ in the other strand.

The sequence of DNA differs among individuals within a species.This is the reason for

The hereditary genetic material present in all living cells is

The order of the base pairs in a DNA molecule

The CRISPR-Cas9 system is made up of two guide ________ molecules and two Cas9 ________ molecules.

Once attached to the proper DNA sequence,Cas9 proteins found in the CRISPR-Cas9 system ________ both strands of DNA.

Targeting the pol gene in pig DNA works to remove the 62 porcine endogenous retrovirus (PERV)genes because the pol gene is typically ________ in all 62 copies of PERV genes and ________ in other pig genes.

The CRISPR-Cas9 complex cuts through both strands of DNA in two neighboring sites.The chromosome does not break apart because during normal repair processes,the DNA sequences between the cut sites are

Before using the CRISPR-Cas9 system to edit the pig genome,it is necessary to sequence the pig DNA to identify any copies of porcine endogenous retrovirus (PERV)DNA.Knowing the PERV DNA sequences will help researchers determine which ________ sequences to use as guides for the CRISPR-Cas9 complex.

Researchers used the CRISPR system to make 455 different cuts in the porcine endogenous retrovirus (PERV)pol genes in the pig genome.All of the PERV genes were inactivated in the pig embryos even though only 20 percent of the resulting mutations were larger than nine base pairs.The resulting mutations were successful at knocking out the PERV genes because