Question

Of the three types of restriction enzymes, only type _____ restriction enzymes can recognize specific DNA sequences; these are the most commonly used restriction enzymes in biotechnology.

1) Type I
2) Type II
3) Type III
4) Type IV

Answer 1

Type II restriction enzymes are unique in their ability to specifically recognize and cleave DNA sequences, which is why they are predominantly used in biotechnology practices like cloning and DNA analysis.

Step-by-step explanation:

Of the three types of restriction enzymes, only type II restriction enzymes can recognize specific DNA sequences; these are the most commonly used restriction enzymes in biotechnology. Type II restriction enzymes are known for their ability to cleave DNA at specific recognition sites.

These sites are typically palindromic sequences, which read the same in the 5' to 3' direction on one DNA strand as in the 5' to 3' direction on the complementary strand.

An example is the restriction enzyme EcoRI, which recognizes the sequence 5'GAATTC 3' and makes a staggered cut between the G and A, resulting in "sticky ends". These enzymes are widely utilized in molecular biology for various applications like genetic engineering, molecular cloning, and DNA fingerprinting.

Answer 2

Type II restriction enzymes are the ones that recognize specific DNA sequences and are widely used in biotechnology for precise DNA cutting and recombinant DNA creation. They function by targeting palindromic sequences and often leave 'sticky ends' for cloning purposes. The correct answer to the provided question is option 2) Type II.

Step-by-step explanation:

Among the three types of restriction enzymes, Type II restriction enzymes are known to recognize specific DNA sequences and are the most commonly used enzymes in biotechnology. Type I and Type III have different functions or characteristics and do not have the specificity for DNA sequences that Type II enzymes possess. These Type II enzymes, such as EcoRI, cleave the DNA at specific recognition sites, which are usually palindromic sequences, meaning they read the same forward and backward on complementary DNA strands, and often leave “sticky ends” that can be used for the creation of recombinant DNA in various applications like gene cloning and DNA fingerprinting.

When working with DNA manipulations in biotechnology, the specific cutting by these enzymes is crucial. For example, the EcoRI enzyme recognizes the sequence 5'GAATTC 3' and makes a staggered cut to produce “sticky ends”. This ability to cut at specific locations allows for the isolation of specific genes or DNA segments for further use in cloning, analysis, or genetic engineering.

Therefore, for the question asked, the correct option in the final answer would be to choose only one option, which is option 2) Type II.