What has two fold rotational symmetry?

What has two fold rotational symmetry?

The situation in which the two DNA strands of a duplex have the same base sequence when read with the same polarity. For example, the EcoRI (q.v.) endonuclease recognizes a DNA segment six base pairs long that has twofold rotational symmetry.

What is palindrome symmetry?

Palindromes that read the same in both directions of the same strand, ie, proper (or true), palindromes also are known. These sequences possess a mirror symmetry, for example, ATGAGTA.

What does an N fold symmetry correspond to?

Rotational symmetry of order n, also called n-fold rotational symmetry, or discrete rotational symmetry of the nth order, with respect to a particular point (in 2D) or axis (in 3D) means that rotation by an angle of 360°/n (180°, 120°, 90°, 72°, 60°, 51 3⁄7°, etc.) does not change the object.

Does an equilateral triangle have two fold rotational symmetry?

Properties: a. An equilateral triangle has 3-fold rotational symmetry.

What is the angle of rotation for a five fold symmetry?

In fact, an n-sided regular polygon has n-fold symmetry. For example, a regular pentagon has 5-fold rotational symmetry and can be mapped upon itself through rotation by an angle of 2π/5.

Why are restriction enzyme sites called palindrome?

A palindromic sequence is the same backwards and forwards on both sides (see image below). This means that the enzyme recognizes the sequence no matter from which side the enzyme approaches the DNA. A palindromic sequence also increases the chance that both strands of DNA are cut.

Do restriction enzymes only recognize palindromic sequences?

This is a short DNA sequence (generally 4-8 nucleotide pairs) that an enzyme specifically recognizes. Most restriction enzymes recognize palindromic sequences, meaning that both strands of DNA will have the same sequence when read 5′ to 3′. For example, the sequence ATTGCAAT is palindromic.

What is order 2 rotational symmetry?

Rotational Symmetry and Order The order of symmetry is a number used to describe how many times the object will appear to be the same while rotating through 360°. If it only matches up twice, it is Order 2; if it matches the original shape three times, it is Order 3, and so on.

What symmetries does an equilateral triangle have?

An equilateral triangle has three lines of symmetry. It has rotational symmetry of order 3. It has three equal sides.