(a) The certificate of incorporation may contain provisions specifying either or both of the following:

(1) That the proportion of directors that shall constitute a quorum for the transaction of business or of any specified item of business shall be greater than the proportion prescribed by this chapter in the absence of such provision.

(2) That the proportion of votes of directors that shall be necessary for the transaction of business or of any specified item of business shall be greater than the proportion prescribed by this chapter in the absence of such provision.

(b) (1) An amendment of the certificate of incorporation which changes or strikes out a provision permitted by this section shall be authorized at a meeting of shareholders by (A) (i) for any corporation in existence on the effective date of subparagraph (2) of this paragraph, two-thirds of the votes of all outstanding shares entitled to vote thereon, and (ii) for any corporation in existence on the effective date of this clause the certificate of incorporation of which expressly provides such and for any corporation incorporated after the effective date of subparagraph (2) of this paragraph, a majority of the votes of all outstanding shares entitled to vote thereon or (B) in either case, such greater proportion of votes of shares, or votes of a class or series of shares, as may be provided specifically in the certificate of incorporation for changing or striking out a provision permitted by this section.

(2) Any corporation may adopt an amendment of the certificate of incorporation in accordance with any applicable clause or subclause of subparagraph (1) of this paragraph to provide that any further amendment of the certificate of incorporation that changes or strikes out a provision permitted by this section shall be authorized at a meeting of the shareholders by a specified proportion of the votes of the shares, or particular class or series of shares, entitled to vote thereon, provided that such proportion may not be less than a majority.