In a photosystem,the antennae complex includes all pigments except:

If $a > 0$ and $b^2 - 4ac = 0$,then the curve $y = ax^2 + bx + c$

Three non-zero non-collinear vectors $\vec{a}, \vec{b}$ and $\vec{c}$ are such that $\vec{a}+3\vec{b}$ is collinear with $\vec{c}$,and $3\vec{b}+2\vec{c}$ is collinear with $\vec{a}$. Then $\vec{a}+3\vec{b}+2\vec{c}$ equals to

The $pH$ of blood does not appreciably change by a small addition of an acid or a base because blood

The value of $\lambda$ with $|\lambda| < 16$ such that $2 x^2 - 10 x y + 12 y^2 + 5 x + \lambda y - 3 = 0$ represents a pair of straight lines,is

Bundle of His is a part of which one of the following organs in humans?