The heart of a fish is:

Which one of the following is the molecular formula of a tertiary amine?

The pressure and density of a given mass of a diatomic gas $\left(\gamma = \frac{7}{5}\right)$ change adiabatically from $(P, d)$ to $(P^{\prime}, d^{\prime})$. If $\frac{d^{\prime}}{d} = 32$,then $\frac{P^{\prime}}{P}$ is $(\gamma = \text{ratio of specific heats})$

Which of the following organisms possesses a cell wall made of peptidoglycan?

Cardiac output is determined by which of the following?

Fraunhofer lines are produced by the absorption of light in