What does the cell wall of algae consist of?

The function $f: R \rightarrow R$ is defined by $f(x) = \cos^2 x + \sin^4 x$ for $x \in R$. Then the range $f(R)$ is equal to

At $20^{\circ}C$,the concentration of $Ag^{+}$ ions in a saturated solution of $Ag_2CrO_4$ is $1.5 \times 10^{-4} \ mol/L$. The solubility product $(K_{sp})$ of $Ag_2CrO_4$ at $20^{\circ}C$ is:

Two loops $P$ and $Q$ are made from a uniform wire. The radii of $P$ and $Q$ are $r_1$ and $r_2$ respectively,and their moments of inertia are $I_1$ and $I_2$ respectively. If $\frac{I_2}{I_1} = 4$,then $\frac{r_2}{r_1}$ equals:

When two species of different genealogy come to resemble each other as a result of adaptation,the phenomenon is termed as

Which of the following vitamins is water-soluble?