All practice questions

Match each chemical reaction or process involving alkanoic acids, esters, fats, or oils on the left with its corresponding chemical outcome or product description on the right.

An ecologist conducting a field study along a coastal cliff needs to measure both the angle of slope of the terrain and the atmospheric pressure at different elevations. Which pair of ecological instruments should the ecologist select for these measurements?

During humid nights when atmospheric humidity is high and transpiration is minimal, liquid water droplets are observed exuding from leaf margins of herbaceous plants. Which transport mechanism and plant structure account for this liquid exudation?

A microscopic unicellular organism isolated from a freshwater pond exhibits mixotrophic nutrition: it photosynthesizes in sunlight using chloroplasts, but absorbs organic nutrients heterotrophically when kept in the dark. It moves by means of a single flagellum and lacks a cellulose cell wall, possessing a flexible proteinaceous pellicle beneath its plasma membrane instead. Which of the following protists is described, and what is its primary carbohydrate storage product?

Match each organism in Column I with its corresponding structure used for gaseous exchange in Column II.

When purified and isolated outside a host organism, viral particles can form crystals and exhibit no measurable respiration or energy production. Which of the following features explains why viruses are metabolically inert outside a host cell?

An organic compound $X$ with the molecular formula $\text{C}_4\text{H}_{10}\text{O}$ resists oxidation when treated with acidified potassium dichromate(VI) ($\text{K}_2\text{Cr}_2\text{O}_7/\text{H}^+$). When compound $X$ is heated with concentrated tetraoxosulfate(VI) acid ($\text{H}_2\text{SO}_4$) at $170^\circ\text{C}$, it undergoes dehydration to produce a major organic product $Y$. What is the IUPAC name of compound $Y$?

An investigation into the excretory mechanisms of four diverse invertebrate species revealed distinct structures for nitrogenous waste elimination:
- Structure P: Uses ciliated flame cells to propel fluid through a network of branching tubules.
- Structure Q: Relies on ciliated funnels (nephrostomes) opening into the coelom for fluid filtration and tubular reabsorption.
- Structure R: Consists of blind-ending tubules lying free in the hemolymph that actively transport nitrogenous wastes as uric acid into the hindgut.
- Structure S: Relies entirely on simple diffusion across the general body wall without specialized excretory organs.

Which of the following correctly matches excretory structures P, Q, R, and S with their respective animal representatives?

During the complete aerobic oxidation of one molecule of glucose in a cell, a total of 10 $NADH$ and 2 $FADH_2$ reduced coenzymes are generated across glycolysis, the link reaction, and the Krebs cycle. Assuming that each $NADH$ yields 3 ATP molecules and each $FADH_2$ yields 2 ATP molecules during electron transport, what is the net number of ATP molecules produced specifically through oxidative phosphorylation?

A farmer notices a rapid loss of soil nitrogen in a waterlogged maize field that had been treated with ammonium-based fertilizer. Soil analysis confirms that ammonium ions ($\text{NH}_4^+$) were first oxidized to nitrites ($\text{NO}_2^-$), then further oxidized to nitrates ($\text{NO}_3^-$), which were subsequently reduced to gaseous nitrogen ($\text{N}_2$) under anaerobic conditions. Which sequence of bacteria is sequentially responsible for these three specific biochemical transformations?

Which of the following excretory structures is characteristic of flatworms such as *Planaria*?

In a savanna ecosystem, primary producers have a gross primary productivity (GPP) of $20{}000\text{ kcal m}^{-2}\text{ yr}^{-1}$, but consume $50\%$ of this energy through autotrophic cellular respiration ($R_A$). Assuming a constant ecological efficiency of $10\%$ for energy transfer between consecutive trophic levels, what is the total amount of energy per square meter per year available to tertiary consumers?

Calculate the quantity of electricity, in Coulombs, required to deposit $0.108\text{ g}$ of silver at the cathode during the electrolysis of silver trioxonitrate(V) solution. ($\text{Ag} = 108\text{ g/mol}$, $1\text{ F} = 96,500\text{ C/mol}$)

Arrange the following stages of sexual reproduction (zygospore formation) in the bread mould *Rhizopus* in the correct chronological sequence from start to finish:

During the electrolysis of dilute tetraoxosulfate(VI) acid, a steady current of $2.50\text{ A}$ is passed through the electrolyte for $1930\text{ seconds}$. What volume of hydrogen gas, measured at STP, is liberated at the cathode?

$[1\text{ Faraday} = 96500\text{ C mol}^{-1}, \text{Molar volume of gas at STP} = 22.4\text{ dm}^3\text{mol}^{-1}]$

An aquatic unicellular protist possessing a rigid cellulose cell wall, two equal anterior flagella, a cup-shaped chloroplast with a pyrenoid, and a prominent eyespot is transferred from freshwater to a hypertonic saline medium under continuous illumination. Which of the following responses describes the physiological and subcellular changes occurring in this organism?

A mixture of $50\text{ cm}^3$ of carbon(II) oxide and $30\text{ cm}^3$ of oxygen was ignited in an eudiometer tube to complete reaction. After cooling to room temperature and pressure, the resulting gas mixture was passed through concentrated potassium hydroxide solution. What is the volume of the residual gas remaining?

Cyanobacteria perform oxygenic photosynthesis within membrane-bound chloroplasts, distinguishing them structurally from bacterial groups in Kingdom Monera.

Match each ecological concept or trophic entity on the left with its corresponding characteristic regarding energy flow and pyramid structure on the right.