All practice questions

Match each mammalian reproductive cell or gland with its primary physiological function.

During selective reabsorption in the mammalian nephron, glucose and amino acids are completely reabsorbed back into the bloodstream from the glomerular filtrate. In which specific region of the nephron does this process primarily take place, and what structural feature enables it?

A commercial farm in Kaduna operates with fixed total resources of $10$ hectares of arable land and $120$ worker-hours of labor per day. Producing $1$ ton of maize requires $1$ hectare of land and $12$ worker-hours of labor. Producing $1$ ton of yams requires $0.5$ hectares of land and $20$ worker-hours of labor. Initially, the farm devotes all its resources to maximize maize production, harvesting $10$ tons of maize per day. If the farm owner decides to reallocate resources to produce $3$ tons of yams per day, what is the opportunity cost of this decision expressed in tons of maize foregone?

A commercial flour milling enterprise located in an industrial estate in Kaduna increases all of its production inputs—both capital and labor—by $100\%$. Due to internal managerial communication bottlenecks and operational delays, total output increases by only $65\%$. Concurrently, the regional government constructs a shared high-capacity grain silo and transport infrastructure hub that reduces raw material storage and freight costs for all milling firms operating in that industrial estate. Which of the following statements correctly categorizes the firm's internal production relationship and the cost benefit derived from the regional infrastructure?

An uncatalyzed endothermic reaction has a forward activation energy of $120\text{ kJ mol}^{-1}$ and an overall enthalpy change ($\Delta H$) of $+50\text{ kJ mol}^{-1}$. In the presence of a positive catalyst, the activation energy of the forward reaction is reduced by $40\text{ kJ mol}^{-1}$. What is the activation energy for the reverse reaction in the presence of the catalyst?

A gaseous hydrocarbon rapidly decolourizes bromine water in tetrachloromethane, but fails to form a precipitate when bubbled through an ammoniacal solution of silver nitrate. Which of the following hydrocarbons exhibits this chemical behavior?

A commercial farming enterprise in Oyo State uses its fixed land and labor resources to produce Cassava and Yam. The table below presents its monthly production possibility schedule:

What is the opportunity cost of increasing Yam production from $45$ bags to $80$ bags, expressed in bags of Cassava foregone?

An illuminated suspension of green algae undergoing steady-state photosynthesis was supplied with radioactively labeled carbon dioxide ($^{14}CO_2$). When the light source was abruptly turned off while maintaining the supply of $^{14}CO_2$, analysis revealed an immediate accumulation of glycerate-3-phosphate (PGA) alongside a rapid decline in ribulose 1,5-bisphosphate (RuBP). Which of the following physiological mechanisms explains why glycerate-3-phosphate accumulates in the absence of light?

A commercial bakery operating in a small community decides against dividing its production process into specialized sub-tasks because the local population buys only a small quantity of bread daily. Which factor is primarily responsible for limiting the practice of division of labor in this bakery?

Match each type of gene mutation or chromosomal aberration on the left with its corresponding description on the right.

The table below presents the utility schedule for a consumer consuming successive units of commodity $X$:

What is the marginal utility ($MU$) derived from consuming the $4^{\text{th}}$ unit of commodity $X$?

In a socialist or command economy, key economic decisions regarding production, resource allocation, and distribution are primarily made by which of the following?

A flour milling firm operating in an industrial zone in Ogun State increases all of its inputs of capital and labor by $100\%$, leading to a $150\%$ increase in total output. However, as multiple neighboring factories expand simultaneously in the same area, severe traffic congestion and municipal power shortages cause the firm's long-run average cost ($LRAC$) to increase. Which of the following correctly classifies the economic phenomena experienced by this firm?

In monohybrid inheritance experiments involving guinea pig coat color, where the allele for black fur ($B$) is completely dominant over the allele for white fur ($b$), match each specified parental cross or test cross scenario on the left with its corresponding phenotypic or genotypic outcome in the offspring on the right.

In a perfectly competitive market, an individual firm is considered a price taker because its output is so small relative to total market supply that it cannot influence the market price.

A sample of salivary amylase was kept in an ice bath at $0^\circ\text{C}$ for two hours and then mixed with a starch solution maintained at body temperature ($37^\circ\text{C}$). Which of the following best describes the outcome of this reaction?

During a field study of an intertidal mangrove swamp in Cross River State, a student used a $0.5\text{ m} \times 0.5\text{ m}$ quadrat frame to sample the periwinkle (*Tympanotonus fuscatus*) population. Across $10$ randomly placed quadrat throws, a total count of $180$ periwinkles was recorded. What is the estimated population density of *Tympanotonus fuscatus* per square metre in this habitat?

During gametogenesis, non-disjunction of chromosome 21 occurs specifically during Meiosis I. If all resulting gametes are subsequently fertilized by normal haploid gametes, what percentage of the produced zygotes will have trisomy 21?

In fruit flies (*Drosophila melanogaster*), grey body color ($B$) is dominant over black body color ($b$), and normal wing length ($V$) is dominant over vestigial wings ($v$). If two heterozygous grey-bodied, normal-winged flies ($BbVv$) are crossed and produce a total of 320 offspring, how many of these offspring are expected to exhibit a black body with normal wings?