QCAA Biology Biodiversity and populations

While members of a species share a gene pool, individuals possess different combinations of alleles (genetic variation), and sharing alleles is not the primary definition of the biological species concept.

This definition aligns more closely with the phylogenetic species concept, which focuses on evolutionary history and common ancestry rather than reproductive isolation.

Defining a species by its specific ecological role or environment is known as the ecological species concept, not the biological species concept.

This answer results from incorrectly swapping the values for the total captured in the second sample ($n$) and the marked recaptures ($m$) in the formula ($N = \frac{36 \times 18}{24} = 27$).

This incorrect value likely results from simply adding the number of initially marked frogs to the number of marked frogs found in the second sample ($36 + 18 = 54$).

This incorrect value results from adding the number of initially marked frogs to the total number of frogs captured in the second sample ($36 + 24 = 60$) instead of using the multiplication and division required by the formula.

Community I has a species richness of 5 (species E is absent), which is lower than communities III and IV. Additionally, it has low evenness because the population is dominated by species F and A.

Community II has a species richness of 5 (species C is absent), which is lower than the maximum richness observed in other communities. It also shows low evenness due to the dominance of species F.

Although Community III has the highest species richness (6 species), it has low evenness. The abundance is skewed heavily toward species F (51) and C (28), while other species have very low counts.

A niche refers to the role or function an organism plays within its ecosystem, such as its feeding habits and interactions, rather than just the physical location.

A community is a group of interacting populations of different species living in the same area, not the location itself.

While the environment encompasses all external factors affecting an organism, "habitat" is the specific biological term for the place where it lives.

The investigation only has one dependent variable, which is the percentage increase in mass of the lettuce.

Using only one type of plant is necessary to control variables and ensure a fair test, so this does not invalidate the experiment.

Keeping the light wavelength constant at 660 nm is a controlled variable, which actually supports the validity of the experiment rather than undermining it.

This value is incorrect. It results from miscalculating the net change or using the wrong denominator in the growth rate formula.

This calculation incorrectly considers only the population inputs (Births + Immigration) divided by the initial population ($\frac{8390}{15\,200} \approx 55\%$), failing to subtract deaths and emigration.

This option is incorrect and likely represents the complement of the correct answer ($100\% - 27\% = 73\%$), rather than the actual growth rate.

The concentration of carbon dioxide is a measurable, numerical value, making it quantitative data rather than qualitative.

The number of chlorophyll molecules is a countable, numerical value, which represents quantitative data.

The mass of minerals is a measurable, numerical value, making it quantitative data.

Marked differences in physical appearance (phenotype) can exist between populations of the same species due to genetic variation and local adaptation, much like different breeds of dogs.

Genetic variation, such as differences in the DNA sequence of a specific gene, naturally occurs between individuals and populations within the exact same species.

A survival advantage indicates a difference in fitness or adaptation to a specific environment, but it does not determine whether two groups are reproductively isolated distinct species.

Order is a more specific rank than class; organisms in the same class can belong to different orders (e.g., humans and cats are both class Mammalia but belong to orders Primates and Carnivora, respectively).

Genus is a much lower, more specific rank than class; sharing a broad category like class does not imply sharing a specific category like genus.

Family is a lower taxonomic rank than class; organisms within the same class are usually divided into many different families.