In a forest ecosystem, a specific plant species, Acacia, is introduced to an area where it has no natural predators or competitors. Initially, the population of Acacia grows exponentially due to the abundant resources and ideal environmental conditions. However, as the population increases, factors such as competition for resources, predation, and disease begin to affect the growth rate. Over time, the population reaches a point where it stabilizes, and the growth rate levels off.
The type of population growth observed initially in the Acacia population is:
Answer: A) Exponential growth
As the population of Acacia stabilizes, the growth model it follows is known as:
Answer: B) Logistic growth
The carrying capacity of the environment refers to:
Answer: A) The maximum population size the environment can support indefinitely
The factors that regulate the growth of the Acacia population as it stabilizes are known as:
Answer: C) Density-dependent factors
The Sahara Desert is one of the hottest and driest places on Earth, with temperatures reaching up to 50°C during the day. Organisms living in the desert have evolved several adaptations to survive in this extreme environment. For example, cacti have thick, fleshy stems that store water, and their leaves are modified into spines to reduce water loss. Similarly, desert foxes have large ears that help dissipate heat. These adaptations help organisms conserve water and regulate their body temperature in the harsh desert conditions.
The adaptation of cacti in the desert to store water is an example of:
Answer: C) Structural adaptation
Desert foxes have large ears to:
Answer: B) Help dissipate excess body heat
The ability of desert organisms to survive extreme temperatures and low water availability is primarily due to:
Answer: B) Adaptations that help conserve water
In desert ecosystems, the primary factor limiting the survival of most organisms is:
Answer: B) Water availability
In a forest ecosystem, deer are the primary prey for wolves. The population of wolves is dependent on the number of deer available for hunting. When the deer population increases, the wolf population also increases due to more food availability. However, as the wolf population grows, the deer population starts to decrease due to increased predation. This decrease in the deer population results in a decline in the wolf population due to reduced food supply. This cycle of population increase and decrease between predators and prey is known as the Lotka-Volterra model.
In the given case, the deer population is primarily regulated by:
Answer: B) Predation by wolves
The Lotka-Volterra model describes the interaction between:
Answer: B) A predator and its prey
The decrease in the wolf population after the deer population declines is an example of:
Answer: A) Density-dependent regulation
In the predator-prey cycle described, the deer population is most likely to increase when:
Answer: A) The wolf population decreases
In a tropical rainforest, organisms are often distributed in clumped patterns due to the presence of abundant resources like food, water, and shelter. Elephants, for instance, form herds that help them protect each other from predators and increase their chances of survival. The population density of elephants in the rainforest is influenced by the availability of food, water, and mating opportunities. Areas with more resources tend to have higher population densities.
The clumped distribution of elephants in the rainforest is most likely due to:
Answer: B) Social behavior and protection from predators
The term population density refers to:
Answer: B) The number of individuals of a species per unit area or volume
The population density of elephants in the rainforest would likely be highest in areas where:
Answer: A) Food and water are abundant
A uniform distribution of organisms within an ecosystem is typically the result of:
Answer: A) High competition for resources
In a freshwater ecosystem, fish species such as salmon occupy a specific habitat where they have access to abundant food and suitable breeding grounds. Each species has a unique niche that defines its role in the ecosystem, including its interactions with other species, feeding habits, and reproductive strategies. The introduction of non-native species that compete for similar resources can lead to a shift in the population dynamics of native species, as they must either adapt or face population decline.
The niche of an organism refers to:
Answer: B) Its role and interactions within an ecosystem
The introduction of a non-native species that competes for similar resources with native species would most likely:
Answer: C) Lead to a decline in the population of native species
The habitat of an organism refers to:
Answer: B) The specific environment it occupies
A species' niche is different from its habitat because:
Answer: A) The niche includes both physical space and ecological role, while habitat refers only to physical space