bio 171- quiz 13

Assuming that no density dependent factors are acting on a population, which of the following is a valid way to calculate the per capita population growth rate (rmax) in a population?

b - d + i - e

A population of prairie dogs shows logistic growth. As the population approaches carrying capacity (K), the number of individuals added to the population per unit of time ________.

decreases

True or false: All plants have constitutive defenses against herbivores.

false

A population of starlings reproduces once per year. The annual geometric growth rate of the population is 4. The population had 80 individuals in 1982. How many individuals will there be in 1984? Assume that starlings die after reproducing, and that individuals mature and can reproduce within a year.

1280

Which of the following statements about arthropods is FALSE? Arthropods are eukaryotes. Arthropods have jointed legs. Arthropods grow when they molt. Arthropods have exoskeletons made of chitin. Arthropods are a kind of insect.

Arthropods are a kind of insect.

Which of the following is NOT an animal phylum? (Refer to table 44.1, page 955) Cnidaria Arthropoda Brachiopoda Porifera Echinodermata Insecta Mollusca Chordata

Insecta

A population of birds that had gone extinct on a tiny island was reintroduced to that island. The generation time of these birds is 1 year. 20 birds were re-introduced to the island in 2010. In the first year after the population was re-introduced, r was 0.1. How many birds will be on the island in 2200?

It is not possible to predict, as r is unlikely to remain constant over such a long time interval.

We use the population model below to describe the rate of population growth (how quickly or slowly a population is growing or shrinking): dN/dt = rmax · Nt In this model, Nt refers to:____________.

Number of individuals in the population at time = t

____________ can have similar effects on population sizes as predators; that is, they can regulate populations below carrying capacity.

Parasites

We use this population model to predict the population size at a given time, assuming you know the population's size at some initial time point: Nt = λt·N0 In this model, λt is the:

Ratio of the population size at time t and the initial population size

Ticks feed on the blood of mice and other mammals. In 2012, ecologists studied the interaction between ticks and the white-footed mice in an oak forest. They found that when tick density is high, fitness of white-footed mice declined; they would characterize the interaction between ticks and mice as ______________. In 2013, tick density was low and the researchers found no effect on mouse fitness; they would characterize the species interaction between ticks and mice as ______________.

parasitism; commensalism

If intraspecific competition (a density dependent factor) is affecting population growth, which of the following should we use to find the rate of change in population size? rmax· Nt lambda (?), since we know that it will be less than 1 during density dependent growth λt·N0 rmax, since we know that r will be constant under such conditions rmax Nt [(K- Nt)/K]

rmax Nt [(K- Nt)/K]

We use this population model to predict the population size at a given time, assuming you know the population's size at the time just before: Nt+1= λ·Nt In this model, lambda (λ) refers to:_________.

Geometric population growth rate

The per-capita growth rate of a population is 0.1 per day. The per capita birth rate is 0.2 per day. The per capita death rate is 0.2 per day. What can you conclude from this information?

That the population is growing. That immigration exceeds emigration in this population. That this is an open population (immigration and emigration occur).