Unit 3 Population

Fill-in-the-blank flashcards covering key concepts from Population notes.

A population is a group of individuals of a particular species occupying a __ area at a specific time and functioning as part of a biotic community.

specific

In a __ population, the growth of such individuals is determinate and predictable.

unitary

A __ population shows a branching pattern with several modules produced from a unit module.

modular

Biologists distinguish Genet from Ramet: an organism arising from a zygote is a __, while ramets arise asexually.

Genet

Population ecology is the study of populations in relation to the __.

environment

Key Population characteristics include Population size and density, __, and Life tables.

Dispersion

Crude density is density per unit total space; Specific (ecological) density is density per unit of habitat space, also called __ density.

ecological

Dispersion patterns can be __, __, or __.

clumped; uniform; random

Clumped dispersion may result from social __ or patches of environment that are more favorable for the population.

aggregations

Uniform dispersion is common in __ systems and occurs with territorial behavior.

managed

Random dispersion occurs when the position of one individual is unrelated to its neighbor, often described as __ dispersion.

random

Age structure refers to the proportions of individuals in each __ group.

age

Natality is the number of offspring produced per female per unit __.

time

Absolute Natality Rate (B) is defined as ΔNn/Δt; Specific Natality Rate (b) is ΔNn/(NΔt); these equations illustrate natality in terms of changes over __.

time interval

Theoretical maximum production of new individuals under ideal conditions is called __ (also referred to as fecundity rate).

Absolute Natality

Population increase under actual environmental conditions is described by Ecological/ Realised Natality, also called the __ (Fertility Rate).

Realised Natality

Mortality refers to the death rate in a population; the theoretical minimum under ideal non-limiting conditions is called __ mortality.

Minimum

The actual loss of individuals under a given environmental condition is called __ mortality.

Ecological

A life table is an age-specific summary of the survival pattern of a population and is constructed by following a __ from birth to death.

cohort

In a life table, lx is the number alive at the start of the age interval; dx is the number dying during the interval; qx is the __ rate; ex is the life expectancy at the end of the interval.

mortality

Survivorship curves can be classified into three general types: Type I, Type II, and Type III; Type II is characterized by a constant __ rate throughout life.

mortality

The Type II survivorship curve is typically observed in __ and , with a fairly steady death rate throughout life.

birds; rodents

A juvenile phase with high mortality and a post-juvenile phase where mortality first decreases and then increases describes a typical mortality curve, which is roughly __ shaped.

J-shaped

Most organisms disperse at some life stage; dispersal movements include one-way emigration and a return trip called __.

migration

The monarch butterfly exhibits unusual migration: fall migrants don’t return north, but their __ migrate.

offspring

Sex ratio is the proportion of males to females; many populations tend toward a __ sex ratio.

1:1

In elk populations, fetuses often show a sex ratio skewed toward __ at birth.

males

A fecundity table relates age-specific reproduction to age structure and survivorship; the data count only the females producing females, with mx representing the average number of offspring per female of age __.

x

lxmx value gives the mean number of females born in each age group; R0 is the mean number of female offspring produced by a female during her .

lifetime

Generation Time, T, is the average age at which a female gives birth to an offspring.

generation time

The rate of increase, r, for a population in a given environment can be calculated from life-table data including __ and mx.

lx and mx