Chapter 12 Life Histories Flashcards
A scientist studying the life history of a particular species would ask which of the following questions?
What are the trade-offs for producing either many small offspring or several large offspring?
What are the factors that influence age at first reproduction?
One of the biggest trade-offs in reproduction for many organisms is ______.
the number of offspring versus the size of the offspring
If an organism produces many offspring, ______.
the offspring will be small because of limited energy resources
Clutch size in fish can range from ______. (book)
one to 600 million
The number of eggs or seeds produced by an organism is known as ______
fecundity
A scientist investigating the environmental factors that determine the age at first reproduction would be studying ______.
life history
Darters are an ideal organism for studying gene flow among populations because there are ______.
many species that live in similar habitats
Why can’t an organism produce many large offspring?
Energy and resources are limited.
The trade-off between offspring size and number in darters is the fish that produce ______.
larger eggs produce fewer eggs
If an organism produces few larger offspring, the ______.
parents will typically invest more time and energy into each individual
Which group of animals shows the most variation in life history traits?
fish
A polymorphic locus ______
has two or more alleles
An organism with high fecundity would ______.
produce a large number of eggs or seeds
High levels of gene flow would most likely lead to ______.
genetically similar populations
What are the characteristics of darters that make them an ideal organism for studying gene flow?
Darters vary greatly in their life history characteristics.
Darters live in similar habitats and also have similar anatomy.
Darters are a taxonomically diverse group.
The findings of Turner and Trexler found that larger darters produce ______. (book)
a larger number of eggs
Darters that produced larger eggs had ______.
lower rates of gene flow between populations
When different alleles are found in a population that synthesizes different allozymes, this is known as a ______.
polymorphic locus
The smallest seeds known are produced by ______. (book)
orchids
Restricted gene flow between populations would most likely lead to ______.
genetic differences between populations
Plants that produce many seeds have seeds that are ______.
smaller
Populations of darters with higher rates of gene flow typically ______.
produce many smaller eggs
Determining mechanisms that select for seed size in plants is difficult due to ______.
the varied growth forms of plants
The largest seeds known are produced by ______.
coconut palms
Woody plants and vines produce ______.
larger seeds than graminoids
The sand spur, often found at sandy beaches, has barbs that latch onto fur or skin. This plant’s mode of dispersal would best be described as ______.
adhesion-adapted
Comparing epiphytes to trees to determine the mechanisms driving the evolution of seed size is difficult because of ______.
the various growth forms of plants
Typically graminoids produce ______.
the smallest seeds
After hiking in the woods, you discover a seed with a barb that latched onto your pants. This plant would best be classified as ______.
adhesion-adapted
To attract birds and other mammals, some seeds have a fleshy covering known as a(n) ______.
aril
What is an advantage of producing larger seeds?
The seedlings may have higher survivorship in times of environmental stress.
The process during which a seed begins to produce a small seedling is known as ______.
germination
Jacobsson and Eriksson created control plots by ______. (book)
not planting seeds in half of the plots
Seeds that are cached by birds or mammals are classified by Westoby, Leishman, and Lord as ______.
scatterhoarded
On average, plants that produce larger seeds ______.
have higher rates of recruitment
What is the advantage of producing smaller seeds?
A plant can produce greater numbers of seeds.
The process during which seeds begin to grow is known as ______
germination
Based on Seiwa’s and Kikuzawa’s studies, taller seedlings are produced from ______. (book)
larger seeds that have greater energy reserves
Jacobsson and Eriksson created control plots to determine ______.
how many of the plants would have germinated without being planted
Larger seed size may be important in environments ______.
where competition with plants already present is high
When adult survival is higher, individuals will ______.
delay reproduction and allocate less energy into reproduction
Seiwa’s and Kikuzawa’s studies on seed size demonstrated that ______. (book)
larger seeds produce larger seedlings
Shine and Charnov point out that a juvenile will allocate resources to growth ______.
and maintenance only
Jacobsson and Eriksson created control plots by ______.
not planting seeds in half of the plots
In species where adults have lower survival rates, individuals will ______.
allocate more energy into reproduction and begin to reproduce earlier
Based on Shine and Charnov’s studies, the benefits of delaying reproduction include ______.
higher reproductive rates
higher growth rates as juveniles
