Interdependent Relationships in Ecosystems Flashcards
Identify biotic interactions like competition and mutualism, and evaluate factors influencing carrying capacity. (173 cards)
1
Q
Define:
Endosymbiosis
A
When a smaller organism lives within the cells, tissues, or some other structure inside a host organism’s body.
2
Q
What are the three types of symbiotic relationships?
A
- Mutualism: positive for both organisms.
- Commensalism: positive for one, neutral for the other.
- Parasitism: positive for one, negative for the other.
3
Q
Define:
Ectosymbiosis
A
When an organism lives on the surface of another organism.
4
Q
Define:
Mutualism
A
A symbiotic relationship where both organisms benefit.
Example: Bees get nectar from flowers and carry pollen to help pollinate plants.
5
Q
Define:
Parasitism
A
A symbiotic relationship where one organism benefits and the other is harmed.
Example: Tapeworms live in larger organisms, taking nutrients from their intestines.
6
Q
Define:
Symbiosis
A
Any kind of relationship or interaction between two different organisms.
7
Q
Define:
Commensalism
A
When one organism benefits and the other is unaffected.
Example: Barnacles attach to whales and filter food from the water, while the whale is unaffected.
8
Q
What is the difference between a predator and prey?
A
- Predator captures and eats another organism.
- Prey is the organism being captured and eaten.
9
Q
What is the process of hunting to capture and eat organisms known as?
A
Predation
10
Q
What are the two common types of predators?
A
- Carnivores: meat-eating organisms.
- Herbivores: plant-eating organisms.
11
Q
What is herbivory?
A
Whenever the prey organism in predation is a plant.
12
Q
What are some examples of predator adaptations?
A
- camouflage
- offensive techniques
These adaptations help the predator be more effective in hunting and catching prey.
13
Q
What is coevolution in predator-prey interactions?
A
When the fitness of two different species is tightly linked, and these two species evolve in response to evolutionary changes in each other.
14
Q
What is one example of prey adaptation?
A
The use of communication techniques to warn one another of predators.
Prey adaptations help the prey animal evade capture from a predator.
15
Q
What is camouflage in predator-prey interactions?
A
The process of using body shape and coloration to blend in with the environment.
16
Q
What is mimicry in predator-prey interactions?
A
Whenever one species has evolved to resemble another species that is toxic or dangerous to predators.
17
Q
What is warning coloration in predator-prey interactions?
A
- Specialized body coloration used to warn members of their group of dangerous predators.
- Specialized coloration used by prey organisms to deter predators.
18
Q
What is Batesian mimicry?
A
Occurs when an organism that is harmless mimics the warning coloration of a species that is harmful.
19
Q
What is Mullerian mimicry?
A
Occurs when two different species share the same warning coloration.
20
Q
What is interspecific competition?
A
The battle between two species for the same resources in an ecosystem.
Example: The Shenandoah salamander competing with the eastern red-backed salamander for habitat, leading to the Shenandoah salamander being designated as endangered.
21
Q
What are the three basic types of competition ecology?
A
- Interference competition
- Exploitation competition
- Apparent competition
22
Q
Define:
Exploitation competition
A
An indirect interaction between species over a limited resource where one organism’s use of resources depletes the total amount available to the other organism.
23
Q
Define:
Interference competition
A
Involves direct interaction between species over a limited resource through violence or aggressive behavior.
24
Q
What is niche differentiation?
A
The process by which competing species exploit their environment differently in order to coexist.
25
What is the **competitive exclusion principle**?
Two species **cannot persist in the same ecological habitat** for an extended period without being pushed out due to competition for limited resources.
## Footnote
Also known as Gause's principle or Grinell's axiom.
26
What are the consequences of **competitive exclusion**?
The **weak** competitor may be **excluded or extinct** from the habitat.
27
# Define:
Realized niche
It's where the species **actually live** including all limiting factors and competition.
28
What are **ecomorphs**?
Populations of distantly related animals that have recently acquired morphological differences to **adapt to certain environments**.
29
What is the **Lotka-Volterra competition model**?
A mathematical model that formalizes the impacts of interspecific competition on **populations**.
30
What is **intraspecific competition**?
Competition between individuals from the **same species**.
31
How does interspecific competition impact **species' survival**?
**It may lead to extinction** as less well-adapted species receive fewer resources, reducing their chances of survival.
32
# Define:
Fundamental niche
A theoretical niche that reflects all of the **ideal environments with no limiting factors** or competition in which a species may survive.
33
What are **keystone species**?
Organisms that other species in the ecosystem depend upon and whose disappearance would **devastate their biological communities**.
## Footnote
Prairie dog - They dig tunnels that form prairie dog towns, providing homes for various animals and improving soil health for plant growth and insect habitat.
34
What are some **examples** of common keystone species?
* Sea Otters
* Coral
* Grizzly Bears
* Honey Bees
35
# Define:
Ecosystem
All organisms **living in a certain area** and the **environment** surrounding that area.
36
If you were creating an assignment for your students to study keystone species, what details would you most likely have them research?
* Why is the organism they chose considered a keystone species?
* What is its role in the ecosystem?
* What is the importance to the ecosystem?
* What are current threats to the species?
37
What are some sources recommended for students to review before starting the assignment?
* World Wildlife Foundation (WWF)
* National Geographic
* Sources written by scientists, universities, or news outlets
38
# Define:
Apparent competition
When two individuals who do not compete for resources affect each other indirectly by being **prey to the same predator**.
39
# Define:
Dispersal
The **spread of organisms to new areas** through immigration and colonization.
40
What is the **difference** between dispersal and dispersion?
* **Dispersal** refers to the actual process by which organisms spread.
* **Dispersion** describes the pattern in which organisms are already spread within a population.
41
How do **immobile** aquatic species like barnacles and corals solve the dispersal problem?
They release sperm and eggs into the water in a coordinated fashion with the rest of their population, resulting in millions of zygotes that develop into mobile or free-floating larval forms.
42
How do terrestrial **plants** disperse their seeds?
Some release seeds or spores to be carried long distances by wind and air currents, while others rely on animals to spread their seeds.
43
How does immigration **relate** to colonization?
If **immigration** occurs in an area **not already occupied** by that species, it can result in **colonization**, where the organism **starts a population in a new habitat**.
44
Explain the concept of **habitat fragmentation** and its impact on dispersal and populations.
It is the process of **breaking up large habitats into smaller, isolated pieces**. It affects dispersal, immigration, colonization, and populations by limiting movement, gene flow, and access to resources.
45
What factors does the **Island biogeography theory** focus on to estimate species diversity?
The **size of the habitat** and the **distance** from a source of species.
46
How does the **Island biogeography theory** predict species diversity on islands?
The theory predicts that **larger islands and islands closer to the mainland will have greater species diversity** than smaller islands or those further away from the mainland.
47
What is the **equilibrium point** in the Island Biogeography theory and what does it represent?
It represents the **balance between colonization and extinction** and predicts the number of species that can be found on the island.
48
What is the **significance** of the Island biogeography theory in ecology?
It serves as a **basis for predicting species diversity on islands** and has inspired other ecologists to develop more complex theories related to species diversity, colonization, and population survival.
49
How might **dispersal** occur for immobile species?
It can occur through **passive means** such as wind or water.
50
# Define:
Colonization
The establishment of a population in a **new area**.
51
Summarize **Island biogeography** and its significance.
* It is the study of the **distribution and abundance of species on islands**.
* It provides **insights** into species diversity, extinction rates, and colonization patterns.
52
What is an **r-selected species** and why is it called that?
It exhibits **high reproductive rates followed by high mortality rates** that lead to populations with highly fluctuating numbers.
## Footnote
R-selected species have very low parent involvement and typically a short lifespan.
Examples: Rabbits, jellyfish, bacteria
53
What is a **K- selected** species?
They **produce fewer offspring** but spend a lot of time and resources ensuring that those few offspring make it to adulthood.
## Footnote
Low juvenile mortality rates, typically long lifespan.
Examples: Humans, elephants, whales.
54
What is the main **difference** between r-selected and K-selected species?
* **r-selected species** have populations that fluctuate wildly as a result of high birth rates followed by high mortality rates.
* **K-selected species** have more stable populations with low birth rates and low mortality rates.
55
What does the '**K**' in K-selected species stand for?
carrying capacity
## Footnote
K-selected species tend to stay close to carrying capacity.
56
What is **exponential growth** in Biology?
Growth with a **constant per capita** growth rate.
57
What does **exponential growth** produce in a population?
Values that 'snowball,' so the **total rate of change keeps increasing** without bounds.
58
What pattern does **logistic growth** follow?
A sigmoid (S-shaped) curve.
## Footnote
Growth starts slowly, accelerates, then slows down again to plateau.
59
Give an **example** of logistic growth in biology.
The percentage of a population that has been **infected with a very contagious pathogen**.
60
When can **exponential growth** occur in a population?
When the population size is small compared to the carrying capacity or when the organism has no natural predators in the environment.
61
What is the exponential growth **equation**?
𝑦=𝑎𝑏𝑥
## Footnote
y = the quantity being tracked
a = the starting value
b = the common ratio (the value that the y-values keep getting multiplied by)
x = time
62
What is the **key difference** between exponential growth and logistic growth?
* **Exponential growth** is unaffected by the carrying capacity and produces a growth curve that keeps getting steeper.
* **Logistic growth** slows down after initial exponential growth.
63
What is **carrying capacity**?
An ecosystem's **maximum number of organisms** of a species that can survive in that particular environment.
64
What is the **formula** to calculate **carrying capacity**?
𝐾=𝑟∗𝑁∗(1−𝑁)÷𝐶𝑃
## Footnote
K = the carrying capacity
r = rate of population growth
N = the current population size
CP = change in population size.
65
What is the **range in population** carrying capacity?
The physical boundaries that **encompass a particular population**, influencing the availability of resources.
66
List the **three types** of dispersion patterns.
* uniform
* clumped
* random
67
# Define:
Random dispersion
When organisms **exist without a specific observable pattern**, often due to ample resources and little competition.
68
How does **migration** affect carrying capacity?
Migration **increases the resources available to the population** that is moving, thus increasing their carrying capacity.
69
# Define:
Uniform dispersion
Organisms equally distanced from each other in an **orderly pattern**, typically the result of intraspecific competition.
70
# Define:
Clumped dispersion
**Organisms crowding** near one another, usually the result of crowding around pockets of available resources.
71
What is **migration**?
The periodic **movement of a population**, often driven by the need **to gain access to food**.
72
What is **fertility**?
The **number of an organism bears** during their reproductive years.
73
What is the **crude birth rate**?
The **number of live births** in a given year for every 1,000 people in a population.
74
What is **fecundity**?
The biological capability and **capacity of bearing children**.
75
What is **replacement level**?
The **level of fertility required to replace themselves** and their partner in a population.
76
What is the **mortality rate**?
The measure of the **number of deaths** in a population.
77
What is the **difference** between immigrants and emigrants?
* **Immigrants** are people entering a country.
* **Emigrants** are people leaving a country.
78
What is the formula for **population change**?
(births + immigration) - (death + emigration) = population change
79
What does **net migration** represent?
It is the **mathematical difference** between those migrating **into** a country and those migrating **out** of a country.
80
How can **population change** be determined?
Through the use of fertility, mortality, and migration rates.
81
# Define:
immigration
The movement of individuals into a **population** or area.
82
How are **age tables** utilized in biology?
Age tables can be analyzed to **create survivorship curves** as well as population growth models.
83
What **information** is able to be obtained from a survivorship curve?
* types of survivorship
* life expectancy
* reproductive timing
84
What are the **three types** of **survivorship**?
* Type **1** - high survivorship in early life
* Type **2** - constant survivorship across all ages
* Type **3** - high mortality in early life
85
**Humans** exhibit what type of survivorship?
Type **1** - High survivorship in early life
86
What type of survivorship is exhibited in **birds**?
Type **2** - Constant survivorship across all ages
87
What type of survivorship is exhibited in **fish** and **insects**?
Type **3** - High mortality in early life
88
What are **limiting factors** in ecology?
Anything that **keeps a population from continuing to grow** within an ecosystem.
## Footnote
* Physical factors
* Biological factors
* Density-independent factors
* Density-dependent factors
89
How do limiting factors **most affect** population size?
Population numbers in an ecosystem **rise and fall** due to the **fluctuation** of limiting factors.
## Footnote
When there are few limiting factors, the population grows.
When there are many limiting factors, the population declines.
90
What are **physical factors** as limiting factors?
* temperature
* water
* oxygen
* light
91
What are **biological factors** as limiting factors?
* predation
* competition
* parasitism
92
What are **density-independent** factors as limiting factors?
* natural disasters
* climate change
* pollution
## Footnote
These limiting factors are not influenced by how many organisms inhabit an area.
93
What are **density-dependent** factors as limiting factors?
* disease
* resource availability
## Footnote
Density dependent factors are influenced by how many organisms inhabit an area.
94
How are limiting factors **related** to carrying capacity in the context of ecosystems and population dynamics?
They influence the carrying capacity of a population.
## Footnote
Limiting factors such as food, water, shelter, and space restrict how many individuals an environment can support.
The more resources that are available in the ecosystem, the more organisms it can sustain. Conversely, when resources are scarce, the population size decreases to remain within the ecosystem’s carrying capacity.
95
How can **food and water** limit population growth?
* **Sufficient** resources lead to **population growth**.
* **Scarcity** leads to population **decline**.
96
What are the **two types** of limiting factors to population growth?
* Biotic factors
* Abiotic factors
97
What are examples of **biotic** limiting factors?
Plants and animals as food sources.
98
What are examples of **abiotic** limiting factors?
Physical factors such as temperature and water resources.
99
What is the **carrying capacity** of a population?
The **maximum number** of an organism a population can hold.
100
What is a **habitat**?
The **natural home or place within an ecosystem** that provides the kind of food, water, shelter, and living space an organism needs to survive.
101
What is a **niche**?
The **special role** an organism plays within its ecosystem.
102
How do **niches** contribute to minimal competition within an ecosystem?
Different species of organisms **do not typically ever occupy the same niche** within their ecosystem, reducing competition for the same resources.
103
What is a **population** in biology?
A group of organisms of the **same species living within an area**.
104
Explain the **relationship** between ecosystems, habitats, and niches.
* **Ecosystems** are the interaction between biotic and abiotic factors.
* **Habitats** are suitable places for organisms.
* **Niches** are the specific roles organisms play.
105
What determines the **niche** of an animal within its ecosystem?
Feeding habits and other adaptations.
106
Why are **abiotic factors** important to an ecosystem?
Abiotic factors **contribute to the habitat** of an organism. The availability of abiotic factors contributes to the **availability of many resources** organisms rely on to survive.
107
Does the picture depict a **biotic** factor of an **abiotic** factor?
abiotic factor
## Footnote
Sunlight and water are not living organisms.
108
Does the picture depict a **biotic** factor of an **abiotic** factor?
biotic factor
## Footnote
Plants are living organisms.
109
Does the picture depict a **biotic** factor or an **abiotic** factor?
biotic factor
## Footnote
Dolphins are living organisms.
110
Does the picture depict a **biotic** factor of an **abiotic** factor?
abiotic factor
## Footnote
Rocks are not living organisms.
111
How do abiotic factors like temperature and sunlight **influence the distribution** of **biotic factors** in an ecosystem?
They determine the **types and numbers** of organisms that can **survive** in a given area.
## Footnote
Abiotic factors like temperature and sunlight directly affect which species can live and reproduce in an ecosystem.
Regions with suitable temperatures and sufficient sunlight support more diverse and abundant life than areas with harsh or limited conditions.
112
How are **current shifts** in abiotic factors influencing Earth's ecosystems?
Shifts in abiotic factors such as **increased temperature due to global warming** are causing draught, extreme weather, and increased water temperature. If the organisms living in that ecosystem are **not adapted** to these changes they will **not be able to live successfully**.
113
How do **human activities** impact the balance between biotic and abiotic factors in ecosystems?
Human activities contribute to a **degradation** of abiotic factors in ecosystems due to infrastructure development and pollution.
114
How do abiotic factors influence the **reproductive strategies** of biotic factors in different ecosystems?
Abiotic factors **determine the availability of resources** in an ecosystem. Organisms will **adapt** in order to reproduce when those resources are the most widely available in order to provide their offspring with the **best chance at survival**.
115
What is an example of how biotic factors can **modify** abiotic factors in an ecosystem?
Beavers build dams in streams which may redirect water flow to areas of an ecosystem where water was not previously flowing.
116
What is **ecological succession**?
The process in which disturbed regions are **colonized** by organisms that are gradually **replaced by new species**.
117
What are the **stages** involved in ecological succession?
* Initial Conditions (Equilibrium)
* Disturbance
* Colonization
* Competition
* Succession
* Climax
118
What is the role of the **disturbance** in ecological succession?
The event that **severely damages or destroys the existing ecosystem**, leading to little or no life remaining in the area.
119
What is **colonization** in ecological succession?
The **return of tiny organisms** to the damaged ecosystem after a disturbance.
120
What is **competition** in ecological succession?
The process where colonizing organisms **change environmental conditions**, leading to resource competition as biodiversity increases.
121
What is the **climax** stage in ecological succession?
The final stage where a **climax community is formed with minimal resource competition** and no further replacement of dominant plant species.
## Footnote
The community has returned to equilibrium.
122
What is **primary succession**?
Succession that occurs when there is **little to no soil left after a significant geological event**, with colonization by microscopic organisms and pioneer species.
## Footnote
Example: The recovery of the Mount Saint Helens region after the 1980 eruption.
123
What is **secondary succession**?
Succession that occurs after an **existing landscape has been altered** by human activities or natural events, allowing plant species to establish themselves more quickly.
## Footnote
There is still soil left in place.
Example: The recovery of chaparral ecosystems after a wildfire.
124
What are **fire followers**?
**Plants that grow shortly after a wildfire** due to adaptations like roots that spread deep into the ground and seed pods opened by fire.
## Footnote
Examples:
* Fire Poppies
* Whispering Bells
* Golden Eardrops
125
What are **pioneer species**?
The **first wave of species that repopulate** the environment after a disturbance, usually hardy primary producers.
126
How does **biodiversity** affect ecological succession?
As biodiversity grows, resource competition increases, leading to the formation of a climax community.
127
What are **examples of disturbances** that could lead to ecological succession?
* volcanic eruptions
* fires
* logging
* hurricanes
128
How do **pioneer species** help to contribute to the creation of soil?
Pioneer species are able to **grow on barren rocks**, and contribute to the weathering process which in turn creates soil.
129
What are **examples** of pioneer species?
* lichens
* algae
* moss
130
How do we know a **climax community** has been reached after succession?
The community has reached a steady state in which organisms have found their niche.
131
What **type of succession** is being described in the following scenario?
A new island emerges from the ocean due to volcanic activity. The island has no soil or vegetation. Over time, life begins to colonize the barren landscape.
Primary succession
132
What **type of succession** is being described in the following scenario?
A wildfire has gone through a forest and disturbed the vegetation that was found there. Over time grasses, shrubs and other plants begin to grow back.
Secondary succession
133
Why is it important for climax communities to have a **large amount of biodiversity**?
An increase in biodiversity leads to an **increase in genetic variation** that can bring about **beneficial traits**.
134
What is the **importance of initial conditions** in ecological succession?
Initial conditions help to determine the species that will be able to **pioneer the ecosystem** and what will be able to live there **successfully** in the future.
135
Why is **ecological succession** important in ecosystems?
Succession causes ecosystems to evolve meaning the organisms that are best **suited for the environment** will thrive **contributing to the biodiversity** of the ecosystem.
## Footnote
Higher biodiversity mean the ecosystem is able to recover more easily from disturbances.
136
What factors will influence the **rate of succession**?
* type of disturbance
* soil quality
* availability of biotic factors
* interactions among species in the ecosystem
137
How do **human activities** impact ecological succession?
Human activities such as construction and pollution **disrupt resource availability** in ecosystems eventually leading to habitat loss, and reduced biodiversity.
138
What are the **challenges** of studying ecological succession?
Succession takes place over such a long period, involves very complex organism interactions, and is influenced by factors such as climate change making it is difficult to study.
139
How can understanding ecological succession aid conservationists in developing more **effective conservation strategies**?
Understanding succession helps conservationists identify how ecosystems are able to **recover after a disturbance** so that they are able to implement strategies that can help **conserve an ecosystem** that is struggling.
140
How does **biodiversity change** throughout the stages of ecological succession?
Biodiversity is very low when succession begins, but **continually increases** until a climax community with high biodiversity is reached.
141
What role do **animals** play in the process of ecological succession?
Animals **interact with their environments** in a way that is able to disperse seeds, change the soil composition and help to control the growth of vegetation in an area, ultimately leading to an **increase in biodiversity**.
142
What are some examples of **human-induced disturbances** that can lead to secondary succession?
* deforestation
* agriculture
* housing developments
* pollution
143
How do **invasive species** affect the process of ecological succession?
An invasive species can disrupt succession by **consuming valuable resources** and **disturbing established interactions** within ecosystems, which can eventually lead to reduced biodiversity due to a lack of available resources.
144
What is the **study of the evolutionary development** of animal behavior as a result of ecological pressure called?
behavioral ecology
## Footnote
Behavioral ecology examines how external factors influence species to evolve certain behavioral traits.
145
What term describes a series of **interacting social behaviors** that develop stable social relations?
Evolutionarily Stable Strategy
| (ESS)
## Footnote
ESS is crucial for understanding social behaviors in the context of behavioral ecology.
146
What is an **example** of a behavior evolved to benefit an individual, even at the expense of another?
Female mantis eating the male after reproducing.
## Footnote
This behavior increases the female’s chances of survival and reproduction. It shows how evolution can favor behaviors that benefit one organism, even if they harm another.
147
Why do lions exhibit **territorial** behavior?
To **protect** resources from other predators.
## Footnote
Territorial behavior is a response to ecological pressure due to limited resources in their environment.
148
What role does **mating** play in a species' survival?
Selection of reproductive partners and **production of offspring**.
## Footnote
Mating behaviors are instinctual and evolved to enhance the chances of survival for offspring.
149
What is often the responsibility of females in mating behaviors?
Selecting a mate
## Footnote
This behavior allows females to choose partners with traits that increase the chances of survival for their offspring.
150
What is a common **child-rearing practice** observed in humans and many primates?
social child raising
## Footnote
This practice enhances survival by allowing multiple individuals to contribute to raising offspring.
151
# Fill in the blank:
The defense of resources within a territory is known as \_\_\_\_\_\_\_.
territoriality
## Footnote
Territoriality is a behavioral trait evolved in response to ecological pressure.
152
What are the **four main types of social behavior** within groups?
* altruism
* selfishness
* cooperation
* spite
## Footnote
These behaviors define interactions within social groups.
153
# Define:
social group
A group of animals **living together to increase survival** and **reproductive** success.
## Footnote
This definition applies to both humans and other animals.
154
What are the **two main benefits of living** in social groups?
* improved hunting success
* improved protection from predators
## Footnote
Examples include dolphins hunting in groups and the difficulty predators face isolating prey.
155
What are the **two main costs of living** in groups?
* increase in competition
* increase in the spread of diseases
## Footnote
Competition arises for food and mates, while close living conditions facilitate disease transmission.
156
What is **altruism**?
A behavior that **benefits the recipient** at a cost to the performer.
## Footnote
Examples include actions by lifeguards or firefighters.
157
What is **kin selection**?
The process where an individual helps its **relatives** to **increase the survival of its traits**.
## Footnote
This often results in altruistic behaviors, like donating a kidney to a relative.
158
List the **three main costs** associated with **altruism**.
* energy cost
* opportunity cost
* risk cost
## Footnote
These costs must be considered before performing an altruistic act.
159
# Fill in the blank:
You are more likely to donate a kidney to someone who is closely \_\_\_\_\_\_ to you than to someone who is not.
related
## Footnote
This behavior illustrates kin selection.
160
What is the **fundamental driving force** behind animal behavior?
reproduction
## Footnote
Reproduction ensures the passing of genes to the next generation, which is crucial for species survival.
161
What are the **two main types of reproduction** in animals?
* asexual reproduction
* sexual reproduction
## Footnote
Asexual reproduction involves producing offspring without a partner, while sexual reproduction combines genes from two parents.
162
What is **asexual reproduction** and where is it commonly observed?
Asexual reproduction is when an organism **produces a copy of itself without a partner**.
## Footnote
Common in non-animal species like bacteria and some corals and flatworms.
163
What are the **advantages** of sexual reproduction?
* genetic diversity
* better adaptation to environmental changes
## Footnote
Sexual reproduction mixes genes from two parents, increasing the likelihood of survival for the species.
164
What are the two categories of **mating systems**?
* monogamy
* polygamy
## Footnote
Monogamy is one male with one female, while polygamy involves multiple mating partners.
165
What is **monogamy** and when is it typically observed?
Monogamy is when **one male mates with one female**.
## Footnote
Often seen in species where both parents are needed to care for the young.
166
What is **polygyny**?
A form of polygamy where **one male mates with multiple females**.
## Footnote
In this system, females typically care for the offspring alone.
167
What is **polyandry**?
A form of polygamy in which **one female mates with multiple males**.
## Footnote
This mating system is less common but observed in some birds, insects, and fish.
168
What are **pheromones**?
**Chemical signals** released by animals when **ready to mate**.
## Footnote
Pheromones can be powerful attractants for potential mates.
169
What is the significance of **courtship** behaviors in animal mating?
Courtship behaviors are key to **attracting a mate**.
## Footnote
These behaviors can include vocalizations, coloration, and displays of skill.
170
Who typically engages in courtship behaviors in most species?
Males
## Footnote
Males often display extravagant traits to attract females.
171
What **unusual behavior** might occur during mating in some species?
The female may eat the male after mating.
## Footnote
This behavior is observed in species like the black widow spider.
172
What is the **role** of genetic diversity in species survival?
It **increases adaptability** to environmental changes.
## Footnote
Genetic diversity helps some individuals survive illness or drought better than others.
173
What can influence whether a species is **monogamous** or **polygamous**?
The need for **parental care** for offspring.
## Footnote
If offspring require both parents for survival, monogamy is favored; otherwise, polygamy may be more advantageous.
