Fiveable
Fiveable

or

Log in

Find what you need to study


Light

Find what you need to study

8.1 Responses to the Environment

5 min readjanuary 13, 2023

Caroline Koffke

Caroline Koffke

Jed Quiaoit

Jed Quiaoit

Caroline Koffke

Caroline Koffke

Jed Quiaoit

Jed Quiaoit

The timing and coordination of biological mechanisms involved in growth, reproduction, and homeostasis depend on organisms responding to environmental cues. This is known as , which refers to the ability of organisms to detect and respond to changes in their environment. Organisms use a variety of behavioral and to sense and respond to changes in their environment, which allows them to optimize their chances of survival and reproduction (key to evolution). 🔑

Organism to Environment

One way organisms respond to changes in their environment is through behavioral mechanisms. Organisms can change their behavior in response to environmental cues, such as changes in temperature, light, or food availability. For example, migratory birds use the position of the sun and stars to navigate during their annual migration. Similarly, many insects use changes in day length to time the onset of reproduction. 🌞

Another way organisms respond to changes in their environment is through physiological mechanisms. These mechanisms involve changes in the activity of genes, enzymes, and hormones in response to environmental cues. For example, many plants change the shape of their leaves in response to changes in light intensity, which helps them to optimize their photosynthesis and avoid overheating. Similarly, many animals change the color of their skin or fur in response to changes in temperature, which helps them to regulate their body temperature.

Likewise, a number of environmental factors, such as changing temperature, weather patterns, an increase or decrease in food or water, or a decrease in a shelter can lead to changes within an organism. Many organisms are dependent on the seasons, hibernating or migrating in winter. These mechanisms and responses help them to survive and reproduce.

Examples

  • in plants is the ability of plants to sense changes in the length of daylight and to use this information to regulate growth and development.

For example, many plants use the length of daylight to time the onset of flowering. , such as poinsettias, will only flower when the days are shorter than a certain critical length, while , such as wheat, will only flower when the days are longer than a certain critical length. This ability allows plants to time their reproduction to coincide with optimal growing conditions.

  • is the ability of plants to sense changes in the direction of light and to use this information to orient their growth. For example, plants will grow towards the light in order to optimize their photosynthesis.

https://firebasestorage.googleapis.com/v0/b/fiveable-92889.appspot.com/o/images%2F-XECA5BpSTfJZ.jpg?alt=media&token=d9897ef8-e473-4f54-8dcf-55fa8b396a41

Source: Adobe

  • in animals refers to the ability of animals to move towards or away from a stimulus, such as light or a specific chemical.

For example, many insects are attracted to light, which they use to navigate towards food sources or mates.

  • in animals refers to the ability of animals to change the rate or direction of their movement in response to a stimulus, such as light or a specific chemical.

For example, when a cockroach detects an unpleasant odor, it will increase its rate of movement in order to escape from the source of the odor.

https://firebasestorage.googleapis.com/v0/b/fiveable-92889.appspot.com/o/images%2F-hNj3bQw2cR4z.jpg?alt=media&token=fed2d4b5-1555-4c71-b9a8-67441d99e58c

Source: Animal Behavior

  • Nocturnal and diurnal activity refer to the different patterns of activity that animals exhibit during the day and night. Nocturnal animals are active at night and sleep during the day, while diurnal animals are active during the day and sleep at night.

For example, lions are diurnal animals, while bats are nocturnal animals. These patterns of activity are usually determined by the availability of food and predators, as well as the temperature and light conditions.

  • is a physiological response to a perceived threat or danger. This response is characterized by the release of adrenaline and other hormones, which prepare the body for physical activity, such as fighting or running away. This response is triggered by the activation of the and it increases the heart rate, blood pressure and muscle tone.

https://firebasestorage.googleapis.com/v0/b/fiveable-92889.appspot.com/o/images%2F-TyZvCr6lfcs8.png?alt=media&token=6f7e7d24-c15b-4e35-b9cb-2277f0b20aa0

Source: Mount Marty

  • are the communication of danger by one organism to others of the same species.

For example, when a bird spots a predator, it will emit a specific alarm call that alerts other birds in the area to the danger. This allows them to take evasive action before the predator can attack. Some plants also have mechanisms to warn other plants of herbivory and will release chemical signals to warn nearby plants of an herbivore attack.

Organism to Organism: Communication is Key!

Organisms can also communicate with one another. Different species have their own highly evolved mechanisms of communication. This can involve the release of hormones, behavioral patterns, mating dances, warning calls, or any other number of responses. ❤️

https://firebasestorage.googleapis.com/v0/b/fiveable-92889.appspot.com/o/images%2Ftumblr_nx91y9YudG1sjwwzso1_540.gif?alt=media&token=6480bd83-eab3-4046-ba97-8890ebb4e256

Image courtesy of Giphy.

These forms of communications may be spurred by a physiological response from an organism, meaning something that occurs within themselves, such as hunger, or through an environmental change, such as the approaching of a predator. As a reminder, just like humans, many species communicate using verbal and nonverbal cues. This can involve audible warning signs and visible body language shifts. Some animal species have communication patterns that are far more complex than what we have.

Organisms often communicate changes that they sense in their environment in order to protect the members of their same species. For instance, prairie dogs are known to become very visible and give a loud warning call that can be heard by their own family members if a predator is approaching. While this may make them more susceptible to the predator, their genes will still be passed on by the family members that survive.

Connections to Evolution

Responses to information and communication of information are vital to and evolution. This is because the ability to sense and respond to environmental cues, as well as to exchange information with other individuals, can have a significant impact on an organism's survival and reproductive fitness. 💪

favors innate and that increase survival and reproductive fitness. For example, animals that are able to detect and avoid predators, or to find food and mates, are more likely to survive and reproduce than those that cannot. Similarly, plants that are able to sense and respond to changes in light intensity and direction, or to defend themselves against herbivores, are more likely to survive and reproduce than those that cannot.

also tends to increase the fitness of the individual and the survival of the population. For example, cooperative hunting, child-rearing, and care of the elderly in animals, and in plants and animals, such as pollination or seed dispersal, can increase the survival and reproduction of the individuals involved. This is because cooperation allows individuals to work together to achieve a common goal, such as obtaining food or protecting against predators, which can be more effective than working alone. 🐝

https://firebasestorage.googleapis.com/v0/b/fiveable-92889.appspot.com/o/images%2F-ktMJot0t3Yme.jpeg?alt=media&token=f084e51c-7c83-4abe-ae3d-c43690a87447

Source: ScienceDirect


-----

Key Terms to Review (20)

Behavioral Mechanisms

: Behavioral mechanisms refer to the actions or reactions of an organism in response to stimuli from its environment.

Communication in Organisms

: Communication in organisms refers to the transfer of information from one organism to another through signals or behaviors.

Cooperative Behavior

: Cooperative behavior refers to actions taken by organisms that benefit others in their group, often at a cost to themselves. This behavior is common in social species and contributes to the survival of the group as a whole.

Diurnal Activity

: Diurnal activity refers to the behavior of animals that are active during the day and rest or sleep at night.

Environmental Sensing

: Environmental sensing is the process by which organisms perceive and respond to certain changes in their environment.

Fight-or-Flight Response

: The fight-or-flight response is a physiological reaction that occurs in response to a perceived harmful event or threat to survival. It prepares an organism for fighting off harm or fleeing from danger.

Innate Behaviors

: Innate behaviors are those that occur naturally without any need for learning. They are instinctual and present at birth.

Kinesis

: Kinesis is a non-directional response where an organism's speed or activity level changes due to changes in their environment but not necessarily toward or away from any specific stimuli.

Learned Behaviors

: Learned behaviors are actions or behaviors that animals acquire through experience or observing others within their environment.

Long-Day Plants

: Long-day plants flower when nights are short; typically these types bloom in late spring or early summer when days are getting longer.

Mutualistic Relationships

: A mutualistic relationship is one where both organisms involved benefit from their interaction with each other.

Natural Selection

: Natural selection is a process in nature where organisms possessing certain genotypic characteristics that make them better adjusted to their environment tend to survive, reproduce, increase in number or frequency, and therefore, are able to pass on these favorable genetic traits to their offspring.

Nocturnal Activity

: Nocturnal activity refers to the behavior of animals that are active during the night and sleep during the day.

Photoperiodism

: Photoperiodism is the physiological reaction of organisms to the length of day or night. It triggers flowering, hibernation, migration and other behaviors.

Phototropism

: Phototropism is the growth or movement of a plant in response to light direction.

Physiological Mechanisms

: Physiological mechanisms refer to how living organisms' bodies function internally at both physical and chemical levels in response to their environments.

Predator Warnings

: Predator warnings are signals given by animals to alert others of potential threats from predators.

Short-Day Plants

: Short-day plants require a long period of darkness (shorter daylight) in each 24-hour cycle to induce flowering.

Sympathetic Nervous System

: The sympathetic nervous system is a part of the autonomic nervous system that prepares the body for action by triggering the fight-or-flight response.

Taxis

: Taxis is a directed movement towards or away from a stimulus such as light (phototaxis), heat (thermotaxis), or gravity (geotaxis).

8.1 Responses to the Environment

5 min readjanuary 13, 2023

Caroline Koffke

Caroline Koffke

Jed Quiaoit

Jed Quiaoit

Caroline Koffke

Caroline Koffke

Jed Quiaoit

Jed Quiaoit

The timing and coordination of biological mechanisms involved in growth, reproduction, and homeostasis depend on organisms responding to environmental cues. This is known as , which refers to the ability of organisms to detect and respond to changes in their environment. Organisms use a variety of behavioral and to sense and respond to changes in their environment, which allows them to optimize their chances of survival and reproduction (key to evolution). 🔑

Organism to Environment

One way organisms respond to changes in their environment is through behavioral mechanisms. Organisms can change their behavior in response to environmental cues, such as changes in temperature, light, or food availability. For example, migratory birds use the position of the sun and stars to navigate during their annual migration. Similarly, many insects use changes in day length to time the onset of reproduction. 🌞

Another way organisms respond to changes in their environment is through physiological mechanisms. These mechanisms involve changes in the activity of genes, enzymes, and hormones in response to environmental cues. For example, many plants change the shape of their leaves in response to changes in light intensity, which helps them to optimize their photosynthesis and avoid overheating. Similarly, many animals change the color of their skin or fur in response to changes in temperature, which helps them to regulate their body temperature.

Likewise, a number of environmental factors, such as changing temperature, weather patterns, an increase or decrease in food or water, or a decrease in a shelter can lead to changes within an organism. Many organisms are dependent on the seasons, hibernating or migrating in winter. These mechanisms and responses help them to survive and reproduce.

Examples

  • in plants is the ability of plants to sense changes in the length of daylight and to use this information to regulate growth and development.

For example, many plants use the length of daylight to time the onset of flowering. , such as poinsettias, will only flower when the days are shorter than a certain critical length, while , such as wheat, will only flower when the days are longer than a certain critical length. This ability allows plants to time their reproduction to coincide with optimal growing conditions.

  • is the ability of plants to sense changes in the direction of light and to use this information to orient their growth. For example, plants will grow towards the light in order to optimize their photosynthesis.

https://firebasestorage.googleapis.com/v0/b/fiveable-92889.appspot.com/o/images%2F-XECA5BpSTfJZ.jpg?alt=media&token=d9897ef8-e473-4f54-8dcf-55fa8b396a41

Source: Adobe

  • in animals refers to the ability of animals to move towards or away from a stimulus, such as light or a specific chemical.

For example, many insects are attracted to light, which they use to navigate towards food sources or mates.

  • in animals refers to the ability of animals to change the rate or direction of their movement in response to a stimulus, such as light or a specific chemical.

For example, when a cockroach detects an unpleasant odor, it will increase its rate of movement in order to escape from the source of the odor.

https://firebasestorage.googleapis.com/v0/b/fiveable-92889.appspot.com/o/images%2F-hNj3bQw2cR4z.jpg?alt=media&token=fed2d4b5-1555-4c71-b9a8-67441d99e58c

Source: Animal Behavior

  • Nocturnal and diurnal activity refer to the different patterns of activity that animals exhibit during the day and night. Nocturnal animals are active at night and sleep during the day, while diurnal animals are active during the day and sleep at night.

For example, lions are diurnal animals, while bats are nocturnal animals. These patterns of activity are usually determined by the availability of food and predators, as well as the temperature and light conditions.

  • is a physiological response to a perceived threat or danger. This response is characterized by the release of adrenaline and other hormones, which prepare the body for physical activity, such as fighting or running away. This response is triggered by the activation of the and it increases the heart rate, blood pressure and muscle tone.

https://firebasestorage.googleapis.com/v0/b/fiveable-92889.appspot.com/o/images%2F-TyZvCr6lfcs8.png?alt=media&token=6f7e7d24-c15b-4e35-b9cb-2277f0b20aa0

Source: Mount Marty

  • are the communication of danger by one organism to others of the same species.

For example, when a bird spots a predator, it will emit a specific alarm call that alerts other birds in the area to the danger. This allows them to take evasive action before the predator can attack. Some plants also have mechanisms to warn other plants of herbivory and will release chemical signals to warn nearby plants of an herbivore attack.

Organism to Organism: Communication is Key!

Organisms can also communicate with one another. Different species have their own highly evolved mechanisms of communication. This can involve the release of hormones, behavioral patterns, mating dances, warning calls, or any other number of responses. ❤️

https://firebasestorage.googleapis.com/v0/b/fiveable-92889.appspot.com/o/images%2Ftumblr_nx91y9YudG1sjwwzso1_540.gif?alt=media&token=6480bd83-eab3-4046-ba97-8890ebb4e256

Image courtesy of Giphy.

These forms of communications may be spurred by a physiological response from an organism, meaning something that occurs within themselves, such as hunger, or through an environmental change, such as the approaching of a predator. As a reminder, just like humans, many species communicate using verbal and nonverbal cues. This can involve audible warning signs and visible body language shifts. Some animal species have communication patterns that are far more complex than what we have.

Organisms often communicate changes that they sense in their environment in order to protect the members of their same species. For instance, prairie dogs are known to become very visible and give a loud warning call that can be heard by their own family members if a predator is approaching. While this may make them more susceptible to the predator, their genes will still be passed on by the family members that survive.

Connections to Evolution

Responses to information and communication of information are vital to and evolution. This is because the ability to sense and respond to environmental cues, as well as to exchange information with other individuals, can have a significant impact on an organism's survival and reproductive fitness. 💪

favors innate and that increase survival and reproductive fitness. For example, animals that are able to detect and avoid predators, or to find food and mates, are more likely to survive and reproduce than those that cannot. Similarly, plants that are able to sense and respond to changes in light intensity and direction, or to defend themselves against herbivores, are more likely to survive and reproduce than those that cannot.

also tends to increase the fitness of the individual and the survival of the population. For example, cooperative hunting, child-rearing, and care of the elderly in animals, and in plants and animals, such as pollination or seed dispersal, can increase the survival and reproduction of the individuals involved. This is because cooperation allows individuals to work together to achieve a common goal, such as obtaining food or protecting against predators, which can be more effective than working alone. 🐝

https://firebasestorage.googleapis.com/v0/b/fiveable-92889.appspot.com/o/images%2F-ktMJot0t3Yme.jpeg?alt=media&token=f084e51c-7c83-4abe-ae3d-c43690a87447

Source: ScienceDirect


-----

Key Terms to Review (20)

Behavioral Mechanisms

: Behavioral mechanisms refer to the actions or reactions of an organism in response to stimuli from its environment.

Communication in Organisms

: Communication in organisms refers to the transfer of information from one organism to another through signals or behaviors.

Cooperative Behavior

: Cooperative behavior refers to actions taken by organisms that benefit others in their group, often at a cost to themselves. This behavior is common in social species and contributes to the survival of the group as a whole.

Diurnal Activity

: Diurnal activity refers to the behavior of animals that are active during the day and rest or sleep at night.

Environmental Sensing

: Environmental sensing is the process by which organisms perceive and respond to certain changes in their environment.

Fight-or-Flight Response

: The fight-or-flight response is a physiological reaction that occurs in response to a perceived harmful event or threat to survival. It prepares an organism for fighting off harm or fleeing from danger.

Innate Behaviors

: Innate behaviors are those that occur naturally without any need for learning. They are instinctual and present at birth.

Kinesis

: Kinesis is a non-directional response where an organism's speed or activity level changes due to changes in their environment but not necessarily toward or away from any specific stimuli.

Learned Behaviors

: Learned behaviors are actions or behaviors that animals acquire through experience or observing others within their environment.

Long-Day Plants

: Long-day plants flower when nights are short; typically these types bloom in late spring or early summer when days are getting longer.

Mutualistic Relationships

: A mutualistic relationship is one where both organisms involved benefit from their interaction with each other.

Natural Selection

: Natural selection is a process in nature where organisms possessing certain genotypic characteristics that make them better adjusted to their environment tend to survive, reproduce, increase in number or frequency, and therefore, are able to pass on these favorable genetic traits to their offspring.

Nocturnal Activity

: Nocturnal activity refers to the behavior of animals that are active during the night and sleep during the day.

Photoperiodism

: Photoperiodism is the physiological reaction of organisms to the length of day or night. It triggers flowering, hibernation, migration and other behaviors.

Phototropism

: Phototropism is the growth or movement of a plant in response to light direction.

Physiological Mechanisms

: Physiological mechanisms refer to how living organisms' bodies function internally at both physical and chemical levels in response to their environments.

Predator Warnings

: Predator warnings are signals given by animals to alert others of potential threats from predators.

Short-Day Plants

: Short-day plants require a long period of darkness (shorter daylight) in each 24-hour cycle to induce flowering.

Sympathetic Nervous System

: The sympathetic nervous system is a part of the autonomic nervous system that prepares the body for action by triggering the fight-or-flight response.

Taxis

: Taxis is a directed movement towards or away from a stimulus such as light (phototaxis), heat (thermotaxis), or gravity (geotaxis).


© 2024 Fiveable Inc. All rights reserved.

AP® and SAT® are trademarks registered by the College Board, which is not affiliated with, and does not endorse this website.


© 2024 Fiveable Inc. All rights reserved.

AP® and SAT® are trademarks registered by the College Board, which is not affiliated with, and does not endorse this website.