UNIT 8

• Responses to the Environment


  The ability of organisms to detect and respond to changes in their environment
• Behavioral mechanisms


  • Organisms can change their behavior in response to environmental cues, such as changes in temperature, light, or food availability
• Physiological mechanisms

  • Involve changes in the activity of genes, enzymes, and hormones in response to environmental cues
• Photoperiodism


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


  • The ability of plants to sense changes in the direction of light and to use this information to orient their growth
• Taxis

  • The directed movement of an organism towards or away from a stimulus such as light, heat, or gravity
• Kinesis

  • A non-directional response where an organism's speed or activity level changes due to changes in their environment
• Nocturnal activity

  The behavior of animals that are active at night and sleep during the day
• Diurnal activity


  The behavior of animals that are active during the day and sleep at night
• Fight-or-flight response

  A physiological response to a perceived threat or danger, characterized by the release of adrenaline and other hormones
• Predator warnings


  The communication of danger by one organism to others of the same species
• Communication in organisms

  The transfer of information from one organism to another through signals or behaviors
• Cooperative behavior

  Actions taken by organisms that benefit others in their group, often at a cost to themselves
• Innate behaviors

  Behaviors that occur naturally without any need for learning, instinctual and present at birth
• Learned behaviors


  Actions or behaviors that animals acquire through experience or observing others within their environment
• Long-day plants

  Plants that flower when nights are short, typically blooming in late spring or early summer
• Short-day plants


  Plants that require a long period of darkness (shorter daylight) in each 24-hour cycle to induce flowering
• Mutualistic relationships


  Relationships where both organisms involved benefit from their interaction with each other
• Natural selection


  The process where organisms possessing certain genotypic characteristics that make them better adjusted to their environment tend to survive, reproduce, and pass on these favorable genetic traits
• Sympathetic nervous system


  The part of the autonomic nervous system that prepares the body for action by triggering the fight-or-flight response