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Questions and Answers
Which type of plant response is characterized by non-directional movements to stimuli?
Which type of plant response is characterized by non-directional movements to stimuli?
What causes the differential growth in plant tropisms?
What causes the differential growth in plant tropisms?
In the context of migration, which of the following factors are important triggers for animals?
In the context of migration, which of the following factors are important triggers for animals?
What is the primary difference between taxes and kinesis in animal movement?
What is the primary difference between taxes and kinesis in animal movement?
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Which of the following statements about photoperiodism in plants is true?
Which of the following statements about photoperiodism in plants is true?
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What is an example of positive geotropism in plants?
What is an example of positive geotropism in plants?
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What mechanism allows the Venus flytrap to perform its nastic response?
What mechanism allows the Venus flytrap to perform its nastic response?
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Which of the following best describes the concept of allelopathy as seen in mature manuka trees?
Which of the following best describes the concept of allelopathy as seen in mature manuka trees?
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What is the primary role of internal biological clocks in organisms?
What is the primary role of internal biological clocks in organisms?
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Which of the following best describes the concept of zeitgeber?
Which of the following best describes the concept of zeitgeber?
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How do nocturnal behaviors contribute to the survival of organisms?
How do nocturnal behaviors contribute to the survival of organisms?
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In an experiment examining activity patterns, what was observed in organisms kept in constant darkness?
In an experiment examining activity patterns, what was observed in organisms kept in constant darkness?
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What effect does a phase shift have on an organism's biological rhythm following a light cycle change?
What effect does a phase shift have on an organism's biological rhythm following a light cycle change?
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Which of the following statements about intra-specific relationships is false?
Which of the following statements about intra-specific relationships is false?
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What are the potential costs associated with group living for organisms?
What are the potential costs associated with group living for organisms?
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Which statement about biological rhythms is true?
Which statement about biological rhythms is true?
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Study Notes
Level 3 Plants and Animals Biology Overview
- Topic focuses on how plants and animals respond to their external environment and the adaptive advantages of these responses.
- Two main environmental factors: biotic (living organisms) and abiotic (non-living elements).
Framework for Understanding Responses
- Responses can be categorized into three levels:
- Understanding: Describe the key terms and responses of organisms.
- Merit: Explain internal mechanisms leading to responses.
- Excellence: Link responses to adaptive advantages and contextual information.
Plant Responses
-
Nastic Responses:
- Non-directional movements to stimuli (e.g., Venus flytrap movement).
- Operate via changes in turgor pressure, not growth.
-
Tropisms:
- Directional growth towards or away from stimuli (e.g., roots growing down, shoots growing up).
- Controlled by auxins, which elongate cells differently in roots and shoots.
-
Examples of Key Tropisms:
- Positive geotropism: Roots grow towards gravity.
- Negative geotropism: Shoots grow against gravity.
Manuka Tree Example (2017 Exam)
- Understand tropisms in germinating seeds below soil:
- Positive and negative geotropism.
- Explore allelopathy in mature manuka trees:
- Release of leptospirome inhibits growth of neighboring plants, affecting competition for resources.
Animal Responses
-
Taxes and Kinesis:
- Kinesis: Non-directional movement in response to stimuli (e.g., changing speed).
- Taxes: Directional movement towards or away from stimuli (e.g., slaters move from light).
-
Orientation and Navigation:
- Migration involves two-way mass movement; homing is returning to a specific location.
- Animals prepare for migration through diet changes and utilize environmental cues (e.g., day length, temperature).
City Shearwater Example
- Individual migration from New Zealand to Northern Hemisphere:
- Approximate travel distances: up to 500 km per day.
- Understand triggers for migration: maturity, environmental signals.
Photoperiodism in Plants
- Synchronization of flowering based on day length:
- Plants react to light through phytochrome, existing in two forms (red and far-red).
- Short day plants flower in winter; long day plants flower in summer.
Actograms in Animals
- Monitoring animal activity over a period to identify biological rhythms:
- Assess patterns of activity and inactivity through time tracking.
- Analyze timing responses to environmental changes.
Adaptive Advantages
- Understanding responses contributes to survival and reproductive success.
- Orientation towards favorable conditions and maximizing resource access are crucial for both plants and animals.
- The costs of migration and energy use must be weighed against benefits for survival and reproduction.### Daily Rhythms and Circadian Rhythms
- Daily rhythms refer to the organism's activity cycle over a 24-hour period, often influenced by external environmental cues like light and dark.
- The term "circadian" is used when discussing internal biological clocks that regulate these rhythms.
- An actogram shows the activity pattern of organisms, revealing their active periods in relation to light and darkness.
Experiment on Activity Patterns
- Initial phase: Organisms observed under 12 hours of light and 12 hours of darkness exhibit nocturnal activity starting at hour 12.
- Subsequent phase: In constant darkness, organisms maintained a similar activity pattern, demonstrating that their rhythm is endogenous (internally driven).
- A free-running rhythm occurs when an organism's activity cycle persists without external cues, confirming their internal biological clock.
Zeitgeber and Phase Shifts
- Zeitgeber refers to environmental cues that sync biological rhythms with external conditions, primarily light and darkness.
- Removal of light cues led to slight shifts in activity patterns, illustrating how internal cues work in synchrony with environmental factors.
- Phase shifts, such as feeling out of sync after changes in the light cycle (e.g., jet lag), demonstrate the ability of organisms to adjust their internal clocks.
Adaptive Advantages of Biological Rhythms
- Nocturnal behavior helps avoid predators and maximize feeding efficiency.
- An internal clock allows organisms to anticipate environmental changes, fine-tuning their behavior for seasonal variations.
Intra-specific Relationships
- Intra-specific relationships involve interactions among individuals of the same species, often revolving around competition for resources.
- Territorial behavior minimizes competition and allows for exclusive resource access.
- Hierarchies within groups (alpha, beta, omega) reduce conflict over resources and promote cooperative behaviors.
Cooperative Behavior and Group Dynamics
- Group living can facilitate shared responsibilities (e.g., raising young), improving survival rates.
- Costs of group living include increased spread of disease and competition for food.
- Monogamous pair bonding enhances parental care, with both parents investing time and energy in offspring.
Inter-specific Relationships
- Types of interspecific relationships:
- Mutualism: Both species benefit (e.g., pollinators and flowers).
- Commensalism: One species benefits while the other remains unaffected (e.g., remora fish and sharks).
- Predation: The predator benefits while the prey is harmed.
- Competition: Resource struggle where no species fully wins.
Strategies for Survival
- Predators develop tactics (e.g., stealth, speed) to capture prey effectively.
- Prey strategies to avoid predation may include mimicry, where palatable species resemble unpalatable ones for protection.
Exam Preparation Tips
- Practice past exam questions to enhance understanding and application of concepts.
- Plan responses to questions within a time limit to improve organization and focus.
Overview of Plant and Animal Responses
- Emphasis on how plants and animals adapt to external environments for survival and reproductive success.
- Distinction between biotic factors (living organisms) and abiotic factors (non-living elements).
Framework for Understanding Responses
- Responses are categorized into three levels:
- Understanding: Defines key terms and organism responses.
- Merit: Explains internal mechanisms driving responses.
- Excellence: Connects responses to adaptive advantages and contextual factors.
Plant Responses
-
Nastic Responses:
- Non-directional movements in response to stimuli, such as the Venus flytrap.
- Driven by changes in turgor pressure rather than growth.
-
Tropisms:
- Directional growth towards or away from stimuli.
- Influenced by auxins that affect cell elongation in different plant parts.
-
Key Tropism Examples:
- Positive geotropism: Roots grow towards gravity.
- Negative geotropism: Shoots grow against gravity.
Manuka Tree Example
- Germinating seeds demonstrate positive and negative geotropism below soil.
- Mature manuka trees exhibit allelopathy by releasing leptospirome, inhibiting competitor plant growth.
Animal Responses
-
Taxes and Kinesis:
- Kinesis involves non-directional movement in response to stimuli, while taxes denote directional movement (e.g., slaters moving away from light).
-
Orientation and Navigation:
- Migration entails two-way mass movement, and homing is the return to a specific site.
- Animals adjust diets and respond to environmental cues, including day length and temperature, before migration.
City Shearwater Migration
- Shearwaters migrate from New Zealand to the Northern Hemisphere, traveling up to 500 km daily.
- Triggers for migration include maturity and environmental signals.
Photoperiodism in Plants
- Flowering synchronization in plants occurs based on day length, regulated by phytochrome.
- Short day plants bloom in winter while long day plants flower in summer.
Actograms in Animals
- Actograms track animal activity to identify biological rhythms and patterns of behavior in relation to environmental influences.
Adaptive Advantages
- Plant and animal responses enhance survival and reproductive success by orienting towards favorable conditions and maximizing resource access.
- Energy costs of migration must be balanced against reproductive benefits.
Daily and Circadian Rhythms
- Daily rhythms reflect 24-hour activity cycles influenced by light and dark.
- Circadian rhythms are regulated by internal biological clocks, which maintain activity patterns.
Experiment on Activity Patterns
- Initial observation in 12 hours of light and darkness shows nocturnal activity starting at hour 12.
- Constant darkness maintains activity patterns, indicating endogenous rhythms.
- Free-running rhythms reveal persistence of activity cycles without external cues.
Zeitgeber and Phase Shifts
- Zeitgeber are environmental cues, primarily light, that synchronize biological rhythms.
- Removal of light creates slight shifts in activity patterns, demonstrating the synergy of internal and external factors.
- Phase shifts illustrate the adjustment capabilities of organisms’ internal clocks, such as experiencing jet lag.
Adaptive Advantages of Biological Rhythms
- Nocturnal behaviors enhance feeding efficiency and reduce predator risks.
- Internal clocks aid organisms in anticipating environmental changes and adjusting for seasonal variability.
Intra-specific Relationships
- Intra-specific relationships explore interactions among individuals of the same species, focusing on resource competition.
- Territorial behaviors reduce competition, allowing exclusive access to resources.
Cooperative Behavior and Group Dynamics
- Group living promotes shared responsibilities, improving survival rates.
- The costs associated with group living include competition and social conflicts.
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Description
This quiz explores how plants and animals adapt to their external environments through various responses. It covers both biotic and abiotic factors influencing these adaptations, as well as internal mechanisms and the advantages they provide. Engage with topics such as nastic responses and tropisms to deepen your understanding of biological interactions.
