Biology - Coordination and Response

Flashcards about Coordination and Response in Plants and Animals

Stimulus

A detectable change in the internal or external environment that influences a temporary increase of physiological activity or response in the whole plant or any part of plant.

Coordination in plants

The responses to external stimuli or environmental changes that are produced by the working of various organs in a systematic and controlled manner.

Plant hormones

Chemicals that undertake coordination and response in plants; also called plant growth regulators or phytohormones.

Growth

An irreversible increase in size of an individual cell or organ or its parts as a result of all the metabolic activities.

What are the three phases of growth in plants?

Meristematic, Elongation, and Maturation

What conditions are required by a plant for growth?

Light, Optimum temperature, Water, Oxygen, Mineral nutrients, Growth regulators, and Genetic factors

Development

A sequence of changes comprising the life cycle of an organism, during which structures and functions of organs or cells are changed.

Plant growth regulators

Organic compounds synthesized in one part of a plant in minute quantities and translocated to another part where it causes a physiological response; also called plant hormones or phytohormones.

Name three growth promoters.

Auxin, Gibberellin, and Cytokinin

Name two growth inhibitors.

Ethylene and Abscisic acid

List five physiological effects of auxin in plants.

Root inhibition, Parthenocarpy, Cell elongation, Abscission, and Cell division

List three physiological effects of gibberellin in plants.

Fruit growth, Stem and leaf growth, and Seed germination

Where does Cytokinin occur naturally?

Regions with high cell division, e.g., root apices. Coconut milk is a rich source.

List three physiological effects of cytokinin in plants.

Flowering, Promote lateral bud developments in dicots, and Development of the chloroplast.

List three physiological effects of ethylene in plants.

Stimulates ripening of fruits, causes drooping of leaves and flowers, and induces rapid growth of internodes and leaf bases.

List three physiological effects of abscisic acid in plants.

Causes abscission in leaves, flowers and fruits, includes synthesis of carotenoids, and acts as antagonist of all growth promoters.

Seed Dormancy

The internal inhibition of germination of a normal or viable seed even when it is placed under most favorable conditions required for its germination.

What are the causes of seed dormancy?

Hard seed coats impermeable to water and gases, presence of immature embryo, light sensitive seeds, and presence of germination inhibitors.

What are the types of seed germination?

Epigeal, Hypogeal, and Vivipary

Photoperiodism

Effect or requirements of relative length of day and night on flowering

What are the categories plants have been divided based on the duration of photoperiod?

Short day plants, Long day plants, and Day neutral plants

Photomorphogenesis

Plants exhibit different growth habits in dark and light; in the dark, they have elongated stems, undifferentiated chloroplasts and unexpanded leaves.

What photoreceptors perceive light in plants?

Phytochrome, cryptochrome and phototropin.

Coordination in animals

The process involved in the detection of stimuli by receptors, the integration of the information received, and the subsequent actions of the effectors to produce responses to the stimuli.

What are the two main body systems involved in coordination?

Nervous system and Endocrine system

Why is it necessary for animals to respond to stimuli?

To adapt to the environment, for protection from danger, for safety, and to regulate the internal environment by homeostasis.

What two systems make up the human nervous system?

Central nervous system and Peripheral nervous system.

What are the seven basic parts of the central nervous system?

Spinal cord, medulla, pons, cerebellum, midbrain, diencephalon, and cerebral hemispheres.

What does the forebrain comprise?

Cerebrum, thalamus and hypothalamus

What does the hindbrain consist of?

Cerebellum, pons and medulla oblongata

What are the four lobes of a cerebral hemisphere?

Frontal, parietal, temporal, and occipital

What is the function of the cerebrum?

Acts as the centers for intellect, learning and memory, consciousness, and language; it interprets and controls the response to sensory information.

What is the function of the thalamus?

Acts as the great relay station of the brain

What is the function of the hypothalamus?

Helps to regulate the body's internal environment, as well as certain aspects of behaviour. Contains neurones that control blood pressure, heart rate, body temperature, and basic drives (such as thirst and hunger) and emotions (such as fear, rage, and pleasure).

What is the function of the midbrain?

Involved in processing information from sensory neurones in the eyes, ears, and nose. Relays visual and auditory information between areas of the hindbrain and forebrain. Plays an important role in eye movement and control of skeletal muscles.

What is the function of the cerebellum?

Involved in the unconscious coordination of posture, reflexes, and body movements, as well as fine, voluntary motor skills. Receives information from specialized sensors, called proprioceptors, located within skeletal muscles and joints.

What is the function of the pons?

Serves as a relay centre between the neurones of the right and left halves of the cerebrum, the cerebellum, and the rest of the brain

What is the function of the medulla oblongata?

Coordinates many reflexes and automatic bodily functions that maintain homeostasis, including heart rate, constriction or dilation of blood vessels, and the rate and depth of breathing, swallowing, and coughing.