Life Processes and Movements - Scholarly Flashcards
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What are the life processes involved in maintenance functions in living organisms?
These processes include movement growth response to environmental changes and coordination.
What is the notion associated with movement and life?
If we see something moving we tend to think that it is alive.
How do movements in plants differ from movements in animals?
In plants movements can be a result of growth (e.g. a seedling pushing through soil) while in animals movements are often not related to growth (e.g. a cat running).
Why do we associate visible movements with life?
Movement is often seen as a response to changes in the environment used by organisms to their advantage.
Provide examples of movements in animals that are not connected with growth.
Examples include a cat running children playing on swings and buffaloes chewing cud.
What is controlled movement in living organisms associated with?
Controlled movement is associated with the recognition of various events in the environment and the appropriate responses to them.
What systems provide control and coordination in multicellular organisms?
Specialised tissues are used to provide control and coordination activities.
What types of tissues provide control and coordination in animals?
Nervous and muscular tissues.
How is an urgent and dangerous situation like touching a hot object detected?
It is detected through specialised tips of nerve cells called receptors located in sense organs.
What are gustatory and olfactory receptors responsible for?
Gustatory receptors detect taste while olfactory receptors detect smell.
What happens when a nerve impulse travels in the body?
The impulse travels from the dendrite to the cell body along the axon and results in the release of chemicals at the synapse stimulating the next neuron.
What is a synapse?
A synapse is the gap between neurons where signals are transmitted from one neuron to another.
What role does nervous tissue play in the body?
Nervous tissue conducts information via electrical impulses from one part of the body to another.
What is a reflex action?
A reflex action is a sudden action in response to a stimulus often occurring without conscious thought.
What is a reflex arc?
A reflex arc is a neural pathway that controls reflex actions allowing for quick responses to stimuli.
What is the central nervous system?
The central nervous system consists of the brain and spinal cord which receive and process information from the body.
What are the three major parts of the brain?
The three major parts of the brain are the fore-brain mid-brain and hind-brain.
What functions does the fore-brain carry out?
The fore-brain processes sensory impulses interprets information and controls voluntary muscle movement.
What involuntary actions are controlled by the mid-brain and hind-brain?
Involuntary actions include blood pressure regulation salivation and digestion.
How does the body protect the brain?
The brain is protected by sitting inside a bony box (skull) and is surrounded by a fluid-filled balloon for shock absorption.
How do muscle cells move in response to nerve impulses?
Muscle cells change their shape and shorten in response to nervous electrical impulses.
What is the difference between voluntary and involuntary muscles?
Voluntary muscles can be controlled consciously; involuntary muscles operate without conscious control.
What types of movements do plants exhibit in response to stimuli?
Plants exhibit movements that are dependent on growth and movements that are independent of growth.
How do sensitive plants (touch-me-not) respond to touch?
Sensitive plants fold up and droop their leaves quickly in response to touch without involving growth.
What is the role of the brain in reflex actions?
The brain integrates signals and can influence responses but reflex actions can occur independently of brain processing for speed.
What types of receptors are involved in detecting taste and smell?
Gustatory receptors are involved in taste detection while olfactory receptors are involved in smell detection.
What happens at the synapse between two neurons?
A chemical signal is released that creates a similar electrical impulse in the next neuron.
What is the cerebellum responsible for?
The cerebellum is responsible for the precision of voluntary actions and maintaining posture and balance.
What happens when a bright light is focused on your eyes?
Nerve impulses are triggered that send signals to the brain for processing an appropriate response.
How do plants like the chhui-mui exhibit movement?
They respond to touch by folding their leaves which does not involve growth.
What is the function of the medulla in the hind-brain?
The medulla controls involuntary actions such as breathing and heart rate.
What happens when a sensitive plant is touched?
Movement occurs at a point different from the point of touch indicating that information about the touch must be communicated.
How do plants convey information about touch?
Plants use electrical-chemical means to communicate information from cell to cell without specialised tissue for conduction like in animals.
What causes movement in plant cells?
Some cells must change shape for movement to happen which involves changing the amount of water in them resulting in swelling or shrinking.
How do tendrils of climbing plants respond to touch?
When tendrils come in contact with a support the part in contact grows slower than the part away from the object causing the tendril to curl around it.
Define tropic movements in plants.
Tropic movements are directional movements in response to environmental stimuli such as light (phototropism) or gravity (geotropism).
What is phototropism?
Phototropism is the growth response of plants where shoots bend towards light and roots bend away from it.
What is geotropism?
Geotropism is the growth response of plants where roots grow downwards in response to gravity and shoots grow upwards and away from the earth.
What do hydrotropism and chemotropism refer to?
Hydrotropism refers to growth in response to water while chemotropism refers to growth in response to chemical stimuli.
Give an example of chemotropism.
The growth of pollen tubes towards ovules.
How do plants communicate information about stimuli?
Plants utilize chemical communication through hormones to coordinate growth and responses to environmental changes.
What is auxin and how does it function in plants?
Auxin is a plant hormone that helps cells grow longer and is synthesized at the shoot tip diffusing towards the shaded side of the plant when light is coming from one side.
What roles do gibberellins and cytokinins play in plant growth?
Gibberellins promote stem growth while cytokinins promote cell division and are found in areas of rapid cell division like fruits and seeds.
What is the function of abscisic acid in plants?
Abscisic acid inhibits growth and causes effects like wilting of leaves.
What is the role of adrenaline in animals?
Adrenaline is a hormone secreted from the adrenal glands helping the body prepare for ‘fight or flight’ responses by increasing heart rate and oxygen supply to muscles.
How do hormones and electrical impulses differ in their function in the body?
Hormones can reach all cells of the body and provide widespread changes while electrical impulses via nerve cells are limited to connected tissues.
What is the significance of the feedback mechanism in hormone secretion?
Feedback mechanisms regulate the timing and amount of hormone release such as insulin secretion in response to blood sugar levels.
What is the consequence of iodine deficiency in diet?
Iodine deficiency can lead to goitre characterized by a swollen neck due to insufficient thyroxin production by the thyroid gland.
What is the effect of growth hormone and its deficiency in childhood?
Growth hormone regulates growth and development; its deficiency in childhood can lead to dwarfism.
What hormones are involved in puberty?
Testosterone in males and oestrogen in females are responsible for the changes associated with puberty.
What is the function of insulin in the body?
Insulin regulates blood sugar levels; if not produced in proper amounts it can lead to diabetes.
What is the role of the hypothalamus in hormone regulation?
The hypothalamus releases hormones that stimulate the pituitary gland to release other hormones maintaining hormone levels in the body.
What functions does the endocrine system perform in animal bodies?
The endocrine system facilitates chemical coordination through hormones impacting various bodily functions and responses.
What is the difference between involuntary actions and reflex actions?
Involuntary actions occur without conscious control while reflex actions are automatic responses to stimuli involving a specific pathway.
How do nervous and hormonal mechanisms compare in control and coordination in animals?
Nervous mechanisms use electrical impulses for rapid responses while hormonal mechanisms use chemical signals for longer-lasting effects.
How does phototropism occur in plants?
Phototropism occurs when light causes auxin to redistribute leading to differential growth and bending towards the light.
What are the limitations of using electrical impulses for communication in animals?
Electrical impulses only reach cells connected by nervous tissue and cells take time to reset before transmitting new impulses.
