Coordination Flashcards
Why do organisms need to respond to change and what are the two types of changes
espond to changes in the internal or external environment (stimuli) for survival
There are two types of response: chemical and nervous
What is nervous change and who is responsible for it
nervous system is responsible for nervous change it allows the body to respond to stimuli in the internal and external environment and is coordinated by the brain and / or spinal cord
What is chemical change and who is responsible for it
The endocrine system is responsible for chemical change it also allows the body to respond to stimuli in the external and internal environment and is coordinated by glands throughout the body
What is homeostasis and why is it required with examples and
Homeostasis is the maintenance of a constant internal environment
It necessary to maintain optimal conditions for all cell function throughout the body
1.blood glucose concentration
2.body temperature
3.water levels
What do all control systems have and their function
- Receptors = detect stimuli (a sound, an image, a change in pressure on the skin, paind, a change in body temperature etc)
- Coordination center = the brain, spinal cord, pancreas or pituitary gland, which receives and processes information from receptors around the body
- Effectors = bring about response which restore optimum levels such as core body temperature or react to stimulus to prevent harm. Effectors include muscles and glands. and responses include muscle contractions or hormone release.
What stimuli do plants respond to and how and where can they grow and what are the changes know as
- respond to light, water, gravity.
- are usually much slower than animals and by producing a growth hormone called auxin which controls the direction of growth of roots or stems.
- towards a stimulus (known as a positive response) or away from a stimulus (known as a negative response), and changes known as tropisms
What is the name of the responses to gravity ligth and water stimuli
gravity : geotropism
light : phototropism
water : hydrotropism
Describe the geotropic and phototropic responses of roots and stems
- very important to a plant that its roots and shoots grow in the right directions
1. Shoot must grow upwards, away from gravity towards light therefore is known as positive phototropism and negative geotropism
2. Roots need to grow downwards away from light and towards gravity therefore is known as negative phototropism and positive geotropism.
What is the role of auxin in the phototropic response of stems and how does it work
*auxin : role of auxin in the phototropic response of stems
it mostly made up in growing stems and roots and can diffuse to other parts of the stems or roots.
1. Auxin make the cells behind tip get longer, more the auxin the faster they will grow.
2. If light is shining on plant the auxin is distributed evenly so all cells grow at same rate.
3. if light is shining more on one side, the auxin in the tip concentrates on the shady side, making the cells on that side grow faster than the cells on the sunny side
4. the unequal growth will result to the plant bending towards one side.
Investigating phototropic responses if tips have been removed
reason: This proves auxin is made in the tips, and if the seedling still grows towards light auxin is made elsewhere.
effect on auxin concentration: no auxin is produced
Result: The stems don’t grow longer.
Investigating phototropic responses if no light reaches tips
reason: Proves it is the effect of light on auxin that causes phototropism
effect on auxin concentration: equal concentration of auxin on both sides
result: The stems grow evenly and longer on both sides.
Investigating phototropic responses if more light reaches side of the tips
reason: This proves that shoots grow towards the light
effect on auxin concentration: Greater concentration of auxin on the shaded side
result: Cells on darker side grow of the stems grow longer.
What are the two main methods of transmitting information around the body and controlling responses:
the nervous system and via the endocrine system
What does the nervous system consist of, the type of message it sends, method of transmission, effectors, speed of transmission and length of effect
made of: central nervous system (CNS) = Brain spinal cord perpheral nervous system (PNS) = Nerves type of message: electrical impulse method of transmission: nerve cells effectors: muscles or glands speed of transmission: very fast length of effect: Short- until nerve impulses stop
What does the endocrine system consist of, the type of message it sends, method of transmission, effectors, speed of transmission and length of effect
made of: glands
type of message: Chemical hormone
method of transmission: Bloodstream
effectors: target cells in specific tissue
speed of transmission: slower
length of effect: Longer- until hormone is broken down