Homeostasis 1
Which type of sensory receptor detects changes in temperature?
Thermoreceptors
What chemical messenger is released by endocrine glands and transported through the bloodstream to target cells?
A hormone
Which Australian artist released Dance Monkey?
Tones and I
What physiological response causes the diameter of blood vessels near the skin to increase, allowing more heat to be lost?
Vasodilation
What hormone increases the amount of water reabsorbed by the kidneys?
Antidiuretic hormone (ADH).
What is the function of the myelin sheath surrounding an axon?
It insulates the axon and increases the speed of transmission of nerve impulses/action potentials.
What do each of these receptors detect:
Chemoreceptor, Photoreceptor, Mechanoreceptor, Nociceptor
Chemoreceptor → chemicals
Photoreceptor → light
Mechanoreceptor → mechanical stimuli such as pressure, touch or vibration
Nociceptor → potentially damaging stimuli/pain
What Netflix series features the characters Eleven, Mike and Dustin?
Stranger Things
What small structures on the surface of leaves regulate gas exchange and water loss?
Stomata
What is the name of the small gap between the presynaptic and postsynaptic neurons?
The synaptic cleft.
Name two physiological responses that help a human body increase its temperature when it becomes too cold.
Shivering and vasoconstriction.
What is the function of the waxy cuticle on a plant leaf?
It reduces water loss from the leaf by limiting evaporation.
How many bones in the adult human body?
206
What is the difference between a sensory neuron, interneuron and motor neuron?
Sensory neuron: carries impulses from sensory receptors to the CNS.
Interneuron: connects neurons within the CNS.
Motor neuron: carries impulses from the CNS to an effector.
At resting potential an Axon (neuron) is __________ charged inside and __________ charged outside
At resting potential an Axon (neuron) is negatively charged inside and positively charged outside
Kleptothermy, Torpor and adaptations are all examples of _____________ responses to thermoregulation
Behavioural responses
- Kleptothermy - Groups huddle to reduce SA:V and heat loss
- Torpor - Metabolic rate is lowered to save energy (Hibernation) - Adaptation - Animals adapt to their environment (e.g. not leave shade)
Explain what vasomotor control is?
Arterioles supplying the skin with warm blood can be constricted to reduce blood flow and heat loss. They can also be dilated to increase heat loss when the body is too warm. (Physiological mechanism)
In The Hunger Games, what district is Katniss Everdeen from?
District 12
Give an example of a structural feature that helps endotherms maintain thermoregulation?
Insulation - Layers of fur or feathers, thick layers of blubber
Shape and size - Adaptations to reduce SA:V and thus reduce heat loss
Brown fat - Packed with mitochondria and a rich blood supply to deliver heat generated to vital organs
Increased mitochondria- The more mitochondria, the more cellular respiration, the more heat generated
Why does a hormone only affect some cells in the body, even though the hormone may be transported throughout the entire body?
Only target cells displaying the specific receptor for that hormone can respond to it. Cells without the appropriate receptor generally do not respond.
What is happening in the axon membrane during depolarisation?
When a nerve is stimulated and the stimulus reaches the threshold the axon membrane opens and Sodium channels allow Na+ to move inside and become more positively charged. (This is called depolarisation).
A student exercises on a hot day. Their body temperature increases. Identify the following components of the feedback-control pathway:
Stimulus → Receptor → Effector → Response
Which blood type is known as the universal red blood cell donor?
O negative
Define what a positive feedeback loop is
Give an example of one
What stops a positive feedback loop?
Positive feedback loop intensifies the stimulus
Birth of a mammal
The stimulus is corrected (e.g. baby born)
Two plants are exposed to the same drought conditions. Plant A has a thick waxy cuticle and closes its stomata efficiently. Plant B has a thin cuticle and its stomata remain open. Which plant is more likely to maintain water balance? Justify your answer using two structural or homeostatic mechanisms.
Plant A is more likely to maintain water balance. Its thick cuticle reduces water loss from the leaf surface, while stomatal closure reduces transpiration through the stomata. Together, these mechanisms reduce water loss during drought.