Humans

• What are the two types of responses in the human body?


  Hormonal and nervous responses
• What is the role of neurotransmitters at synapses?

  They pass nerve impulses from one neuron to the next
• What is a simple reflex arc?

  A pathway that involves sensory neurons, relay neurons, and motor neurons
• What is the function of the eye?

  To act as a receptor for light and focus images
• How does the skin help in temperature regulation?

  Through sweating, vasoconstriction, and vasodilation
• What is homeostasis?

  The maintenance of a stable internal environment
• How do organisms respond to changes in the environment?

  By using their nervous and hormonal systems
• How does Auxin affect plant movement towards light?

  It causes cells on the shaded side to elongate, bending the plant towards light
• What does the central nervous system consist of?

  The brain and spinal cord
• What is the function of sensory neurons?

  To send information from sense organs to the central nervous system
• What is the role of motor neurons?

  To transmit signals from the central nervous system to effectors
• What happens at a synapse?

  Neurotransmitters are released and bind to receptors on the next neuron
• What is the function of enzymes in the synaptic cleft?

  To destroy neurotransmitters quickly after their action
• What is a reflex action?

  An automatic and rapid response that does not involve the conscious brain
• What is the role of the coordination center in a reflex arc?

  To receive and process information from receptors
• How does the pupil reflex work in bright light?

  Circular muscles contract and radial muscles relax, causing the pupil to constrict
• What happens to the lens when focusing on distant objects?

  The ciliary muscle relaxes, suspensory ligaments pull tight, and the lens flattens
• What is vasodilation?

  The widening of blood vessels near the skin's surface to increase blood flow
• What is vasoconstriction?

  The narrowing of blood vessels near the skin's surface to decrease blood flow
• How does sweating help regulate body temperature?

  Sweat absorbs heat and cools the body through evaporation
• What role do skin hairs play when cold?

  They stand on end to trap air and insulate against heat loss
• What is the normal human body temperature?

  37°C
• How does the body respond when temperature is too high?

  By increasing blood flow to the skin and activating sweat glands
• How does the body respond when temperature is too low?

  By decreasing blood flow to the skin and causing hairs to stand on end
• What is the role of adrenaline?

  To prepare the body for 'fight or flight' response
• What is the role of insulin?

  To control blood glucose levels by converting glucose into glycogen
• What is the role of oestrogen?

  To regulate the female reproductive system and secondary sexual characteristics
• What is the role of testosterone?

  To regulate the male reproductive system and secondary sexual characteristics
• What is the role of FSH?

  To stimulate egg maturation and oestrogen production in females
• What is the role of LH?

  To trigger ovulation and stimulate oestrogen release in females
• What is the role of progesterone?

  To maintain the thickness of the uterus lining and prevent further egg maturation
• How are hormones transported to their target organs?

  Through the bloodstream
• How does insulin affect blood glucose levels?

  It lowers blood glucose levels by allowing glucose to enter liver cells
• How do FSH, oestrogen, and LH control the menstrual cycle?

  FSH stimulates oestrogen production and egg maturation, while LH triggers ovulation
• What is the journey of light through the eye?

  Light passes through the cornea and lens to focus on the retina
• What is accommodation in the eye?

  The process by which the lens changes shape to focus on objects at different distances
• What happens to the lens when focusing on close objects?

  The ciliary muscle contracts, suspensory ligaments loosen, and the lens becomes thicker
• How does the pupil reflex control light entering the eye?

  By contracting or relaxing the radial and circular muscles
• What is the blind spot in the eye?

  A part of the retina without light receptors where no image is detected
• How can you find your blind spot?

  By looking at an X while moving a dot out of your peripheral vision