iGCSE Biology Section 2 lesson 7

1. iGCSE Biology Section 2 lesson 7

2. Content Section 2 Structures and functions in living organisms a) Levels of organisation b) Cell structure c) Biological molecules d) Movement of substances into and out of cells e) Nutrition f) Respiration g) Gas exchange h) Transport i) Excretion j) Coordination and response

3. Content j) Coordination and response 2.77 understand that organisms are able to respond to changes in their environment 2.78 understand that homeostasis is the maintenance of a constant internal environment and that body water content and body temperature are both examples of homeostasis 2.79 understand that a coordinated response requires a stimulus, a receptor and an effector Flowering plants 2.80 understand that plants respond to stimuli 2.81 describe the geotropic responses of roots and stems 2.82 describe positive phototropism of stems Humans 2.83 describe how responses can be controlled by nervous or by hormonal communication and understand the differences between the two systems 2.84 understand that the central nervous system consists of the brain and spinal cord and is linked to sense organs by nerves 2.85 understand that stimulation of receptors in the sense organs sends electrical impulses along nerves into and out of the central nervous system, resulting in rapid responses 2.86 describe the structure and functioning of a simple reflex arc illustrated by the withdrawal of a finger from a hot object 2.87 describe the structure and function of the eye as a receptor 2.88 understand the function of the eye in focusing near and distant objects, and in responding to changes in light intensity 2.89 describe the role of the skin in temperature regulation, with reference to sweating, vasoconstriction and vasodilation 2.90 understand the sources, roles and effects of the following hormones: ADH, adrenaline, insulin, testosterone, progesterone and oestrogen. Lesson 7 j) Coordination and response

4. Content j) Coordination and response 2.77 understand that organisms are able to respond to changes in their environment 2.78 understand that homeostasis is the maintenance of a constant internal environment and that body water content and body temperature are both examples of homeostasis 2.79 understand that a coordinated response requires a stimulus, a receptor and an effector Flowering plants 2.80 understand that plants respond to stimuli 2.81 describe the geotropic responses of roots and stems 2.82 describe positive phototropism of stems Humans 2.83 describe how responses can be controlled by nervous or by hormonal communication and understand the differences between the two systems 2.84 understand that the central nervous system consists of the brain and spinal cord and is linked to sense organs by nerves 2.85 understand that stimulation of receptors in the sense organs sends electrical impulses along nerves into and out of the central nervous system, resulting in rapid responses 2.86 describe the structure and functioning of a simple reflex arc illustrated by the withdrawal of a finger from a hot object 2.87 describe the structure and function of the eye as a receptor 2.88 understand the function of the eye in focusing near and distant objects, and in responding to changes in light intensity 2.89 describe the role of the skin in temperature regulation, with reference to sweating, vasoconstriction and vasodilation 2.90 understand the sources, roles and effects of the following hormones: ADH, adrenaline, insulin, testosterone, progesterone and oestrogen. Lesson 7 j) Coordination and response

5. Content j) Coordination and response 2.77 understand that organisms are able to respond to changes in their environment 2.78 understand that homeostasis is the maintenance of a constant internal environment and that body water content and body temperature are both examples of homeostasis 2.79 understand that a coordinated response requires a stimulus, a receptor and an effector Flowering plants 2.80 understand that plants respond to stimuli 2.81 describe the geotropic responses of roots and stems 2.82 describe positive phototropism of stems Humans 2.83 describe how responses can be controlled by nervous or by hormonal communication and understand the differences between the two systems 2.84 understand that the central nervous system consists of the brain and spinal cord and is linked to sense organs by nerves 2.85 understand that stimulation of receptors in the sense organs sends electrical impulses along nerves into and out of the central nervous system, resulting in rapid responses 2.86 describe the structure and functioning of a simple reflex arc illustrated by the withdrawal of a finger from a hot object 2.87 describe the structure and function of the eye as a receptor 2.88 understand the function of the eye in focusing near and distant objects, and in responding to changes in light intensity 2.89 describe the role of the skin in temperature regulation, with reference to sweating, vasoconstriction and vasodilation 2.90 understand the sources, roles and effects of the following hormones: ADH, adrenaline, insulin, testosterone, progesterone and oestrogen. Lesson 7 j) Coordination and response

6. Responding to our environment

7. Responding to our environment LIGHT receptors in the EYES

8. Responding to our environment LIGHT receptors in the EYES SOUND receptors in the EARS

9. Responding to our environment LIGHT receptors in the EYES SOUND receptors in the EARS CHANGE OF POSITION receptors in the EARS (balance)

10. Responding to our environment LIGHT receptors in the EYES TASTE receptors in the TONGUE SOUND receptors in the EARS CHANGE OF POSITION receptors in the EARS (balance)

11. Responding to our environment LIGHT receptors in the EYES TASTE receptors in the TONGUE SOUND receptors in the EARS SMELL receptors in the NOSE CHANGE OF POSITION receptors in the EARS (balance)

12. Responding to our environment LIGHT receptors in the EYES TASTE receptors in the TONGUE SOUND receptors in the EARS SMELL receptors in the NOSE CHANGE OF POSITION receptors in the EARS (balance) TOUCH, PRESSURE and TEMPERATURE receptors in the SKIN

13. Responding to our environment The pathway:

14. Responding to our environment The pathway: Stimulus Receptor Coordinator Effector Response

15. Responding to our environment The pathway: Stimulus Receptor Coordinator Effector Response Change in the environment Detect stimuli Central nervous system Muscles or glands Action taken

16. Responding to our environment The pathway: Stimulus Receptor Coordinator Effector Response Change in the environment Detect stimuli Central nervous system Muscles or glands Action taken Hot pan Temperature receptors in the skin Central nervous system Muscles in arms Hand pulled away

17. Responding to our environment The pathway: Stimulus Receptor Coordinator Effector Response Change in the environment Detect stimuli Central nervous system Muscles or glands Action taken Hot pan Temperature receptors in the skin Central nervous system Muscles in arms Hand pulled away Responses can be either conscious or reflex

18. Controlling our internal environment Removal Carbon dioxide Product of respiration, removed by the lungs

19. Controlling our internal environment Removal Carbon dioxide Product of respiration, removed by the lungs Urea Produced by the liver, removed by the kidneys

20. Controlling our internal environment Controlled Water content Loss – lungs, sweating, urine Gain - drinking

21. Controlling our internal environment Controlled Water content Loss – lungs, sweating, urine Gain - drinking Ion content (eg. sodium) Loss – lungs, sweating, urine Gain – drinking, eating

22. Controlling our internal environment Controlled Water content Loss – lungs, sweating, urine Gain - drinking Ion content (eg. sodium) Loss – lungs, sweating, urine Gain – drinking, eating Temperature (37oC) Increase – shivering, shut down capillaries Decrease – sweating, open up capillaries

23. Controlling our internal environment Controlled Water content Loss – lungs, sweating, urine Gain - drinking Ion content (eg. sodium) Loss – lungs, sweating, urine Gain – drinking, eating Temperature (37oC) Increase – shivering, shut down capillaries Decrease – sweating, open up capillaries Blood glucose Increase - hormone GLUCAGON Decrease – hormone INSULIN

24. Controlling our internal environment Controlled Water content Loss – lungs, sweating, urine Gain - drinking Ion content (eg. sodium) Loss – lungs, sweating, urine Gain – drinking, eating Temperature (37oC) Increase – shivering, shut down capillaries Decrease – sweating, open up capillaries HOMEOSTASIS = maintenance of a constant internal environment Blood glucose Increase - hormone GLUCAGON Decrease – hormone INSULIN

25. Content j) Coordination and response 2.77 understand that organisms are able to respond to changes in their environment 2.78 understand that homeostasis is the maintenance of a constant internal environment and that body water content and body temperature are both examples of homeostasis 2.79 understand that a coordinated response requires a stimulus, a receptor and an effector Flowering plants 2.80 understand that plants respond to stimuli 2.81 describe the geotropic responses of roots and stems 2.82 describe positive phototropism of stems Humans 2.83 describe how responses can be controlled by nervous or by hormonal communication and understand the differences between the two systems 2.84 understand that the central nervous system consists of the brain and spinal cord and is linked to sense organs by nerves 2.85 understand that stimulation of receptors in the sense organs sends electrical impulses along nerves into and out of the central nervous system, resulting in rapid responses 2.86 describe the structure and functioning of a simple reflex arc illustrated by the withdrawal of a finger from a hot object 2.87 describe the structure and function of the eye as a receptor 2.88 understand the function of the eye in focusing near and distant objects, and in responding to changes in light intensity 2.89 describe the role of the skin in temperature regulation, with reference to sweating, vasoconstriction and vasodilation 2.90 understand the sources, roles and effects of the following hormones: ADH, adrenaline, insulin, testosterone, progesterone and oestrogen. Lesson 7 j) Coordination and response

26. Plant responses to the environment

27. Plant responses to the environment LIGHT

28. Plant responses to the environment LIGHT MOISTURE

29. Plant responses to the environment LIGHT GRAVITY MOISTURE

30. Plant responses to the environment LIGHT GRAVITY MOISTURE PHOTOTROPISM = growth response to light

31. Plant responses to the environment LIGHT GRAVITY MOISTURE PHOTOTROPISM = growth response to light GEOTROPISM = growth response to gravity

32. Plant responses to the environment Roots are positively geotropic – they grow in the direction of gravity

33. Plant responses to the environment Shoots are negatively geotropic – they grow away from the direction of gravity Roots are positively geotropic – they grow in the direction of gravity

34. Plant responses to the environment Shoots are positively phototropic – they grow in the direction of light

35. Plant responses to the environment GEOTROPISM – response to gravity Germinating seedling

36. Plant responses to the environment GEOTROPISM – response to gravity Plant growth is controlled by hormones – these are produced at the growing points of shoots and roots Germinating seedling

37. Plant responses to the environment GEOTROPISM – response to gravity In the shoot, the hormone is produced at the tip. It travels down through the shoot and stimulates the growth of cells on the lower side. The shoot therefore grows upwards, away from gravity. Germinating seedling

38. Plant responses to the environment GEOTROPISM – response to gravity In the shoot, the hormone is produced at the tip. It travels down through the shoot and stimulates the growth of cells on the lower side. The shoot therefore grows upwards, away from gravity. In the root the hormone is again produced at the tip. It travels up through the root and slows down the growth of cells on the lower side. The root therefore grows downwards, towards the force of gravity. Germinating seedling

39. Plant responses to the environment PHOTOTROPISM – response to light LIGHT Growing shoot

40. Plant responses to the environment PHOTOTROPISM – response to light LIGHT Growing shoot

41. Plant responses to the environment PHOTOTROPISM – response to light In shoots, light causes the hormone to accumulate on the side away from the light LIGHT Growing shoot

42. Plant responses to the environment PHOTOTROPISM – response to light LIGHT The hormone stimulates the growth of cells on the side away from the light, so the shoot grows towards the light. Growing shoot

43. Plant responses to the environment Commercial uses of plant hormones:

44. Plant responses to the environment • Commercial uses of plant hormones: • rooting compound – encourages the growth of roots in stem cuttings.

45. Plant responses to the environment • Commercial uses of plant hormones: • rooting compound – encourages the growth of roots in stem cuttings. • ripening hormone – enables plants to ripen at the same time. Sprayed on the crop, often while being transported.

46. Plant responses to the environment • Commercial uses of plant hormones: • rooting compound – encourages the growth of roots in stem cuttings. • ripening hormone – enables plants to ripen at the same time. Sprayed on the crop, often while being transported. • selective weedkillers – act on target plants, disrupting their growth.

47. Content j) Coordination and response 2.77 understand that organisms are able to respond to changes in their environment 2.78 understand that homeostasis is the maintenance of a constant internal environment and that body water content and body temperature are both examples of homeostasis 2.79 understand that a coordinated response requires a stimulus, a receptor and an effector Flowering plants 2.80 understand that plants respond to stimuli 2.81 describe the geotropic responses of roots and stems 2.82 describe positive phototropism of stems Humans 2.83 describe how responses can be controlled by nervous or by hormonal communication and understand the differences between the two systems 2.84 understand that the central nervous system consists of the brain and spinal cord and is linked to sense organs by nerves 2.85 understand that stimulation of receptors in the sense organs sends electrical impulses along nerves into and out of the central nervous system, resulting in rapid responses 2.86 describe the structure and functioning of a simple reflex arc illustrated by the withdrawal of a finger from a hot object 2.87 describe the structure and function of the eye as a receptor 2.88 understand the function of the eye in focusing near and distant objects, and in responding to changes in light intensity 2.89 describe the role of the skin in temperature regulation, with reference to sweating, vasoconstriction and vasodilation 2.90 understand the sources, roles and effects of the following hormones: ADH, adrenaline, insulin, testosterone, progesterone and oestrogen. Lesson 7 j) Coordination and response

48. Control of response in humans

49. Control of response in humans Our responses are controlled by both the nervous system and the endocrine system

50. Control of response in humans Our responses are controlled by both the nervous system and the endocrine system So what are the differences between the two?