Unit 6 - Organisms respond to changes in their internal and external environments

Question 1

Homeostasis defintion

Answer 1

maintaining a constant internal environment within restricted limits in organisms

Question 2

What happens when there is an increase in body temperature?

Answer 2

• receptors (skin, hypothalamus) detect change
• hypothalamus
• sweat glands, vasodilation, hairs lie flat

Question 3

What happens when there is a decrease in body temperature?

Answer 3

• receptors (skin, hypothalamus) detect change
• hypothalamus
• vasoconstriction, shivering, hairs erect

Question 4

Vasodilation

Answer 4

arterioles dilate so blood in capillaries flows near surface of skin

Question 5

Vasoconstriction

Answer 5

arterioles constrict so blood in capillaries flows further from the surface of the skin

Question 6

Glycogenesis

Answer 6

glucose to glycogen

Question 7

Glycogenolysis

Answer 7

liver breaks down glycogen to glucose

Question 8

Gluconeogenesis

Answer 8

production of glucose from other sources e.g. glycerol, pyruvate and amino acids

Question 9

What are the specialised cells in the pancreas called?

Answer 9

islets of langerhans

Question 10

alpha cells

Answer 10

make and secrete glucagon when there is a low blood glucose conc

Question 11

beta cells

Answer 11

make and secrete insulin when there is a high blood glucose conc

Question 12

What does insulin stimulate?

Answer 12

• glycogenesis
• increased absorption rate (activates carrier proteins)
• increased respiratory rate
• fat

Question 13

What does glucagon stimulate?

Answer 13

• gluconeogenesis
• glycogenolysis

Question 14

What is the cause of Type I diabetes?

Answer 14

pancreas does not make enough insulin

Question 15

What is the effect of Type I diabetes?

Answer 15

uncontrolled blood glucose concentration, kidneys excrete glucose in urine

Question 16

What are symptoms of Type I diabetes?

Answer 16

thirsty, frequent urination, lack energy, tired, loss of weight

Question 17

What is the treatment for Type I diabetes?

Answer 17

insulin injections, transplants, adult stem cells and genetic engineering

Question 18

What is the cause of Type II diabetes?

Answer 18

insulin is made but less and cells stop responding to the insulin as receptors are less sensitive/ responsive

Question 19

What are risk factors of Type II diabetes?

Answer 19

people over the age of 40, obesity, lack of exercise, genetics

Question 20

What are the symptoms of Type II diabetes?

Answer 20

thirsty, lack energy, tired, loss of weight

Question 21

What is the treatment for Type II diabetes?

Answer 21

balanced diet, lose weight, regular exercise, drugs to help insulin work

Question 22

What is an auto-immune disease?

Answer 22

lymphocytes produce antibodies which destroy their own body cells