Higher Biology - Unit 2.4

​Unit 2.4 Conformers and Regulators

​Conformers and Regulators

​The maintaining of an organism's metabolic rate is effected by abiotic factors such as: -Temperature -pH -Salinity

​Conformers and Regulators

​Organisms can be categorised into 2 broad groups...

​Conformers are dependant upon the changes in the external environment

​Regulators are capable of controlling their internal environment regardless of external environmental change

​Conformers

​-Low metabolic costs

-Are able to withstand change in the external environment

-Conformers must change their behaviour in order to survive in extreme circumstances

-Some decrease their activity when the temperature falls. Lizards for example bask in the sun to change their temperature to optimum

​Regulators

​-High metabolic rates

-They can withstand changes to the external environment because they can control their internal environment (requires energy)

-They use a fundamental process to survive called Homeostasis

Multiple Choice

A conformer's metabolic cost is...

• Low

• High

Multiple Choice

A Regulator's metabolic cost is

• High

• Low

Multiple Choice

Which of the following organisms is not a regulator

• Crab

• Camel

• Human

• Polar bear

• Chimpanzee

​Homeostasis

​-The hypothalamus is the body's temperature monitoring centre in the brain. It is sensitive to nerve impulses that come from receptors in the skin -During the process the hypothalamus sends nerve impulses to the effectors to change the temperature of the body. -Effectors can include sweat glands, muscles, and blood vessels around the body

​Thermoregulation

​The body can stop overheating by: Vasodilation - Blood vessels allow blood to flow to skin surface where heat is lost. In other words they become wider. Increased sweat rate - Heat can be lost through turning sweat to vapour which lowers body temperature Decrease in metabolic rate - If the metabolic rate is lower, less heat is produced

​Thermoregulation

​The body temperature can increase by:

​Vasoconstriction - Blood vessels are restricted and blood flow to skin stops so less heat is lost. In other words they become more narrow Hair erector muscles contract - Hairs stand up to trap any layer of warmer air next to the skin Shivering - Skeletal muscles around the body repeatedly contract. This generates heat

Multiple Choice

Vasolidation is a way to...

• Stop the body overheating

• To increase the body's temperature

Multiple Choice

Shivering is a way to...

• increase the body temperature

• decrease the body temperature

Multiple Choice

Which of the following is not a way to increase body temperature?

• Decrease in metabolic rate

• Hair erector muscles contraction

• Shivering

• Vasoconstriction

​List of Terms

​Conformer - An organism that is dependant upon the changes in the external environment

Regulator - An organism that can control its internal environment based on the changes in the external environment

Thermoregulation - Use of negative feedback in regulation of body temperature in animals

Hypothalamus - Temperature monitoring centre in the brain

Homeostasis - Maintenance of an optimum body temperature

Vasoconstriction - Narrowing of blood vessels to increase body temperature

Vasodilation - Widening of blood vessels to decrease body temperature

​END OF KEY AREA