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

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Which category of organisms are dependant on their external evironment

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Which category of organisms are able to control their internal environments?

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

Fill in the Blank

What is the name of the body's temperature moderating centre in the brain?

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

Fill in the Blank

Temperature monitoring centre in the brain

Fill in the Blank

Maintenance of an optimum body temperature

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Use of negative feedback in regulation of body temperature in animals

Fill in the Blank

An organism that is dependant upon the changes in the external environment

Fill in the Blank

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

Fill in the Blank

Widening of blood vessels to decrease body temperature

Fill in the Blank

Narrowing of blood vessels to increase body temperature

​END OF KEY AREA