Homestatis And Excretion Flashcards
Suggest how excretion may occur in simple organisms such as amoeba?
Diffusion / contractile vacuole
Name two excretory products other than water and give a location in body in which it is produced?
Urea - liver
Co2 - cells [respiration]
What is the effect of an increase in metabolic rate in response to falling external temperatures?
Generates heat
What term is used to describe animals that can vary their metabolic rate significantly?
Endotherms
Suggest how animals that cannot significantly vary their metabolic rate may respond to falling external temperatures?
Hibernate
What is piloerection?
Erector muscles contract causing hairs to stand up on skin
How is piloerection an important response to falling external temperatures?
A layer of warm air is trapped close to the skin and this layer of air acts as an insulator, reducing heat loss in the body
Explain how vasoconstriction can be an important response to falling external temperatures
Less blood flows close to the surface as blood vessels contract and there is reduced heat loss
What is the main source of heat for an endotherm?
Metabolism
What is the relationship between an endotherm’s body temperature and environment temperature
Environment temp - affects enzyme activity which is required for metabolism
What is the main source of an ectotherm’s body heat?
Environment
Suggest a relationship between an ectotherm’s body temperature and environment temperature?
They gain or lose heat from or to environment [temp]
State how the liver contributes to homeostasis
By the absorption of glucose
Release of glucose
State how the lungs contribute to homeostasis
Excretes water and co2
State how nephrons of kidneys contribute to homeostasis
Excretion of water and salts
Suggest an advantage of being an endotherm
Activity independent of env temp
Adaption of ectotherm
Butterflies and moths may orient their wings to maximize exposure to solar radiation in order to build up heat before take-off
Why is there a drop in body temperature late at night?
Human body temp drops when sleep due to inactivity
Why do children typically have higher body temperatures than adults?
Growing - more cell division
High metabolism
Mention one method of excretion in flowering plants
Through stomata [O2]
Name the blood vessel that supplies blood to the kidney and from which blood vessel does it arise from?
Renal artery and from aorta
In which cavity are the kidneys located?
Abdomen / abdominal
Name one substance other than water excreted in the urine
Urea
Salts
Give a feature of a kidney that indicates it is an exocrine gland?
Does not produce hormones