Biology A2 Unit 1 Flash Cards

Question	Answer
Define negative feedback	A process in which a parameter brings about the reversal of change so the parameter is kept fairly constant
Define postive feedback	A process in which any change in a parameter brings about an increase in that change
Define Homeostasis	The maintenance of a constant internal environment despite external changes
What is an autotroph?	An organism that makes its own food using simple inorganic molecules (such as CO2, H2O etc) and energy
What is a heterotroph?	An organism that gains its nutrients from complex organic molecules. / It digests them to simpler soluble molecules before respiring some of them to obtain energy or using products of digestion to synthesise the organic molecules it needs.
What is are photosynthetic pigments?	Chemicals that absorb light energy, found in the thylakoid membranes of chloroplasts, in photosystems. /Each pigment absorbs energy associated with light of a specific wavelength
What is a respiratory substrate?	An organic substance that can be used for respiration

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	Created by Zoeee over 10 years ago