The Nature And Variety Of Living Organisms Flashcards
What is the acronym for the criteria that are true of all living organisms?
MRS C GREN
What does MRS C GREN stand for?
movement, respiration, sensitivity, control, growth, reproduction, excretion and nutrition
Why do organisms need food?
To provide energy, to carry out life processes
How to plants get nutrition?
Plants use sunlight, carbon dioxide and water to produce oxygen and glucose in the process of photosynthesis
How do animals get nutrition?
Animals consume other living organisms in order to obtain the energy they require
They break down larger complex molecules into simpler molecules through the process of digestion
Name 3 autotroph organisms
Plants, some bacteria and algae
Name 3 heterotroph organisms
Animals, most bacteria, fungi
How to producers obtain food?
They create their own food using photosynthesis
How to consumers obtain food?
They consume other organisms to obtain energy
What’s the difference between autotrophs and heterotrophs?
Autotrophs make their own food whereas heterotrophs obtain it from a range of food sources
What is respiration
Respiration is a chemical reaction carried out in all living organisms
What happens during respiration?
Energy is released from glucose either in the presence of oxygen (aerobic respiration) or the absence of oxygen (anaerobic respiration)
The reactions ultimately result in the production of carbon dioxide and water as waste products
Energy is transferred in the form of ATP
What is the equation for aerobic respiration
Glucose + oxygen —> carbon dioxide +water
What are metabolic reactions?
Chemical reactions that take place inside living cells
What is excretion?
The removal of toxic materials and substances from organisms
Give 3 examples of waste products excreted by animals?
Carbon dioxide, water, urea
Give 3 examples of waste products excreted by plants
Oxygen, carbon dioxide, water
What do plants excrete at night?
Carbon dioxide, when the rate of respiration exceeds the rate of photosynthesis. Water vapour is excreted through transpiration.
What’s the difference between excretion and egestion?
the waste products removed through excretion have originated from chemical reactions in the cells. However, the waste products produced in egestion are in the form of faeces and originate from the remains of the substances not absorbed during digestion.
What does the sensitivity of an organism refer to?
An organisms ability to detect and respond to stimuli in its surrounding, so it has best chances of survival
Which 2 systems allow animals to have sensitivity responses?
The nervous system (receptors, neurones and effectors) and the endocrine system (uses chemical messengers - hormones in blood)
Why is sensitivity in plants slower than in animals?
Plant responses are controlled by chemicals
Define geotropism
A plants responde to gravity which causes the roots to grow down into the soil
Define phototropism
A plants responde to light which causes shoots to grow towards sunlight
Define movement
An action by an organism causing a change of position or place
Define locomotion
The movement of an organism from place to place
What do plants use instead of locomotion?
Orientation (e.g. sunflowers)
Define homeostasis
When living organisms control their internal environment to keep conditions within required limits
Define thermoregulation
The control of body temperare (37 degrees centigrade for humans)
What mechanisms does the body use to control body temperature?
Vasoconstriction shivering if cold, vasodilation sweating of hot
Describe homeostasis in plants
Plants use transpiration: water evaporates from the stomata on the underside of the leaf, leading to heat loss.
