Aim: What are the characteristics of living things? Topic: Conditions for life

What is BIOLOGY? -the study of life. What is an ORGANISM? - any living thing.

What is an Environment? -the surroundings of an organism which affects how it lives.

What do all organisms need to survive? CONDITIONS/FACTORS FOR LIFE: 1. SOURCE OF ENERGY - needed for life processes. - light, FOOD SUN **The SUN is the origin of almost all the energy available to all living things.

2.WATER -water makes up more than 65% of all organisms. -it dissolves & carries materials throughout an org. -many chemical reactions take place in water. -helps keep an organisms temperature stable.

3.GASES -found in the environment. -needed to perform life processes. -oxygen (O 2 ), carbon dioxide (CO 2 ) & nitrogen (N). 4.PROPER TEMPERATURE homeostasis - needed to maintain “homeostasis” or “dynamic equilibrium” which means to have a constant, stable internal environment.

5.PROPER HABITAT -a place to live and find all the other factors needed for to carry out the life processes.

What are the life processes? -processes that all living things must do in order to survive. THEY ARE: 1.METABOLISM 2.RESPONSE 3.GROWTH 4.MOVEMENT 5.REPRODUCTION

What is METABOLISM?? 1. Metabolism = total of all the chemical activities that occur in a living thing involving energy usage. e.g. Building substances. Breaking down substances. - in order for these chemical reactions to take place, organisms must take in food for energy.

What are the parts of METABOLISM? Nutrition: 1. INGESTION -taking in food. 2. DIGESTION -breaking down food. 3. EXCRETION - removal of wastes produced by an organism

4.RESPIRATION - process by which an organism changes some of the energy stored in food into a more usable form (ATP). CO 2 is produced as a waste product. Synthesis: **The reverse of respiration is PHOTOSYNTHESIS – the process by which plants take in CO 2, H 2 O, sunlight and make food. This produces O 2 as a waste product!

What is RESPONSE?? -a reaction to a stimulus. What is a stimulus? -any change in the internal or external environment of an organism (temperature, weather, light, predator). e.g. blink, leaves fall off a tree, leaves bend towards light

What is Homeostasis? Homeostasis is the body’s ability to maintain a constant internal environment. Examples include: –Maintenance of body temperature. –Maintenance of pH. –Maintenance of sugar level in the blood. –Maintenance of water level in the body. Failure to maintain homeostasis will result in the organism becoming sick or dying!

What is GROWTH? - building new parts for an organism during metabolism. - an increase in cell size. - replace or repair of dying or dead cells. - maturation e.g. a baby getting b i g g e r, fruit ripening

What is MOVEMENT? -a change in position. -a whole organism can move. -internal organs, fluid, blood can move. -cell parts and cells can move.

What is REPRODUCTION? - production of a new offspring or organism. 2 types: 1) sexual – 2 parents 2) asexual – 1 parent ** NOT needed for the individual organism to survive – just the species.

Summary: All forms of life share certain characteristics. Living things are able to move, perform complex chemical activities, grow, reproduce, and respond to stimuli.