Properties of Life

CHARACTERISTICS OF LIFE

MR. RHOGE 

METABOLISM - sum of all chemical reactions 

RESPONSE TO STIMULUS which is anything that can be detected and bring a response 

1. TROPISM - response with direction 

• POSITIVE TROPISM - toward the stimulus 
• NEGATIVE TROPISM - away from stimulus 

ex: geotropism - gravity, phototropism - light

2. NASTIC RESPONSE - response with no direction 

ex: makahiya, venus fly-trap 

REPRODUCTION - production of new offspring 

1. SEXUAL - genetically diverse, with partner, slow 

2. ASEXUAL - genetically conserved, without partner, fast 

HOMEOSTASIS - internal balance 

ORGANIZATION 

atom -> molecule -> organelle -> cell -> tissue -> organ -> organ system -> organism

GENETIC MATERIAL - DNA 

EVOLUTION - changes over several generations 

VIRUS - non-living organism: 

(1) requires a host to reproduce 

(2) Genetic material only without cells of their own 

CHEMICAL BASIS OF LIFE

Chemical Bonds

1. INTRAMOLECULAR BONDS - between atoms; strong 

(1) IONIC BOND - transfer of electrons 

(2) COVALENT BOND - sharing of electrons 

2. INTERMOLECULAR BONDS - between molecules; weak 

(1) DIPOLE-DIPOLE BONDS - molecules have polar covalent bonds…