What is Life?

DNA

a giant molecule consisting of the sugar deoxyribose, phosphates, and nitrogen bases; contains the coded genetic information

organelle

a small structure within the cell that serves specialized functions

metabolism

all of the chemical reactions in the organism for maintenance of the processes of life

SELECT ALL THAT APPLY: Characteristics that are always present in living organisms are ___.

complexity homeostasis* metabolism* heredity* movement cells* sensitivity reproduction*

The ability of an organism to change internally or externally in relation to changes in the environment is called ___.

reproduction complexity heredity homeostasis*

Cell

the basic unit of life

Homeostasis

the maintenance of a constant internal body environment by an organism's body

Scientists distinguish whether an entity is living or nonliving by describing the ___ of life.

1. characteristics* 2. value 3. length 4. quality

It is difficult to determine a definition for life that is suitable for all situations. Instead of defining life, biologists have decided to ___.

1. describe the characteristics of life* 2. determine if something is living or non-living based on its complexity 3. qualify life based on whether something can move or not 4. determine something is living if it responds to outside stimuli

If something exhibits all of the characteristics of life, it is considered to be ___.

1. inanimate 2. non-living 3. alive* 4. dead

The ability to obtain nutrients, take in oxygen, and transform these items to energy and cellular components is called ___.

1. life 2. metabolism* 3. a life cycle 4. continuation

Which of the following is not a characteristic of life?

1. the ability to respond to the environment or stimuli 2. the ability to move* 3. the ability to reproduce 4. the ability to obtain and use energy

If a rock disintegrates by chemical weathering into small grains of similar composition, would this be considered reproduction?

1. yes 2. no*