Biology and the Characteristics of Life

Aim: How do living things carry out metabolic activities?

• Do now: Answer the following question:

• How do you know if an organism

• is living?

• Vocabulary: life functions, homeostasis, develop, reproduction

What is Biology?

the study of

living things.

Living things are diverse.

Largest animal is the blue whale.

• 33 yards in length (about 1/3 football field)

• weigh up to 130 metric tons (= 30 elephants)

Largest plant is the

giant sequoia tree. 

Over 100 yards tall.

Smallest living things are bacteria.

• Size – 10-6 meters

• 100 times smaller than a dot or period.

What makes a living thing “alive”?

Characteristics of living things.

• All living things are made of cells.Unicellular = 1 celled (ex. Bacteria, yeast)

Multicelled = many cells (Frogs, mice, humans)

2) Living things maintain

homeostasis.…a stable internal

environment.

EX: People sweat when

they need to cool their

bodies and shiver to

warm them.

Living things reproduce and use DNA, the genetic material, to carry heritable information.

3) Reproduce

Asexual reproduction: only one organism, offspring are exactly like parent.

(ex: Unicellular organisms divide by binary fission.)

Two types of reproduction: asexual and sexual.

Sexual Reproduction: two organisms. Fertilization of egg cell by a sperm cell. Offspring will be a “mixture” of the parents.

4) Living things have organization

subatomic particles --> atoms --> molecules --> organic molecules ---> cells --> tissues --> organs

                                                                                                                                                                  

                                      

5) Living things grow & developGrowth and development occur through

cell division.

6) Living things obtain energy

Organisms can obtain energy in 2 main ways:a) Autotrophs – make their own food (ex: plants & algae)

b) Heterotrophs – eat other organisms (ex: lions & tigers &

bears)

7. Living things respond to stimuli

They may move toward an external stimulus or away from it.

Movement is part of the behavior of a living thing.

8. Living Things Evolve

• Groups Of Organisms (Not Individuals) change over time in order to survive within changing environments.

• Fossil records show changes in groups of organisms

QUIZ -Living things share 8

characteristics. Which two are missing from this list?

• Grow and develop

• Obtain energy

• Respond to stimuli

• Maintain homeostasis

• Reproduce

• Have organization