Characteristics of Life

Science vs Psuedoscience◦Psuedo = ????????

Science vs Psuedoscience◦Psuedo = false/fake

Science is either :◦Physical or Biological

Physical Science is: remember last year◦ Non-living◦ Earth Science

Meteorology – Weather Oceanography – Oceans Geology – Rocks and Minerals Astronomy – Stars and Planets

◦ Chemistry – Make-up of matter and it’s changes◦ Physics – Study of Energy: heat, light, electrical,

mechanical, and nuclear

Biological Science is:◦ Living – Biology is the study of life◦ Botany

Plants

◦ Zoology Animals

◦ Environmental: Botany and Zoology◦ Anatomy: Zoology◦ Organism – an individual capable of life

processes

The Goal of Science is:◦The process of gaining new knowledge

about the world (nature) living and non-living through data collection

◦ Data- information gathered from observations 1. Quantitative

-numbers-count (1,2,3, etc…)-measure (1g, 2 cups)

2. Qualitative-descriptive characteristics

the dog looks old

A. Variable- one factor being tested ◦ 1. Manipulated Variable (independent)

-deliberately changed◦ 2. Responding Variable (dependent)

-observed changes in response to manipulated variable

B. Control-experiment w/out variable◦ It’s the part you DON’T change in experiment

Designing an Experiment SCIENTIFIC METHOD

◦ State the problem◦ Form a hypothesis

If……….and ……..then◦ Set up experiment◦ Record data◦ Analyze results◦ Draw a conclusion

The true nature of science and experimentation lies in the hypothesis

Three parts IF…. Problem part of experiment CONTROL AND…contains INDEPENDENT

maninipulated variable THEN…. Contains the DEPENDENT

responding variable

people made observations and said that some living things could suddenly appear:◦ -Maggots on meat (no refrigerators then)◦ -Mice on grain◦ -Beetles on cow dung

Thought: live arose (came) from nonliving ◦ -maggots arose from meat◦ -beetles arose from dung

Spontaneous Generation- idea that life could arise from nonliving matter

 

1668- Redi◦-propose a different hypothesis for why maggots appear on meat Question: Do flies produce maggots?

◦ The idea that life only comes from other life◦ Disproved spontaneous generation by putting meat

into jars

Published result in a book that other scientist read.

Redi’s Experiment:◦ Some jars were covered with a mesh cloth◦ Others were left open◦ Several days later maggots were on the meat in

open jars, no maggots were on the covered meat

Anton van Leeuwenhoek◦-discovered tiny moving objects in pond water, rainwater, and dust

◦-objects “alive” -called them animolecules or “tiny animals”

-made drawings -shared with other scientists

Needham◦-challenged Redi’s work◦-Remember: Redi= no spontaneous generation

-Needham = spontaneous generation could occur under the right conditions

-sealed bottle of gravy and heated it◦-claimed heat killed any living organisms

◦-waited a few days◦-observed tiny organisms (microorganisms)

-conclusion: organisms could have only come from juice of gravy

-Thought Needham didn’t heat gravy long enough- improved experiment◦ -2 bottles of gravy◦ -both boiled◦ -1 open, 1 sealed◦ -waited a few days

Conclusions:◦ -open bottle= many microorganisms◦ -closed bottle = none

life only comes from life

Pasteur (mid 1800’s)◦ Repeated past experiments

Designed a curved (swan neck) flask Flask remained open but air could not make it

through the neck in to the flask Showed as long as broth was protected from

microorganisms, it remained free of living things◦ Year after experiment began

Broke flask Organisms grew

Observations use senses to gather information

Inference is logical interpretation (not always fact) based on prior knowledge

Theory-most logical explanation for an event in nature◦ -time-tested◦ -dependable prediction

If a theory survives time and experimentation it becomes a:

Scientific Law- summarizes facts◦ -does NOT explain◦ -states what always happens under given

circumstances  **Both Laws and Theories are tentative

◦ -they may change as new information is provided

Nine (9) Characteristics all living things have in common

FRED H GARC

FRED◦F – Use and need Food

◦R – Must be capable of Reproduction

◦E – Must be able to transfer Energy

◦D – Develop and Grow Undergo a series of stages to reach maturity Infant – Toddler – Young Adult – Adult And an increase in living material

H◦H – Homeostasis

Steady internal state H+

Blood Pressure Respiration Body Temperature Ect.

GARC◦G – Genetic code Based on universal genetic code

◦A – Adapt to change Structural – wings, arms, ect. Physiological – internal body processes Behavioral – innate, learned

◦R – Respond to stimuli

◦C – Made of at least one (1) Cell

1. molecules2. cells3. groups of

cells (tissues, organs & organ systems)

4. organisms

7. Populations

8. Community

8. Ecosystems

8. Biosphere

Biotic◦ Living factors

Abiotic◦ Non-living factors

Adaptation◦ A feature that enable survival

Species ◦ A group of similar looking organisms that can

breed and produce offspring Evolution

◦ A gradual change in a species over time

Characteristics of Life