1.1 the study of life earth is home to an incredible diversity of life. diversity – differences...

1.1 The Study of Life

Earth is home to an incredible diversity of life.

• Diversity – differences• The Biosphere includes all living things and all the places

they are found.


The biosphere includes many environments.– land


– saltwater and freshwater environments

– portions of the atmosphere


– Biodiversity generally increases from the poles to the equator.

– Biodiversity is greater in areas with consistently warm temperatures.

• Biodiversity is the variety of life.

Biodiversity is greater closer to the equator.


– Members of a species can interbreed to reproduce. – There are about 2 million different living species that

have been identified.

• A species is one particular type of living thing.


An organism is any individual living thing.


1. All are made of one or more cells.

All organisms share certain characteristics.•Characteristics of Life:


2. All need energy for metabolism. - Sum of all chemical processes in a body

3. All respond to their environment.– Stimuli Environmental Factors (light, temperature,

touch)– Response Reaction of the organism to the stimulus

4. All Reproduce and Develop– All have DNA that they pass on to offspring.


All levels of life have systems of related parts.

• A system is an organized group of parts that interact to form a whole.– A cell is a system of chemicals and processes.– A body system includes organs that interact.

• An ecosystem includes living and nonliving things that interact in a physical environment.

1.2


• Biologists study many different systems.

1.2


Structure and function are related in biology.

• Structure determines function.– Proteins with different structures perform different

functions.– Different species have different anatomical structures

with different functions.

1.2


Organisms must maintain homeostasis to survive in diverse environments.

• Homeostasis is the maintenance of constant internal conditions in an organism.

• Cells function best in limited conditions– Temperature, blood sugar, acidity, etc.

1.2


• Homeostasis is usually maintained through negative feedback.– Negative feedback system – a change in a system

causes a response that returns the system to its original state.

1.2


• Behaviors and adaptations can help maintain homeostasis.

1.2


Evolution explains the unity and diversity of life.

• Evolution is the change in living things over time.– The genetic makeup of a population of a species

changes.– Evolution can occur through natural selection of

adaptations.– Adaptations are beneficial inherited traits that are

passed to future generations.

1.2


• Natural selection of genetic traits can lead to genetic diversity which is responsible for the diversity of life.

• Organisms have similar cell structure and similar chemical processes

1.2


Maintaining safety

• Safety Symbol – a symbol that warns you about a danger that may exist from chemicals, electricity, heat, or procedures you will use

1.3


Like all science, biology is a process of inquiry.Scientists make careful and systematic observations.• Observation – using our senses to study the world.

Scientists test their hypotheses and analyze their data.

Scientists form a hypothesis as a possible answer to a question. •hypothesis must be specific and testable

Scientists record observations as data.

1. Qualitative Data – descriptions

2. Quantitative Data – measurements• (mass, volume, Temperature)

1.3


Independent variable condition that is changed by scientists

– Only 1 independent variable is tested in an experiment

– Constants are conditions that are kept the same.

Dependent variable are observed and measured during an experiment.

Control Group – Everything is kept constant (normal conditions)Experimental Group – Independent variable is changed

1.3


Analyzing Data• Statistics and Mathematics• 2 possible outcomes

• Nonsignificant – data shows no effect or so small of an effect it could of happened by chance

•Hypothesis is rejected often leads to a new hypothesis

• Statistically significant – effect is likely not due to chance

1.3


• A theory is supported by a wide range of scientific evidence.

• Theories can change based on new evidence.

1.3


Imaging technologies provide new views of life.

• A microscope provides an enlarged image of an object.

– light microscopes (LM) – light passes through specimen

1.4


– scanning electron microscopes (SEM) – 3 D image of the surface



– light microscopes (LM)

1.4


– transmission electron microscopes (TEM)

– scanning electron microscopes (SEM)



– light microscopes (LM)

Electron microscopes • higher magnification•Cannot be used to study living organisms

1.4


• Imaging technology is used in medicine.

– X-ray images X-ray images – look at skeleton

1.4


– magnetic resonance imaging (MRI) – strong magnetic field

- Can view soft tissue


– X-ray images

1.4


– functional MRI (fMRI)- Shows where activity is

taking place

– magnetic resonance imaging (MRI)


– X-ray images

1.4


• Computer models are used to study systems that cannot be studied directly.– heart attacks– effect of medicines on the

human body– movement of water molecules

into and out of a cell– spread of a disease through a

population• Computer models are used when

experiments are not safe, ethical, or practical.

Normal heartbeat

Heart attack

1.4


The tools of molecular genetics give rise to new biological studies.

• A gene is a segment of DNA that stores genetic information.

1.4


• Through our understanding of DNA, we can study genetics on a molecular level.

– molecular genetics – study and manipulation of DNA

– Genomics – study and comparison of genomes both within a species and across species

1.4


Your health and the health of the environment depend on your knowledge of biology.

• food allergies• potential effects of obesity

1.5


– cancer

• Knowledge of biology helps you understand: your health

– effects of alcohol, tobacco, and other drugs

1.5


• Knowledge of biology can help you understand: environmental issues– interactions in ecosystems

– Animal deformities– chemicals in water,

radiation, infection

– pollution

1.5


– Medicine, agriculture, forensics

1.5

Biotechnology is the use and application of living things and biological processes.


• Transgenic – altered copies of an organisms own genes

– crops - (genetically modified) increase nutrients, yield of plants and resistance to insects

– bacteria – make human insulin (diabetes)– sheep/cows – human antibodies and proteins

1.5


• Questions are raised about the use of biotechnology.

– spread of undesirable genes– decrease in biodiversity– ethical considerations

– Who should have access? (insurance companies?)– How should information be used? (reveal child might

have genetic disorder or choose characteristics of children?)

– long term effects

1.5


• There are still many questions to answer in biology.

– How are memories stored in the brain?

1.5


– How are memories stored in the brain?

– Does life exist on planets other than Earth?

– How do viruses mutate?

1.5

1.1 the study of life earth is home to an incredible diversity of life. diversity – differences...

Documents

study of life homeostasis

study of life biodiversity

study of life structure

study of life organisms

study of life evolution

study of life saltwater

study of life earth

study of life behaviors