Transcript Biology and You, Section 1x




Biology is the study of life.
Individual living things = organisms
Scientists use these life properties to distinguish
between life and non-life:
-Organisms have cells
-Organisms get and use energy
-Organisms maintain a stable internal
environment= homeostasis
-Organisms reproduce
-Organisms respond/adjust to the environment
-Organisms pass on traits to offspring = heredity
-Organisms grow and develop








The science of biology has seven recurring
themes:
Cellular structure and function
Reproduction
Metabolism
Homeostasis
Heredity
Evolution
Interdependence


The smallest units of life
Some organisms only have 1=unicellular
Examples include bacteria, paramecium
Some organisms have more than 1=
multicellular
Examples include rosebush, human being


The process by which organisms make more
of their own kind
Insures continuation of the species




All living things must be able to obtain
energy and use it for cell processes
Energy is needed to grow, move, and process
information
The sun is the ultimate source of energy
Green things, such as some bacteria, algae,
and green plants change light energy into
food molecules during photosynthesis.
The maintenance of a stable, internal
environment
 Homeostasis is maintained despite the
external environment.
 Examples of mechanisms include
Body temperature, respiration rates, and
heart rate







Living things pass traits on to young through
genes
Genes are the basic unit of heredity
Genes are coded in DNA
Heredity is the passing of traits from parents
to offspring
A change in the DNA of an organism is called
a mutation—if change occurs in the sex cells,
a new trait can be passed on
Sickle Cell Anemia is an example



Change in the inherited characteristics of a
species over time is called evolution
A species is a grouping of organisms that can
reproduce offspring that can also reproduce
Charles Darwin, a British naturalist described
a mechanism for evolution called natural
selection




A group of living things that share the same
space is called a community
The organisms in a community live and
interact with each other
Ecology is the branch of Biology that studies
these interactions
Living things also interact with the nonliving
environment








Modern biology is concerned with solving some
real world problems
Preserving the environment
Improving the food supply
Understanding the human genome
Fast food french fries are a great example!
Potatoes that are not suitable can be used to feed
cattle
Leftover potato bits provide methane gas
French fry soaking water, rich in nutrients, can be
used to water and fertilize agricultural crops




A new process, genetically engineered food
crops, gives foods new improvements
Food crops can be made to be poisonous to
insect pests
Food crops can be made resistant to
herbicides
Food crops can be changed to have improved
nutrient content


In April, 2003 (ahead of schedule) scientists
cracked the human DNA code and completely
sequenced the human genome
A genome is all the genetic information an
organism has coded in its DNA





AIDS and Cancer are big areas of research
AIDS is caused by a virus that attacks the
immune system
Cancer is caused by a breakdown in the
mechanism that controls cell division
New diseases, such as West Nile Virus and
Mad Cow Disease cause need for more
research
Gene therapy may help cure diseases such as
cystic fibrosis