Chpt. 1: The Characteristics of Life

abiotic

(non-living) physical rather than biological; not derived from living organisms.

The place of humans among living organisms

-vertebrates -mammals -Kingdom: Animals -Primate

All living organisms share these basic characteristics

1) they are organized 2)acquire materials and energy 3)are homeostatic 4)respond to stimuli 5) reproduce and have the potential for growth 6)have an evolutionary history

DNA

A complex molecule containing the genetic information that makes up the chromosomes.

natural selection

A natural process resulting in the evolution of organisms best adapted (adaptation) to the environment.

homeostasis

A tendency to maintain a balanced or constant internal state. What's on the outside can't be controlled (external stimuli), so the inside is controlled. -maintain constant internal temperature

A human's culture describes the products and activities that are passed on from one generation to the next outside of direct biological inheritance. Humans are the only organisms that have language that allows the communication of information and experiences symbolically. As part of their culture, humans pass on their beliefs, values, and skills to the next generation. Some of these skills include tool use, including how to hunt in the wild or use computers.

Humans and other organisms are an integral part of the biosphere, a living network that spans from the surface of the Earth into the atmosphere. This living network provides many services for human beings. For instance, microorganisms aid humans in breaking down, or decomposing wastes. Though we are a part of our living world, human beings modify this world greatly, sometimes to the Earth's detriment. The culture of humans has led us to separate ourselves from the living world in many ways. Because we disconnect ourselves from the natural world, we often exploit such things as land and water with little consideration for the impact we have on biodiversity.

Life requires materials and energy

Humans, like all living organisms, cannot maintain their organization or carry on life's activities without an outside source of materials and energy.

evolution

The gradual change in a species over time

The smallest units of an element are atoms; when they combine, they form molecules. Various molecules group together to eventually form cells, or the basic units of all living things. Some organisms, such as bacteria, are unicellular, while others, such as humans, are multicellular. Among multicellular organisms such as humans, groups of cells with similar functions make up tissues. Groups of tissues combine to form organs, which work together to form organ systems, which function together to accomplish a common purpose. Humans and trees are examples of organisms, or collections of these organ systems.

The process by which a population changes over time is referred to as evolution. Within populations, variation exists so that some members are more likely to capture resources. These members are more likely to reproduce, passing on their traits to future offspring. In this manner, these traits increase in frequency in future generations. This drives the process of evolution.

On the basis of one or more observations of natural phenomena, a testable explanation called a hypothesis is formed. A hypothesis is tested with observation and/or experiments. Data, which results from experiments, either support or do not support the hypothesis. The data help scientists to form conclusions, some of which may encourage them to redesign their experiments or formulate a new hypothesis.

The scientific method begins with the observation of phenomena or natural events. Scientists use inductive reasoning to combine isolated facts into a plausible explanation, or hypothesis. Scientists use deductive reasoning to design an experiment to test their hypothesis. Scientists develop a good experimental design that contains both a(n) experimental group in which the experimental variable is altered, and a control group in which the experimental variable is not altered. Occasionally, scientists are forced to use a model to represent the actual phenomenon, usually for ethical, financial, or logistical limitations. The results of an experiment are called data and must be analyzed in order for a conclusion to be reached.

Explain the relationship between adaptations and evolutionary change.

Variations arise (usually due to random genetic mutation) that sometimes provide a survival advantage for some individuals. Individuals with this advantage tend to reproduce more, which causes the variation to become more common in the population.

ecosystem

a community plus the physical environment

tissue

a group of cells with a common structure and function

species

a group of similar, interbreeding organisms

metabolism

all of the chemical reactions in a cell

organism

an individual; complex individuals contain organ systems

The branch of science that is the study of living creatures and their environments is called

biology.

organ system

composed of several organs working together

organ

composed of tissues functioning together for a specific task

community

interacting populations in a particular area

Biology is the study of

living organisms and the environments they live in

biotic

living things

population

organisms of the same species in a particular area

How many cells are in the human body?

over 100 trillion

The ultimate source of energy for the majority of life on earth is the sun. Plants, algae, and some bacteria are able to harvest the energy of the sun and convert it to chemical energy via the process called

photosynthesis

biosphere

regions of the Earth's crust, waters, and atmosphere inhabited by living things

atom

smallest unit of an element composed of electrons, protons, and neutrons

energy

the capacity to do work

cell

the structural and functional unit of all living things

molecule

union of two or more atoms of the same or different elements