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What is Biology?

The study of living organisms and the environment they live in.


Characteristics of Organisms

They are organized, acquire material an energy, are homeostasis.


How is life organized?

The hierarchy is at the very base of the organizations, atom's join together to form molecules, which in turn make a cell.


What are Cells?

A cell is the smallest structural and functional unit og an organism.


What is nervous tissue?

A tissue is a group of similar cells that perform a particular function. Nervous tissue is composed of millions of nerve cells that transmit signals to all parts of the body.


What is an organ?

An organ is made up of several different tissues, each one belongs to an organ system. Both work together to accomplish a common purpose. The brain works with the spinal cord to send commands to other parts of the body through nerve organisms.


What are types of nerve organisms?

Trees and Humans are a collection of organ systems.


What is a species?

A group of inter-breeding organisms in a particular area belonging to a population. For example: a grassland may have a population of zebras, acacia trees and humans, the interacting populations of the grasslands make up a community.


What does the community do?

The community of the population interacts with the physical environment to form an ecosystem. Earths ecosystem makes up the biosphere.


What is biological organization?

Life is connected from the atomic level to the biosphere. The cell is the basic unit of life, and it comprises molecules and atoms. The sum of all life on the planet is called the biosphere.


How many cells are in the human body?

There is estimated to be over 100 trillion cells in the human body.


What does food provide to life?

Food provides nutrient molecules, which are used as building blocks for energy. Energy helps maintain the organization of the cell and the organism itself. Some nutrient molecules are broken down completely to provide energy necessary to covert other nutrient molecules into the parts and products of cells.


What is the source of energy for life?

The source of energy for the majority of life on earth is the sun. Plants, Algae and other bacteria's are able to harvest the energy of the sun and concert it to chemical energy by a process called Photosynthesis.


How do organisms maintain internal envrionment?

In order for cells to function correctly environmental conditions must be kept in strict operating limits. By doing this, metabolic activities of the cells function is maintaining homeostasis.


How does body temperature effect homeostasis?

Human body temperature fluctuates between 36.5-37.5 degrees during the day, lowest body temperatures occur between 2am-4am, the highest occurs between 6pm-10pm. Activity in the body can cause the temperature to rise but inactivity can cause it to decline.


What is the purpose of homeostasis?

Homeostasis is when the metabolism in our body maintains a relatively constant body temperature. Our body systems, the cardiovascular system and nervous system work together to maintain a constant temperature.

The bodies ability to maintain a normal temperature is also dependent on external temperature as we can become hot and cold.


Is it possible to maintain homeostasis without the bodies ability to respond to stimuli, both external and internal environments?

No, it would be impossible.
The response to external stimuli is more apparent because it involves movement, like when we remove our hand from a hot stove. Our sensory receptors detect a change in he internal environment and then the central nervous system brings an appropriate response.

All life responds to external stimuli, often by moving towards or away from stimulus.


How does life respond to external stimuli?

Life responds by moving towards or away from the stimuli, such as food. Organisms use a variety of mechanisms to move, but movement in humans and other animals in dependent on their nervous and musculoskeletal systems. The leaves of plants track the passage of the sun during the day, when a houseplant is placed near a window stems bend and face towards the sun. The movement of an animal whether elf directed or in response to a stimulus constitutes a large of of its behavior. Some behaviors help us to acquire food and reproduce.


How do organisms reproduce?

Organisms pass on their genetic information t the next generation. Following the fertilization of an egg by a sperm cell, the resulting zygote undergoes a rapid period of growth and development.


How do humans reproduce?

In humans, growth occurs as the fertilized egg develops into a fetus, Growth is recognized by an increase in size and often in the number of cells, which is part of the development.


What is development?

In multicellular organisms, development is used to indicate all the changes that occur from the time the egg is fertilized until death. This includes childhood, adolescence and adulthood.


What is DNA (deoxyribonucleicacid) ?

DNA is the genetic information of all life, it contains the hereditary information that directs not only the structure of each cell but also its function. The information in DNA is contained within genes, short sequences of hereditary material that specify the instructions for a specific trait.


What stage occurs prior to reproduction?

Replication stage, DNA is replicated so an exact copy of each gene may be passed to the offspring. When human reproduce a sperm carries genes contributed by a male into the egg, which contains genes contributed by a female. The genes direct both growth and development so that the organism will eventually resemble the parents.


What is mutation?

Mutation is a minor variation in genes which can cause an organism to be better suited for its environment. These mutations are the basis of evolutionary change.


What is evolution?

Evolution is the process by which a population changes overtime.


What is natural selection?

natural selection is a mechanism by which evolution occurs, when a new variation arises that allows certain members of a population to capture more resources, these memes tend to survive and have more offspring than the other, unchanged members.


What is adaption to an environment?

Adaption is when each successive generation will include more members with a new variation.