BIO 103 Ch.1

What is the definiton of biology?

The study of life

Living things and non living things

are all composed of the same chemical elements. Also obey the same physical and chemical laws that govern everything in the universe.

What did Carl Sagan mean when he said we are all made of star stuff?

The elements that made us up probably made up other people and animals years ago. The atoms that make up one being will be used to make another in the future. (Matter cannot be created nor destroyed)

What are the characteristics of life?

1. Organized from the atom to the biosphere

2. Use materials and energy from the environment (sun?)

3. Maintain a relatively constant internal environment (homeostasis)

4. Respond to internal and external stimuli

5. Reproduce and grow

6. Have the ability to change over time

What is homeostasis?

A constant state of sameness

The cell

is the basic unit of structure and function of all living things (of life, unicellular or multicellular.)

Levels of biological organization

Atoms > Cells > Tissue > Organ > Organ system > Organism > Population > Community > Ecosystem > Biosphere

Atom

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

Molecule

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

Cell

The structural and functional unit of all living things

Tissue

A group of cells with a common structure and function

Organ

Composed of tissues functioning together for a specific task

Organ system

Composed of several organs working together

Organism

An individual; complex individuals that contain organ systems

Population

Organisms of the same species in a particular area

Community

Interacting populations in a particular area

Ecosystem

A community plus the physical enviornment

Biosphere

Regions of the earths crust, water, and atmosphere inhabited by living things

Emergent properties

As things become more complex they have unique properties that arise

What is an example of emergent properties?

A forest instead of just a tree

A whole tree with lots of limbs and a canopy, that could be a nesting area for birds, and a breeding ground for insects, that could be a place where fruits are grown.

There are other things that can happen there as a result of there unique complexity

What is the second characteristic of life?

Life requires materials (Matter) and energy.

What is energy?

the capacity to do work.

What is metabolism?

all the chemical reactions that occur in a cell.

What do all living organisms require?

Energy

Why is energy required by living organisms?

Energy is required to maintain organization and conduct life-sustaining processes, such as chemical reactions.

What is the ultimate source of energy for nearly all life on Earth?

The sun

What organisms can capture solar energy and perform photosynthesis?

Plants, algae, and some other organisms.

What is photosynthesis?

Photosynthesis is the process that converts solar energy into the chemical energy of carbohydrates.

What is cellular respiration?

Cellular respiration is the process cells use to break down carbohydrates and other molecules to release chemical energy that can be used to power cellular activities.

What is the main purpose of cellular respiration?

To release energy from food molecules and convert it into a usable form of energy for the cell, primarily ATP.

How are photosynthesis and cellular respiration related?

Photosynthesis stores solar energy in carbohydrates, while cellular respiration releases energy from those carbohydrates for cells to use.

What is the third characteristic of life?

Living things maintain homeostasis.

What is homeostasis?

Homeostasis is the maintenance of internal conditions within certain boundaries.

Why is it important for organisms to maintain homeostasis?

It is important for an organism to maintain a state of biological balance.

What do feedback systems do?

Feedback systems monitor internal conditions and make adjustments to maintain homeostasis.

What is a set point in homeostasis?

A set point is the ideal or normal value that an organism tries to maintain for an internal condition, such as body temperature.

What happens when an organism's internal condition moves away from its set point?

A: A feedback system detects the change and makes adjustments to bring the condition back toward the set point.

What are the main parts of a feedback system shown in the diagram?

A receptor, control center, and effector.

What does a receptor do in a feedback system?

A receptor detects a change or imbalance in an internal condition.

What does the control center do in a feedback system?

The control center receives information from the receptor and determines the appropriate response.

What does an effector do in a feedback system?

An effector carries out the response to the change.

What is an example of the body maintaining homeostasis when it gets too hot?

The body can use sweating and vasodilation to help lower body temperature.

What is an example of the body maintaining homeostasis when it gets too cold?

The body can use shivering and vasoconstriction to help increase or conserve body heat.

What is a stimulus?

A stimulus is a change in the environment that causes an organism to respond.

How do living things respond to stimuli?

Living things interact with their environment and respond to changes in the environment.

What can the ability to respond to stimuli often produce?

Movement.

(WATCH LECTURE VIDEO TO UNDERSTAND. Slide 5)

What is an example of animals responding to environmental changes?

Animals may change their behavior, movement, or population in response to changes in their environment.

(WATCH LECTURE VIDEO TO UNDERSTAND. Slide 5)

What does the graph of snowshoe hares and lynx demonstrate?

A: It demonstrates how living organisms interact with and respond to changes in their environment, such as changes in predator and prey populations.

What larger biological concept is this response to the environment a basis for?

A: The ecosystem concept.

What are ecosystems characterized by?

Ecosystems are characterized by chemical cycling and energy flow.

What happens to chemicals when an organism dies?

Chemicals are not used up when organisms die. They can be returned to the environment and reused.

How do chemicals move through an ecosystem?

Chemicals move from one population to another in a food chain.

In what order can chemicals move through a food chain?

Chemicals can move from producers → consumers → decomposers.

What are matter cycles?

Matter cycles are processes in which chemicals and nutrients are recycled through ecosystems rather than being used up.

What happens to chemicals after death and decomposition?

Chemicals are returned to living plants, allowing them to be reused.

What is the difference between chemical cycling and energy flow?

Chemicals cycle through an ecosystem and are reused, while energy flows through the ecosystem and is eventually lost as heat.

Where does the energy that flows through most ecosystems come from?

The Sun.

How does energy flow through a food chain?

Energy from the Sun flows through plants and other members of the food chain as one population feeds on another.

Why must there be a constant input of solar energy into an ecosystem?

Because energy flows through the ecosystem and is eventually lost as heat, so a constant input of solar energy is needed.

What role do producers play in energy flow?

Producers, such as plants, capture solar energy and make it available to the rest of the food chain.

What role do consumers play in an ecosystem?

Consumers obtain energy and chemicals by feeding on other organisms.

What role do decomposers play in an ecosystem?

Decomposers break down dead organisms and return chemicals to the ecosystem.

What is shown by the carbon cycle in the image?

The carbon cycle shows how carbon moves between the atmosphere and living organisms through processes such as photosynthesis, respiration, and decomposition.

What is photosynthesis's role in the carbon cycle?

Photosynthesis removes CO₂ from the atmosphere and incorporates carbon into plants.

What happens to energy as it moves through an ecosystem?

Some energy is transferred between organisms, but energy is ultimately released as heat.

What are the two major characteristics of ecosystems?

Chemical cycling and energy flow.

What happens to matter in an ecosystem?

Matter cycles and is reused.

What happens to energy in an ecosystem?

Energy flows through the ecosystem and is eventually lost as heat.

What is the ultimate source of energy for most ecosystems?

The Sun.

What is the fourth characteristic of living things?

Living things reproduce and develop.

Why must all living organisms reproduce?

All living organisms must reproduce to maintain a population.

Is reproduction the same in all organisms?

No. The manner of reproduction varies among different organisms.

What do organisms pass on when they reproduce?

They pass on copies of their genetic information (genes) to the next generation.

What are genes?

Genes are units of genetic information that determine the characteristics of an organism.

What do genes determine?

Genes determine the characteristics or traits of an organism.

What are genes composed of?

Genes are composed of DNA.

What does DNA stand for?

Deoxyribonucleic acid.

Why is genetic information important during reproduction?

It allows organisms to pass characteristics to the next generation.

What is the fifth characteristic of living things?

Living things have adaptations.

What is an adaptation?

An adaptation is any modification that makes an organism better able to function in a particular environment.

Why does the diversity of life exist?

The diversity of life exists because, over long periods of time, organisms respond to changing environments by developing new adaptations.

How do organisms respond to changing environments over long periods of time?

They develop new adaptations that help them function better in their environment.

What is evolution?

Evolution is the change in a population of organisms over time to become more suited to the environment.

How are adaptation and evolution related?

Adaptations help organisms become better suited to their environment, while evolution describes changes in populations over time that can result in organisms becoming better suited to their environment.

What does "survival of the fittest" mean?

It refers to the idea that organisms better suited to their environment are more likely to survive and reproduce.

What are the two characteristics of life covered in these slides?

Living things reproduce and develop, and living things have adaptations.

What are genes made of?

DNA.

What do genes determine?

The characteristics of an organism.

What is an adaptation?

A modification that makes an organism better able to function in a particular environment.

What is evolution?

Change in a population over time to become more suited to the environment.

What generates biodiversity?

Evolution generates biodiversity.

What is natural selection?

Natural selection is the process in which traits that enhance survival and reproduction are passed on more frequently to future generations.

Who first proposed the theory of natural selection?

Charles Darwin.

What happens to traits that improve survival and reproduction?

They are passed on more frequently to future generations than traits that do not.

What does 'descent with modification' mean?

It means that traits are inherited across generations but populations change over time.

What is adaptation?

Adaptation is the process in which, over time, traits that lead to better reproductive success become more prevalent in a population.

What happens to a beneficial trait over many generations?

It tends to become more common in the population because organisms with the trait have greater reproductive success.

Does adaptation happen quickly?

No. Adaptation generally takes place over many generations.

Why does adaptation take a long time?

Because beneficial traits must be passed from generation to generation and gradually become more common in the population.

Does an individual organism adapt through natural selection, or does a population adapt?

A population adapts over generations.