Lecture I: Characteristics of Living Organisms & Levels of Biological Organization

Question 1

7 Characteristics of Living organisms

Answer 1

Have organized structure made up of organic molecules (molecules of life).
Are made up of one or more cells.
Grow, develop and reproduce.
Need energy to survive.
Respond to stimuli.
Maintain homeostasis.
Have the ability to evolve over generations.

Question 2

What are the 4 organic molecules?

Answer 2

Protein, Carbs, Lipids, Nucleic Acids

Question 3

What is the difference between growing and developing?

Answer 3

Growing: increase in size and cell number
Develop: Change in form (transformation)

Question 4

Two types of reproduction?

Answer 4

Sexual/Asexual

Question 5

What is energy used for?

Answer 5

Energy is taken in by living organisms to fuel metabolic reactions.

Question 6

What is Metabolism?

Answer 6

The sum of all chemical reactions within living cells. It allows to perform all the chemical reactions that allow to do the necessary functions

Question 7

What are the two types of stimuli?

Answer 7

Internal and external stimuli, which are both responses to changes in the environment, either internal (pH of blood) or external (predators).

Question 8

Define homeostasis

Answer 8

The ability to maintain a specific internal environment.

Question 9

What is an adaptation?

Answer 9

Traits that allow them to survive better in their environment will become more prevalent over time. These are called adaptations.

Question 10

What are the 8 levels of Oragnization?

Answer 10

Atoms
Molecules
Organelles
Cells
Tissues
Organs
Organ systems
Multicellular Organism

Question 11

What is an organelle?

Answer 11

Organelles are the different distinct structures found within cells.

Each organelle has a specialized function.

Organelles are made up of molecules.
Examples include the nucleus and the mitochondrion

Question 12

What is a cell?

Answer 12

The smallest level of organization that can sustain life

Question 13

What are the 4 characteristics shared by all cells?

Answer 13

All cells are surrounded by a membrane.

All cells have internal mass (cytoplasm).

All cells contain genetic material (DNA).

All cells have ribosomes ( required to make proteins).

Question 14

Characterize the Procaryotic cell.

Answer 14

Small in size 1 -10 µm

DNA not enclosed within it’s own membrane. DNA molecule is Circular in shape.

Lack membrane bound organelles

Have ribosomes (for protein synthesis)

Cytoplasm fills the cell.

Question 15

Characterize the Eukaryotic cell

Answer 15

Larger in size 10 -100 µm

DNA is enclosed within it’s own membrane = nucleus
DNA molecules are linear strands.

Contain many membrane bound organelles each with specialized functions and Ribosomes.

Cytoplasm fills most of the cell, but is not found within the nucleus.

Question 16

Define Tissues

Answer 16

A group of similar cells within an intercellular matrix (substance surrounding the cells) specialized to perform a specific function are called tissues.
e.g. Bone, muscle, nerve, etc…

Question 17

Define Organs

Answer 17

Organs are made up of several different types of tissues, but they work together to perform the same function.

Question 18

Define Organ Systems

Answer 18

Organs that work together to perform a particular function.

Question 19

Define Living Organism

Answer 19

Independent living unit, composed of molecules, organelles, cells, tissues, organs and systems

Question 20

Define Population

Answer 20

A group of individuals of the same species (unicellular or multicellular) living in the same area.

Question 21

Define Community

Answer 21

Community ecology studies the interactions that occur between different species within a given area.

e.g. predator/prey

Question 22

Ecosystem

Answer 22

All of the living organisms in a given area (the community or biotic component)

Plus,

The physical environment (abiotic component) they interact with.

Question 23

Biosphere

Answer 23

The entire portion of Earth inhabited by living organisms