Biology: Key Concepts, Characteristics, and Scientific Methods

What is biology?

The study of life

What are the 5 characteristics of life?

1. Organization

2. Energy use and Metabolism

3. Homeostasis

4. Reproduction, growth, and development

5. Responsiveness

What is Homeostasis

an organism maintains internal consistency.

Examples of homeostasis

Body temperature, blood, pH, Ion salts

asexual reproduction

Results in genetic clones (identical)

sexual reproduction

Genetic material from 2 individuals combined to form a combined genetic material

What are the 4 steps of the scientific method?

observation, hypothesis, experiment, conclusion

What does the experimental method involve?

Independent and dependent variables

What is the independent variable?

set by the experimenter (x- axis)

What is a dependent variable?

variable that is measured (y-axis)

What is Individual

One organism

What is a population?

a group of individuals of the same species living in the same area at the same time

What is Community

All the different populations that live together in an area

Ecosystem

a community of living organisms interacting with their physical environment, which includes both biotic and abiotic factors.

Examples of an ecosystem

Water, soil, CO2, O2

What is the biosphere?

The overlapping of all ecosystems, encompassing all living organisms and their interactions with the environment, including land, water, and atmosphere.

What are Primary Producers

Can photosynthesize and self feed.

What are decomposers?

organism that breaks down dead plant and animal materials

Examples of decomposers

earthworms, fungi, insects

What are herbivores?

eat only plants

What are carnivores?

eat only meat

What are omnivores?

eat both plants and animals

Organisms that reproduce asexually still have some genetic variation among themselves. This is due to a

mutation of DNA

Energy transfer

One directional

What is Evolution

The change in the phenotype of a population over time

Examples of Evolution

Fossil Records, Geology

Superposition

older fossils on are deeper in the Earth

Phenotype

The physical and functional traits of an organism, which result from the interaction of its genotype with the environment.

Natural Selection

organisms with inherited traits (Phenotypes) survive and have more babies, passing those traits to the next generation, (adulthood)

Fitness

The number of fertile offspring an individual has

sexual selection

Selecting inherited traits that give an advantage in mating/reproduction during adulthood

Macroevolution

Millions of Years

Microevolution

Short time frame (months)

Example of microevolution

Bacteria, viruses (mutation), antibiotic-resistant germs

What is an atom

Smallest unit of an element

Proton

positively charged particle (+) (1au) in Nucleus)

Neutron

no charge (1 au) - in nucleus

Electron

negatively charged particle (orbitals) (0au)

Atomic Number

number of protons

atomic mass

number of protons + number of neutrons

What is an isotope?

an atom with additional neutrons (^ mass)

What is a covalent bond?

Sharing Valence electrons (EX. CH4)

What is a polar covalent bond?

electrons are not shared equally

example of a covalent bond

Water (H2O)

What is a Valence Number

The number of electrons in the outermost orbital

What is an ion?

an atom that has gained or lost electrons

What is an ionic bond?

bond between oppositely charged ions

Examples of ionic bonds

NaCl

HCl

Phosphorus has an atomic number of 15 and an atomic mass of 31. The number of neutrons is

16

Phosphorus has an atomic number of 15 and an atomic mass of 31. The total Number of Electrons is

15

Carbon has an atomic number of 6 and an atomic mass of 13. The total Number of Electrons is

6

Carbon has an atomic number of 6 and an atomic mass of 13. The number of Neutrons is

7

Water flows...

Molecules are sticking and releasing from each other

surface tension

surface of ponds, etc

Cohesion

attraction of water molecules to each other

Adhesion

Attraction of water molecules to other substances

Solutes

Solvent (liquid) + solute

If a solute decreases the pH (increased the H+ concentration)...

It is an acid

If a solute increases the pH (decreases the H+ concentration)...

base

What are monosaccharides?

monomers of carbohydrates that contain ribose and glucose

What are disaccharides?

sucrose, lactose

What are oligosaccharides?

Form cell surface antigens (immune systems)

What are the components of polysaccharides?

Cellulose, starch, glycogen, Chitin

What is chitin?

forms the exoskeleton of arthropods (crabs, spiders, ants)

What is glycogen?

Stored form of glucose in the liver and muscles.

What is starch?

stored form of glucose

What is cellulose?

for structured support

Animals produce what type of polysaccharide

glycogn

Plants produce what type of polysaccharide

Starch and cellulose

Lipids

Secondary energy source compounds, such as fats, oils, cholesterol

What are Lipids function?

insulate the body heat against heat loss and provide a waterproof coating for fur

Saturated fat

Saturated with Hs - Still solid at room temperature

Unsaturated fat

less Hs (liquid at room temperature)

Cholesterol

Vitamin D

Animal Cell Membranes

Steroid hormone, estrogen, testosterone

Waxes and oils

Waterproof honeycomb, leal surface, fur, feathers

Insulation

Against heat loss and injury

Excess fats

stored as adipose tissue (animals)

Protein

Monomer Amino Acid

Functions of Protein

Forms muscle, hair, scales, horns, and beaks (structured proteins), transport of cell membranes

What are enzymes?

Proteins that speed up chemical reactions, antibodies, neurotransmitters, hormones (functional proteins)

What is denature?

Change 3d shape - loss of function

Nucleic Acids

DNA and RNA

Function of Nucleic Acids

Responsible for Heredity, directs cell activity, RNA (ribose), and deoxyribonucleic acid (DNA)

DNA

deoxyribose (double-stranded) (AGCT)

RNA

Ribose (single-stranded) (AGCU)

Carbohydrates

Broken down to glucose to provide energy, and cellulose to provide structural support to plant cells (Primary energy source)

Functions of Carbohydrates

Chitin (makes up the exoskeleton of insects and crustaceans) and Oligosaccharides (have a role in cell identity)

What does Cellulose, as a function of carbohydrate, provide?

structural support to plant cells