Exam 1 BIOL

What is binomial nomenclature?

A two-name system for naming organisms using the genus and species/specific epithet.

What two components are needed for binomial nomenclature?

The genus name and the specific epithet/species name.

How is a scientific name formatted?

The genus is capitalized, the species is lowercase, and both are italicized or underlined.

In Homo sapiens, what is the genus?

Homo.

In Homo sapiens, what is the species/specific epithet?

sapiens.

Why is binomial nomenclature useful?

It gives organisms a universal scientific name across languages and regions.

What is taxonomy?

The science of classifying organisms.

Who developed the five-kingdom classification system?

Robert Whittaker.

What was Whittaker’s classification system based on?

Morphology and organism differences, including how organisms are structured and obtain energy.

Who proposed the three-domain classification system?

Carl Woese.

What are the three domains in Woese’s system?

Bacteria, Archaea, and Eukarya.

How did Woese’s system improve classification?

It used DNA/RNA evidence to show that Monera was too broad and should be split.

What kingdoms are included in Domain Eukarya?

Protista, Fungi, Plantae, and Animalia.

How do plants obtain energy?

They are autotrophs that make their own food through photosynthesis.

How do animals obtain energy?

They are heterotrophs that consume food from the environment.

How do fungi obtain nutrients?

They absorb nutrients from dead or decaying material.

Are fungi autotrophs or heterotrophs?

Heterotrophs.

What is a theory in science?

A broad explanation supported by a large body of evidence.

What is qualitative data?

Descriptive data, such as observations or yes/no information.

What is quantitative data?

Numerical data or measurements.

Can a hypothesis be proven true?

No. It can be supported, but not permanently proven.

What is the difference between a hypothesis and a theory?

A hypothesis is a specific testable explanation; a theory is broader and supported by much more evidence.

What are the three subatomic particles in an atom?

Protons, neutrons, and electrons.

Where are protons located?

In the nucleus.

What charge do protons have?

Positive.

What is the mass of a proton?

About 1 amu.

Where are neutrons located?

In the nucleus.

What charge do neutrons have?

No charge/neutral.

What is the mass of a neutron?

About 1 amu.

Where are electrons located?

In electron shells around the nucleus.

What charge do electrons have?

Negative.

What is the mass of an electron?

Essentially negligible/weightless for this class.

What does atomic number tell you?

The number of protons.

What does atomic mass equal?

Protons plus neutrons.

How do you calculate neutrons?

Atomic mass minus atomic number/protons.

In a neutral atom, how do protons and electrons compare?

They are equal.

If a neutral carbon atom has atomic number 6 and 7 neutrons, what is its atomic mass?

13 amu.

If sodium has atomic number 11 and atomic mass 22, how many neutrons does it have?

11 neutrons.

If fluorine has mass 20 and 11 neutrons, what is its atomic number?

9.

What are isotopes?

Atoms of the same element with the same number of protons but different numbers of neutrons.

How can you tell two atoms are isotopes?

They have the same number of protons but different atomic masses/neutrons.

What determines an element’s identity?

The number of protons.

What determines how atoms interact with other atoms?

Electrons, especially valence electrons.

What are valence electrons?

Electrons in the outermost shell that can interact with other atoms.

How many electrons can the first shell hold?

2 electrons.

How many electrons can the second shell hold in this class?

8 electrons.

How many electrons can the third shell hold for elements covered in this class?

8 electrons.

What does the octet rule mean?

Atoms tend to interact so their outer shell has 8 electrons.

What makes an atom inert?

A full outer electron shell.

What makes an atom reactive?

An incomplete outer electron shell.

If a neutral atom has 9 protons, how many electrons does it have?

9 electrons.

If a neutral atom has 9 electrons, how many are in the first shell and second shell?

2 in the first shell and 7 in the second shell.

Is a neutral atom with 9 protons reactive or inert?

Reactive, because its outer shell is not full.

What is an ion?

An atom or molecule with an electrical charge due to gaining or losing electrons.

What is a cation?

A positively charged ion.

How does an atom become a cation?

It loses electrons.

What is an anion?

A negatively charged ion.

How does an atom become an anion?

It gains electrons.

What is an ionic bond?

A bond formed when electrons are transferred and oppositely charged ions attract.

What is a covalent bond?

A bond formed when atoms share electrons.

What is a hydrogen bond?

A weak attraction involving a partially positive hydrogen and a full or partial negative charge nearby.

Which is stronger: covalent bonds or hydrogen bonds?

Covalent bonds are stronger.

What is a nonpolar covalent bond?

A covalent bond where electrons are shared equally.

What is a polar covalent bond?

A covalent bond where electrons are shared unequally.

What is electronegativity?

An atom’s attraction for electrons.

How does electronegativity affect electrons in a molecule?

The more electronegative atom pulls electrons closer to itself.

What partial charge does the more electronegative atom usually get?

Partial negative.

What partial charge does the less electronegative atom usually get?

Partial positive.

Why is water polar?

Oxygen pulls electrons more strongly than hydrogen, giving oxygen a partial negative charge and hydrogens partial positive charges.

What does pH measure?

Hydrogen ion concentration.

What is the formula for pH?

pH = -log[H+].

What pH is neutral?

pH 7.

What pH range is acidic?

Below 7.

What pH range is basic?

Above 7.

What do acids release or donate?

H+ ions.

What do bases release or accept/combine with?

They release OH- or combine with H+ ions.

As H+ concentration increases, what happens to pH?

pH decreases.

As OH- concentration increases, what happens to pH?

pH increases.

How much does H+ concentration change for each pH unit?

By a factor of 10.

If one substance is pH 3 and another is pH 5, which is more acidic and by how much?

pH 3 is 100 times more acidic.

What is the pH if [H+] = 1 x 10^-4?

pH 4.

What is the pH if [H+] = 1 x 10^-7?

pH 7.

What is a buffer?

A substance that resists major changes in pH by absorbing excess H+ or OH-.

What does hydrophilic mean?

Water-loving; interacts with water.

What does hydrophobic mean?

Water-fearing; does not interact well with water.

What kinds of molecules are usually hydrophilic?

Polar molecules and ions.

What kinds of molecules are usually hydrophobic?

Nonpolar molecules such as oils and fats.

What does amphipathic mean?

Having both hydrophilic and hydrophobic parts.

What is a macromolecule?

A large biological molecule made from smaller subunits.

What is a monomer?

One small subunit/building block.

What is a dimer?

Two monomers joined together.

What is a polymer?

Many monomers joined together.

What is dehydration synthesis?

A reaction that builds polymers by removing water.

What is hydrolysis?

A reaction that breaks polymers by adding water.

What is an isomer?

Molecules with the same chemical formula but different structures.

What is a monosaccharide?

A simple sugar and the monomer of carbohydrates.

What is a disaccharide?

Two monosaccharides joined together.

What is a polysaccharide?

Many monosaccharides joined together.

What is glucose used for?

Immediate energy for cells.

What is fructose?

Fruit sugar used as an energy source.