Bio exam 1

What is an element?

A pure chemical substance that cannot be further broken down

What describes a hydrogen bond?

Atoms with opposite partial charges attract each other.

Select all of the reasons why water is essential to life.

It plays a role in many chemical reactions. It regulates temperature. It dissolves a wide variety of substances.

Review this chapter's Investigating Life essay. Magnetosomes are adaptive because they allow bacteria to save energy as they move toward an optimal

O2 concentration.

Select all of the past scientific conclusions that were later revised due to technological inventions and new data analysis methods.

The Earth is flat. All organisms are either plants or animals. The Earth is the center of the universe.

Select the three components of the cell theory devised in the mid-1800s.

The cell is the fundamental unit of all life. All organisms are made of one or more cells. All cells originate from preexisting cells.

In an atom, each individual electron orbital (not energy level) may contain up to (blank) electrons

Two

When the bonds of two or more molecules are broken and new ones formed, this is called

a chemical reaction

A(n) ______ is an inherited characteristic or behavior which enables an individual to survive better than without the inherited characteristic.

adaptation

What type of reproduction passes genetic information from only one parent to the offspring?

asexual reproduction

An is the smallest unit of an element that retains the characteristics of the element.

atom

Determine the values of the following numbers for an electrically neutral atom of carbon-12, then place them in order from smallest at the top to largest at the bottom.

atomic number mass number total number of protons neutrons and electrons.

Molecules consist of two or more chemically linked ,which are the smallest "pieces" or units of elements.

atoms

primary producer

autotroph that obtains energy and nutrients from nonliving sources

Pairs of weak acids and bases that resist change in pH are called

buffers

What is an organic molecule with carbon, hydrogen, and oxygen in a 1:2:1 proportion?

carbohydrate

What is the basic unit of life and consists of a membrane enclosing water, DNA, and other chemicals?

cell

Select all of the biological levels of organization than occur in single-celled organisms.

cell molecules organelles atoms

What did Robert Hooke call the little units he observed when he viewed cork under lenses of glass?

cells

Whether bacterium or blue whale, every organism is made of

cells

gap junctions

channels for the exchange of substances between adjacent animal cells

What plant organelle is shown in the image and contains photosynthetic pigments?

chloroplast

Some protists, like Paramecium, are able to move through a watery environment with thousands of short extensions on the cell called

cilia

anchoring junctions

connect animal cells to the extracellular matrix or to adjacent animal cells in one place

What type of bond involves two atoms sharing electrons which travel around both nuclei?

covalent

What is the network of protein fibers and tubules inside the cell that provides support and aids in cell division and movement?

cytoskeleton

Ice cubes float in a glass of water because ice is less than liquid water.

dense

The fact that water is often the solvent in a solution demonstrates that water can

dissolve a variety of substances.

The internal membranes of several organelles are interconnected and form the ______ system of a eukaryotic cell.

endomembrane

Organelles called lysosomes contain ______ that break down food particles, old organelles, and other cellular debris.

enzymes

Key genetic sequences suggest that archaea are more closely related to members of domain ______ than they are to members of Domain Bacteria.

eukarya

Darwin and Wallace used the theory of ______ to hypothesize that a very long-tongued insect must exist that can pollinate flowers of the Angraecum sesquipedale on Madagascar.

evolution

Select all of the following that are characteristics of a scientific theory.

falsifiable can be used to make predictions encompass multiple hypotheses supported by a large body of evidence

tight junctions

fuse cell membranes of adjacent animal cells, forming a barrier

consumer

heterotroph that obtains energy and nutrients by eating other organisms

decomposer

heterotroph that obtains energy and nutrients from wastes and dead organisms

Using a process called ______, living organisms maintain a state of internal constancy or equilibrium, such as a constant range of temperatures, nutrients, or water.

homeostasis

In eukaryotic cells, the nucleus is an organelle that functions in

housing the cell's DNA

A(n). bond forms between a hydrogen atom with a partial positive charge on one molecule and another atom, such as oxygen, with a partial negative charge on an adjacent molecule.

hydrogen

Living organisms require a large temperature stimulus before the body temperature changes because the ______ bonds of water counteract molecular movement.

hydrogen

What type of bond forms between opposite partial charges on adjacent molecules or within a large molecule?

hydrogen

A type of chemical bond called a(n) (blank) bond forms between atoms when one atom releases a valence electron to become a cation, and the other atom uses this electron to complete its own valence shell and becomes an anion.

ionic

What type of microscope passes light through a transparent or thinly sliced specimen to generate true-color views of cells?

light microscope

What group of organic molecules does not dissolve in water and does not consist of long chains of monomers?

lipids

Anything that takes up space is defined as

matter

All cells have a cell that surrounds the cytoplasm and forms a boundary between the cell and its environment.

membrane

Cellular respiration extracts energy from food and takes place in the organelle called a

mitochondria

One subunit of an organic molecule is called a

monomer

Polymers, such as carbohydrates, proteins, and nucleic acids, consist of small subunits called linked together to form long chains.

monomers

Pure water has a(n) ______ pH.

neutral

Nucleotides are the monomers of polymers called acids, including DNA and RNA.

nucleic

What type of molecules are found in living things and contain both carbon and hydrogen?

organic

Tunnels called ______ occur in the cell walls of two adjacent plant cells and allow the cells to communicate and exchange materials with each other.

plasmodesmata

______ cells are the simplest forms of life and lack a nucleus.

prokaryotic

What type of organic molecule is composed of monomers called amino acids?

proteins

A hydrogen ion (H+) has only one subatomic particle, a(n) ______.

proton

Cohesion is the tendency of water molecules to

stick together

Carbohydrates are macromolecules that include

sugars

What is the science of naming and classifying organisms?

taxonomy

What type of cell junction is shown in the picture?

tight junction

Select all the roles that membranes play in cells.

transport substances into and out of the cell enclose organelles in eukaryotic cells receive and respond to external stimuli

plasmodesmata

tunnels for the exchange of substances between adjacent plant cells

Review chapter's Investigating Life essay. Many fungi, plants, bacteria, and animals produce toxic chemicals to

ward off potential competitors or predators.

In science, a theory is a broad explanation for a natural phenomenon that is

widely accepted