Biology Test 1

From smallest to largest, order the following physical catagories:

Cell, tissue, organ, organism, population, ecosystem

What is step 4 in the Scientific Method?

Conduct a critical experiment.

What is true of proteins, carbohydrates, and nucleic acids?

Each of these molecules is built from a common set of monomers.

Which of the following is/are part of accepted cell theory?

Every living organism is composed of one or more cells, and all living cells arise from preexisting cells.

The endoplasmic reticulum (ER) is a single membrane continuous with the nuclear envelope and a series of interconnected sacs throughout the cell. Why might it be beneficial to the cell for the ER to be continuous with the nuclear envelope?

It might be beneficial for the ER and nuclear envelope to be connected because it might make it easier for messages to get from the nucleus to the ER where proteins and lipids are made for the cell; this would most likely require the use of less energy.

Prokaryotes and eukaryotes are primarily distinguished by the absence or presence of internal membrane-enclosed organelles. Are prokaryotic cells at an evolutionary disadvantage because they lack organelles?

No; although prokaryotic cells are comparatively less efficient than eukaryotic cells, they are still able to carry out the processes necessary for survival and reproduction.

sorts proteins and lipids and sends them to their final destination

The Golgi apparatus

Give an example of a pseudoscientific claim that you have encountered in your everyday life, and explain why it has no scientific validity.

The interesting and significant aspect of all of the answers lies in theyour explanations as to why the claims are pseudoscientific.

Biology is ________ .

The study of living organisms

The proposed explanation for a phenomenon is BEST described as:

a hypothesis

In a scientific experiment, a control group:

can be compared with an experimental group to assess whether one particular variable is causing a change in the experimental group.

Char/Macro: act as short-term energetic molecules

carbohydrates

Char/Macro: function energy storage and structural support

carbohydrates

The element ________ makes up the chemical backbone of most molecules on planet Earth.

carbon

The smallest and most basic units of life are microscopic, self-contained units enclosed by a water repelling membrane and are called ________.

cells

Phospholipids are large organic molecules with a ________, polar phosphate head connected to ________, nonpolar fatty acid tails. How do these molecules arrange themselves to form a mostly impermeable barrier between a liposome and its environment?

hydrophilic; hydrophobic; They line up hydrophobic tails facing each other at the center line of the membrane with the hydrophilic heads facing outward, away from the center line of the membrane

Char/Macro: form the major framework of biological membranes

lipids

Char/Macro: used to create steroid molecules like cholesterol

lipids

The boundary that surrounds the contents of the nucleus is the

nuclear envelope

Char/Macro: store and transmit genetic information

nucleic acids

The genetic material found in all living things is made of building blocks called

nucleotides

Char/Macro: Participate in nearly every chemical reaction in living systems

proteins

Char/Macro: exhibit various levels of structure

proteins

Char/Macro: speed chemical reactions

proteins

Ribosomes are very small nonmembranous organelles that can either exist freely in the cytoplasm or be embedded in the endoplasmic reticulum of a cell; they are associated with the synthesis of

proteins

________ is the site where lipids destined for other cellular compartments are manufactured.

smooth endoplasmic reticulum

Many important cellular functions in eukaryotic cells occur within membrane-enclosed organelles, such as cellular respiration occurring within the mitochondria. The membranes of the mitochondria provide a place for enzymes needed for cellular respiration to anchor and function. Prokaryotic cells must also carry out respiration but do not have mitochondria. Where is the most likely place that enzymes needed for cellular respiration are anchored and functioning?

the plasma membrane