BIO Exam 2

What is the complementary sequence to the DNA strand 5'TCGATGG3'?

3'AGCTACC5'

Which organelle controls what the cell will look like and do?

4

Which of the following is most likely to have the greatest concentration of chloroplasts?

A cell that engates in photosynthesis

Why is the fact that the plasma membrane is amphipathic important?

A. It sets up the conditions for the membrane to be selectively permeable C. It sets up a hydrophobic barrier, while allowing hydrophilic molecules to collect close to the cell membrane

A. There are three groups of substances that can readily diffuse across the plasma membrane, list the three groups. B. What characteritics mark the substances that can't readily diffuse across the plasma membrane?

A. The three groups that can readily diffuse across the plasma membrane are small, non-polar molecules, dissolved gases, and water. Molecules like oxygen and carbon dioxide can easily diffuse across the semi-permeable plasma membrane. Water can also go through the plasma membrane by osmosis. Small, non-polar molecules like lipid-soluble molecules can also diffuse through the plasma membrane. B. Substances that can't easily diffuse across the plasma membrane are usually larger and polar in nature. However, they can still pass through by using channel proteins. For large and polar substances, they are unable to pass through the phospholipid bilayer easily. They need help to get across by using carrier or channel proteins.

Which of the following is more like plants than animals?

A. large central vacuole C. chloroplasts

Which of the following is found in both eukaryotic and prokaryotic cells?

B. DNA D. ribosomes

Which of the following is true?

Generally, the warmer the temperature the faster the rate of diffusion

Which of the following statements regarding the endomembrane system is false?

The endomembrane system is a system of interrelated membranes that are all physically connected.

How are genes used by cells to build proteins?

The genes in DNA direct the synthesis of an RNA molecule, which is used to build a protein.

Which of the following statements regarding membrane function is false?

The plasma membrane is the control center of the cell.

You're the manager of a factory that produces enzyme-washed blue jeans (the enzymes lighten the color of the denim, giving a "faded" appearance). When the most recent batch of fabric came out of the enzyme wash, however, the color wasn't light enough to meet your standards. Your quality control laboratory wants to do some tests to determine why the wash enzymes didn't perform as expected. Which hypothesis is most likely to be productive for their initial investigation?

The three-dimensional structure of the proteins may have been altered.

When viewing a specimen through a microscope, scientists use ____ to distinguish most internal components of the cell?

a beam of electrons

Which structure organizes the mitotic spindle during cell division?

a. 2

Resolution is the

ability of an optical instrument to show two close objects as separate.

The ____ is the bsic unit of life. It carries out all the characteristics of life.

cell

The cell wall of plants is made of __________, whereas the cell wall of most bacteria are made of, respectively:

cellulose: peptidoglycan

Which of the following serves as the microtubule organizing center?

centrosome

In E. coli, a bacterium, the genetic material is composed of ________.

circular, double-stranded DNA

The principal force driving movement in diffusion is the ____.

concentration gradient

The nucleoid region of a prokaryotic cell

contains the cell's DNA.

Which statement best describes osmosis?

diffusion of water from a greater to a lesser water concentration across a selectively permeable membrane

The fluid mosaic model describes the plasma membrane as consisting of

diverse proteins embedded in a phospholipid bilayer.

What is the combination of an electrical gradient and a concentration gradient called?

electrochemical gradient

The process by which molecules such as sodium ions are moved into cells along their concentration gradient with the help of membrane-bound carrier proteins is called

facilitated diffusion.

An animal cell placed in a hypotonic solution will:

gain too much water and lyse, break apart

The cholesterol associated with animal cell membranes

helps to keep phospholipids from being too close to one another.

Diffusion of a substance across the cell membrane is influenced by all of the following, except

hydrolysis of ATP.

What is the primary function of carbohydrates attached to the exterior of the cell membrane?

identification of the cell

The shape of a protein is specified by:

it's amino acid sequence

Which organelle breaks down old organelles and recycles its contents?

lysosomes

Which of the following is the site for ribosomal subunit synthesis?

nucleolus

A macromolecule that consists of a five-carbon sugar, a nitrogenous base, and a phosphate group. is a

nucleotide

In which situation would passive transport not use a transport protein for entry into the cell?

oxygen moving into a cell after oxygen deprivation

What is the name of the bond between amino acids called?

peptide bond

The process by which a cell engulfs a large foreign particle is called:

phagocytosis

Which of the following are only found in plants?

plasmodesmata

Most enzymes are what type of macromolecule?

proteins

Which plasma membrane component can be either found on its surface or embedded through the membrane structure?

proteins

Proteins that are made of more than one polypeptide subunit show what type of protein structure that proteins made of only one polypeptide subunit do not.

quaternary

The skin is the body's largest organ. It's made up of many different types of cells. Oils, produced by the sebaceous glands, prevent the skin from drying and splitting. The protein melanin, produced by melanocytes in the epidermis, protects the skin from the harmful effects of ultraviolet radiation. Sweat, released through ducts to the skin surface, helps to cool the body. The types of cells that produce these compounds have different numbers of specific organelles, depending on their function. Based on their function, you would expect melanocytes in the skin to have a higher than usual number of

ribosomes.

You look at a salivary gland cell, which makes and secretes a lot of enzymes to digest food. Which of the following organelles do you expect to find in great abundance?

rough ER

Which level of protein structure is stabilized by hydrogen bonds that form between the amino group of one amino acid and the carboxyl group of a nearby amino acid?

secondary

Amino acids can be distinguished from one another by

the chemical properties of their R groups.

Which of the following is typically only found in RNA?

uracil

Which of the following is not a nitrogenous base?

urea

As cell size increases, the

volume increases proportionally more than the surface area.