bio 160 exam 1-4

Which of the following statements about water is false?

Ice is denser than liquid water

Which of the following statements regarding carbon is false?

Carbon has the ability to bond with up to six other atoms.

Which of the following options correctly pairs a polymer and its monomer?

DNA, nucleotides

Most animal cells are

embedded in an extracellular matrix.

The hydrogen atoms of a water molecule are bonded to the oxygen atom by ________ bonds, whereas neighboring water molecules are held together by ________ bonds

polar covalent; hydrogen

A pharmaceutical company hires a chemist to analyze the purity of the water being used in its drug preparations. If the water is pure, the chemist would expect to find

H2O molecules, H+ ions, and OH- ions.

A child dies following a series of chronic bacterial infections. At the autopsy, the physicians are startled to see that the child's white blood cells are loaded with vacuoles containing intact bacteria. Which of the following explanations could account for this finding?

A defect in the lysosomes of the white blood cells prevented the cells from destroying engulfed bacteria.

Cyanide inhibits mitochondrial function; as a result, the rate of

ATP synthesis decreases.

Which of the following statements about the functional groups of organic compounds is false?

All functional groups include a carbon atom

In plants, the process of photosynthesis produces glucose (C6H12O6) and oxygen from carbon dioxide and water. Which of the following options about photosynthesis is consistent with this statement?

All of the carbon atoms in glucose came from carbon dioxide.

Which of the following statements about pH is true?

An increase in hydrogen ion concentration means a decrease in pH scale units.

Which of the following statements about dehydration reactions is false?

Animal digestive systems utilize this process to break down food.

Which statement about ecosystems is false?

Bacteria and fungi recycle energy within an ecosystem.

Part complete Why do both mitochondria and chloroplasts possess circular chromosomes?

Both mitochondria and chloroplasts descended from free-living prokaryotes engulfed and maintained by early eukaryotic cells. more info=Endosymbiotic theory explains the basis for a variety of peculiar features shared between mitochondria, chloroplasts, and prokaryotes.

Which of the following is NOT a feature of both mitochondria and chloroplasts?

Both possess pigments active in photosynthesis

Glycolysis is the first step of cellular respiration, in which glucose is used to generate ATP to power the cell. The major chemical reaction that takes place in glycolysis (ignoring some other reactants and products) is the conversion of glucose (C6H12O6) to pyruvate (C3H4O3) and hydrogen ions (H+). Using this information, what is the correct equation for the glycolysis chemical reaction?

C6H12O6 → 2 C3H4O3 + 4 H+

Which statement about ecosystems is false?

Energy cycles from organisms through the atmosphere and back to the organisms.

What is the fundamental difference between covalent and ionic bonding?

In a covalent bond, the partners share a pair of electrons; in an ionic bond, one partner accepts electrons from the other.

Which of the following statements is not consistent with Darwin's theory of natural selection?

Individual organisms experience genetic change during their life spans to better fit their environment.

Which of the following statements about animal cell lipids is false?

Many lipids function as enzymes.

Which of the following statements about the cytoskeleton is false?

Once laid down, the elements of the cytoskeleton are fixed and remain permanently in place.

Which statement about the properties of life is false?

Organisms have an unchanging, constant internal environment.

Which of the following statements regarding the Golgi apparatus is false?

The Golgi apparatus decreases in size when a cell increases its protein production.

Which of the following statements regarding triglyceride molecules is false?

Triglycerides are hydrophilic.

You've made a hot drink by dissolving a teaspoon of instant coffee and a teaspoon of sugar in a cup of hot water. Which of the following statements is true?

You've just prepared an aqueous solution.

A hypothesis is

a proposed explanation for a set of observations.

The teeth of grain-eating animals (such as horses) are usually broad and ridged. This makes the teeth suitable for grinding and chewing. Meat-eating animals (such as lions) have pointed teeth that are good for puncturing and ripping flesh. This illustrates

a result of natural selection as well as the connection between form and function.

Which type of cytoskeletal protein is also involved in muscle contractions?

actin

Organic compounds

always contain carbon.

Glucose molecules are to starch as ________ are to proteins

amino acids

In the plasma membrane, the phospholipid heads

are hydrophilic and face outward toward the aqueous solution on both sides of the membrane.

You are told that the cells on a microscope slide are plant, animal, or bacterial. You look at them through a microscope and see cell walls and membrane-bound organelles. You conclude correctly that the cells

are plant cells.

Unlike animal cells, plant cells have ________ and ________. Unlike plant cells, animal cells have ________.

chloroplasts; cell walls; centrioles

Which of the following components is external to the plasma membrane?

extracellular matrix

You've been experiencing acid indigestion lately, and you'd like a quick fix for the problem. You do a little research on the Internet and discover that your problem is caused by excess stomach acid. In the pharmacy aisles, however, you're having a little trouble deciding what to purchase to address the problem. At the pharmacy counter, the clerk recommends that you purchase PEPCID AC or Alka-Seltzer tablets. If you were able to chemically analyze your stomach fluids 30 minutes after taking two tablets, you would find the same number of hydrogen ions. that the pH in your stomach has decreased. more hydrogen ions. fewer hydrogen ions.

fewer hydrogen ions.

Typically, nitrogen atoms are composed of electrons, protons, and neutrons. An isotope of nitrogen could

have more neutrons than the usual nitrogen atom

The results of dehydration reactions can be reversed by

hydrolysis reactions.

Which of the following structures is exclusively associated with prokaryotic cells?

nucleoid

Foods that are high in fiber are most likely derived from

plants.

A woman is having trouble becoming pregnant. Examination of her partner's sperm indicates that dynein feet are missing from the flagella in his sperm cells. A physician explains that this could interfere with fertility by

preventing the sperm from swimming to the egg cell.

In the equation 2 H2 + O2 → 2 H2O, the H2 molecules are ________ and the H2O molecules are ________.

reactants; products

After reading the paragraph below, answer the questions that follow. 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 pigment 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. Melanocytes use many enzymes to produce melanin. Based on their function, you would expect melanocytes in the skin to have a higher than usual number of

ribosomes.

The cells that produce hair made of protein contain a lot of ________, while the cells that produce the oils that coat the hair contain a lot of ________.

rough endoplasmic reticulum; smooth endoplasmic reticulum

able salt is formed when

sodium donates its single outer electron to chlorine.

To be scientifically valid, a hypothesis must be

testable and falsifiable.

The primary structure of a protein is

the amino acid sequence of the polypeptide chain.

Amino acids can be distinguished from one another by

the chemical properties of their R groups.

The tertiary structure of a polypeptide refers to

the overall three-dimensional structure.

Which of the following is dependent on the ability of water molecules to form hydrogen bonds with other molecules besides water?

the universality of water as a solvent

If you wished to clearly observe the organelles inside of a white blood cell, which type of microscope would you choose?

transmission electron microscope

A scientist performs a controlled experiment. This means that

two versions of the experiment are conducted, one differing from the other by only a single variable.

In an ecosystem, energy

typically flows from producers to a series of consumers