Academic Integrity: tutoring, explanations, and feedback — we don’t complete graded work or submit on a student’s behalf.

1.What is the Cell Theory? Cells arose by spontaneous generation All organisms a

ID: 53424 • Letter: 1

Question

1.What is the Cell Theory?

Cells arose by spontaneous generation

All organisms are composed of cells, and all cells are derived from other cells

All cells have a cell wall

2.The bases (nucelotides) of the two DNA chains are linked in the middle of the molecule by _________ bonds.

hydrogen

ionic

covalent

3.What organelles generates cellular energy?

chloroplasts

mitochondria

lysosomes

ribosomes

Golgi apparatus

4.A substance having a pH of 2 would best be described as

neutrala weak acid

a weak base

a strong base

a strong acid

5.What do hydrophobic and hydrophilic mean?

likes water,hates water

likes hydrogen, hates hydrogen

hates water,likes water

6.Choose the membrane molecule responsible for aiding passage of molecules into and out of the cell.

Phospholipids

Transmembrane proteins

Cell surface proteins

7.The stomach secretes strong acid to digest food. Why doesn’t this acid digest the stomach itself?

the stomach also secretes bases

the stomach has a protective mucus lining

incoming food absorbs the acid

8.When phospholipids are mixed with water their ____ interact with water and their ____ are repelled, forming a lipid bilayer.

hydrophilic heads; hydrophobic tails

hydrophobic tails; hydrophilic heads

hydrophobic heads; hydrophilic tails

hydrophilic tails; hydrophobic heads

9.The first energy shell of an atom contains a maximum of ________ electron(s).

one

two

four

eight

10.Wood and cotton cloth are composed of

starch

glycogen

chitin

cellulose

11.Which particles carry out atomic reactions? (protons, neutrons or electrons)

neutrons

protons

electrons

12.Why does NaCl dissolve in water?

the polar nature of water disrupts the ionic attraction between Na and Cl

the polar nature of water disrupts the covalent bond of NaCl

NaCL has hydrogen bonds and so does water

13.What is the basic reaction by which biological monomers form polymers?

hydrolysis

dehydration

mechanical displacement

14.What are the four major groups of biological molecules?

large, small, medium, microscopic

carbohydrates, lipids, proteins, nucleic acids

positive, negative, neutral, inert

15.The prokaryotic structure that would protect a cell from drying out

cell wall

nucleus

plasma membrane

16.The carbohydrate that is found in plant cell walls is

starch

cellulose

chitin

starch

17.Within a single molecule of water, the bonds between oxygen and hydrogen are.

covalent bonds

ionic bonds

hydrogen bonds

18.Why is it essential for a eukaryotic cell to compartmentalize its functions?

to keep charged molecules apart

to selectively modify, transport and degrade materials

to prevent larger molecules from absorbing smaller ones

19.Water is best described as which of the following?

an ion

a non-polar molecule

an atom

a polar molecule

20.Which cellular structure is responsible for packaging materials with the cell?

mitochondria

chloroplasts

lysosomes

ribosomes

Golgi apparatus

21.An ion is an atom that has

gained electrons

a positive charge

lost electrons

a negative charge

All of these are correct

22.Individual water molecules bind to each other through

covalent bonds

ionic bonds

hydrogen bonds

23.What kind is it when one atom takes an electron from another atom?

ionic

covalent

hydrogen

24What is the theory of Endosymbiosis?

mitochondria and chloroplasts are derived from bacteria and algae

organelles funtion in tandem

some organisms benefit for each other

25.H+ and Na+ have the same charge. Why does H+ “attack" other molecules much more strongly than Na+?

H+ has more neutrons

Na+ sa more total protons

H+ is an unsheilded proton

26.Ice floats on water because

the molecules are closer together in ice than in water

the molecules are farther apart in ice than in water

ice is more dense than water

27.If an atom has an outer shell that is full it is

highly reactive

highly likely to combine with other atoms

highly unlikely to combine with other atoms

28.Why is ice less dense than liquid water?

as more hydrogen bonds form, water molecules pack less tightly together

as more hydrogen bonds form, water molecules pack more tightly together

water binds with oxygen as it solidifies

29.What allows a cell to maintain it shape?

the cell takes up water to remain round

the Golgi apparatus

the cytoskeleton

30.Isotopes of the same element are different from one another in that they have a different number of

neutron

electrons

protons

31.How do eukaryotic cells form tissues?

they are each either positively or negatively charged and are attracted to each other

their cell membranes fuse

they connect via the extracellular matrix

32.The bases (nucelotides) in each of the chains of DNA are linked by _________ bonds.

hydrogen

ionic

covalent

33.Penicillin halts bacterial infections

by interfering with the construction of the cell wall

by stimulating a person's immune system

by damaging the cell membrane

by causing the DNA of a bacterium to mutate

34.How does a eukaryotic cell membrane keep the cytosol in and the extracellular water out?

the cytosol is attracted to the central nucleus

ionic repulsion of water

the cell membrane is impermeable to water

35.The atomic number of an atom or element is the number of

neutron

electrons

protons

36.Which polymer serves as the information storage molecule for cells?

Carbohydrate

Nucleic acid

Protein

Lipids

37.Eukaryotes such as animal and plants cells differ from prokaryotes in that prokaryotes

lack protein

lack DNA

lack a nucleus

38.Animals store energy in a polymer composed of many glucose molecules called:

glycogen

cellulose

chitin

starch

39.How can small molecules make their way past the cell membrane?

they pass through transmembrane channel proteins

they are hydrophobic

they are hydrophilic

40.Which is the main component of cell membranes?

Cholesterol

Sucrose

proteins

Phospholipids

Explanation / Answer

Cell theory: All organisms are composed of cells, and all cells are derived from other cells

The bases (nucleotides) of the two DNA chains are linked in the middle of the molecule by hydrogen bonds.

Mitochondria are cellular organelles, which generates cellular energy.

A substance having a pH of 2 would best be described as a strong acid.

Hates water, likes water

Transmembrane proteins

the stomach has a protective mucus lining

When phospholipids are mixed with water their hydrophilic heads interact with water and their hydrophobic tails are repelled, forming a lipid bilayer.

The first energy shell of an atom contains a maximum of two electron(s).

Wood and cotton cloth are composed of cellulose

neutrons

the polar nature of water disrupts the ionic attraction between Na and Cl

dehydration

carbohydrates, lipids, proteins, nucleic acids

cell wall

cellulose

hydrogen bonds

to selectively modify, transport and degrade materials

a polar molecule

Golgi apparatus

All of these are correct

hydrogen bonds

ionic

mitochondria and chloroplasts are derived from bacteria and algae

H+ is an unsheilded proton

the molecules are farther apart in ice than in water

highly unlikely to combine with other atoms

as more hydrogen bonds form, water molecules pack less tightly together

the cytoskeleton

neutron

they connect via the extracellular matrix

covalent

by interfering with the construction of the cell wall

the cell membrane is impermeable to water

protons

Nucleic acid

lack a nucleus

glycogen

they pass through transmembrane channel proteins

Phospholipids

Hire Me For All Your Tutoring Needs
Integrity-first tutoring: clear explanations, guidance, and feedback.
Chat Now And Get Quote