Exam 1 Review

Question 1

What is biology?

Answer 1

Biology is the study of life.

Question 2

What characteristics make up all living things?

Answer 2

• made of cells
• reproduce new individuals similar to themselves
• ability to sense and respond to environment
• die and decay
• can heal
• maintain homeostasis
• living species evolve

Question 3

What order do we use in the scientific method?

Answer 3

Make an observation -> formulate a hypothesis -> make predictions based on the hypothesis -> test the predictions

Question 4

How old is the earth?

Answer 4

Approximately 4.5 billion years old.

Question 5

Organic compounds such as fats, sugars, and amino acids formed spontaneously from _________?

Answer 5

The early atmospheric gases and energy.

Question 6

The compositions of the following polymers are true:

(1) Proteins are made of _______.
(2) Complex Carbohydrates are made of ____.
(3) Lipids or fats are made of _______.
(4) DNA is made of ________.

Answer 6

(1) Amino acids
(2) Sugars
(3) Fatty acids or glycerol
(4) Nucleotides

Question 7

Genetic information is passed on from parent to offspring in molecules known as ________.

Answer 7

DNA

Question 8

The following are true about lipids

(1) Triglycerides have _____.
(2) Lipids have ______ properties.
(3) Double bonds cause _____ in the carbon chains of fatty acids.
(4) Unsaturations cause a fat to be more ____.
(5) When a protein is added to a fat to make a lipoprotein the fat tends to become more ___A____ in water because ____B_____.

Answer 8

(1) three fatty acid chains
(2) nonpolar
(3) bends
(4) fluid
(5) A - soluble ; B - amino acid side-chains carry a charge.

Question 9

The following are true about protein structure:

(1) The primary structure of a protein refers to its ___________.
(2) The secondary structure of a protein refers to the ________.
(3) The tertiary structure of a protein refers to the _______.
(4) Two or more folded polypeptides comprise the _______.

Answer 9

(1) sequence of amino acids
(2) twisting and folding of the amino acid chain
(3) three dimensional shape of the folded chain
(4) quaternary structure of a protein

Question 10

Protein folds can be stabilized by _______________.

Answer 10

Hydrogen bonds, disulfide bridges, ionic bonds, and hydrophobic interactions

Question 11

The following are properties of proteins:

Answer 11

Denaturation can occur when a protein loses its’ shape due to extreme pH or high temperature.
Membrane spanning regions of proteins tend to be hydrophobic.
Proteins that are located on the surface of a cell membrane tend to have hydrophilic regions.
Soluble proteins tend to have a hydrophilic surface and a hydrophobic core.

Question 12

(1) Enzymes ______ the rate of a reaction.
(2) The active site of a single enzyme is capable of _______.
(3) Enzymes ________ the activation energy of a reaction.
(4) If the product of an enzyme is part of ____________, a drug that inhibits its production will have a side effect.

Answer 12

(1) increase
(2) binding a single substrate
(3) decrease
(4) multiple metabolic pathways

Question 13

The correct order of size from smaller to largest of the following is:
(Atom, eukaryotic cell, prokaryotic cell, electron, virus particle, molecule, proton)

Answer 13

Electron -> proton -> atom -> molecule -> virus particle -> prokaryotic cell -> eukaryotic cell

Question 14

What occurs during DNA replication?

Answer 14

A helicase enzyme unwinds the DNA.
Polymerase adds nucleotides to the DNA strand.
One in ten billion added nucleotides is a mistake and can result in a mutation.
DNA replication results in two molecules each containing an original strand and a newly replicated strand.
Ligase connects fragments on the lagging strand (Okazaki fragments)

Question 15

During the process of protein synthesis _________.

Answer 15

DNA is transcribed into RNA which is translated into protein.

Question 16

The following occurs during protein synthesis ______.

Answer 16

A ligand binds to the repression protein, alters its configuration, and releases it from the promoter region of a gene.
RNA polymerase binds to the gene.
RNA polymerase transcribes the strand of the DNA to make two complimentary copies of messenger RNA.
Transcription of a genetic sequence ends when RNA polymerase recognizes a sequence of bases complimentary to a stop codon.

Question 17

The following is true about translation:

Answer 17

Every three bases codes for an amino acid.
Ribosomal RNA binds to messenger RNA.
Transfer RNA has a three base anti-codon that is complimentary to the messenger RNA codon.
Ribosomal RNA has enzymatic activity.
Transfer RNA binds to amino acids.

Question 18

The following a re true about the movement of molecules in aqueous solutions:

Answer 18

Diffusion is the random movement of molecules from an area of higher concentration to an area of lower concentration.
Osmosis is a net movement of water across a semi-permeable membrane from an area of higher concentration to an area of lower concentration.
In a hypotonic solution there is less solute outside the cell which can cause the cell to swell and lose.
In a hypertonic solution there is more solute outside the cell which can cause a cell to dehydrate.
When salts are added to an aqueous solution the relative concentration of water is decreased.

Question 19

The following statements are true about bacteria:

Answer 19

Bacteria are the oldest known form of life existing today.
Bacteria do not have a nucleus.
Bacteria can reproduce asexually.
Bacteria do not have membrane bound organelles.

Question 20

The following statements are true about protists:

Answer 20

They may be once called organisms.
They have a nucleus.
Some survive by photosynthesis while others ingest or absorb their nutrition.
Members of the Kingdom Protista pre-date the animals, plants and fungi.

Question 21

The following are true about the plant, animal and fungi kingdoms:

Answer 21

Plants convert light energy into chemical bonds by photosynthesis.
Fungi absorb food substances from their surroundings.
Animals ingest food.
All three kingdoms possess nuclei and organelles.

Question 22

The function fo a cell membrane is to ____________.

Answer 22

Regulate what enters and leaves the cell.

Question 23

The following are gases from the early Earth’s atmosphere from which organic chemicals have been formed:

Answer 23

• nitrogen gas
• water vapor
• carbon dioxide gas
• methane gas

Question 24

(1) Archaebacteria live in extreme environments similar to those of the ____________.
(2) Eubacteria can live in _____________ on the earth.
(3) A single bacterial cell can reproduce to as many as ___________ in as little as ten hours.
(4) ______ are sometimes formed by bacteria when an environment becomes harsh.

Answer 24

(1) ancient earth
(2) modern environments
(3) a billion
(4) spores

Question 25

(1) Some bacteria need ________ to survive. (2) Some bacteria can only survive in environments ________ oxygen gas. (3) Some bacteria can only survive in environments _____ oxygen gas. (4) Some bacteria can survive in environments _____________ oxygen gas.

Answer 25

(1) oxygen gas (2) without (3) with (4) with or without

Question 26

Bacteria have been important in the worlds environment for the following reasons:

Answer 26

- they have produced nutrition for communities of living organisms through photosynthesis and chemosynthesis - they act as decomposers which release elements needed by living things from dead organisms - the metabolic processes of some bacteria first produced the oxygen gas in Earth’s atmosphere - they are the only organisms in the world that can convert atmospheric nitrogen into forms that are usable by other organisms

Question 27

The most primitive organisms to have a nucleus are the _______.

Answer 27

Protists

Question 28

_______ is the process by which one nucleus becomes two identical nuclei.

Answer 28

Mitosis

Question 29

_______ is the process by which one nucleus with two copies of each chromosome becomes four nuclei with one copy of each chromosome.

Answer 29

Meiosis

Question 30

Alteration of generations is a cycle of __(1)__ and __(2)__ phases in sexually reproducing organisms.

Answer 30

(1) haploid (1n) | 2) diploid (2n

Question 31

The following is true about evolution:

Answer 31

- a greater diversity of genes in offspring can result through meiosis because meiosis reduces the genetic material of an organism by half, and the other half of the genetic material of an offspring can then be donated by another individual. - according to the theory of evolution, the environment selects for individual organisms that possess genes which help the organism survive and reproduce - Species adapt to the environment b/c individuals that are less competitive die and their genes are lost from the population while the more competitive individuals survive - since the environments of the earth are not stable, species continuously evolve.

Question 32

The following are true about symbiotic relationships:

Answer 32

- Parasites harm their hosts - Commensalists do not harm their hosts. - Mutualists benefit their hosts - Parasites can evolve into commensalists which can in turn evolve into mutualists. - The relationship between algae and fungi that make up lichens, in which algae provide sugar for the fungus and the fungus provides moisture for the algae, is called mutualistic. - Mitochondria and chloroplasts may have began as symbionts of larger one celled organisms. - A protist that lives in the intestine of the termite and helps it digest wood is a mutualist relationship. - Human malaria is caused by a protist that is a parasite.

Question 33

The following are true about cells:

Answer 33

- Eukaryotic cells are highly compartmentalizations - Cells can absorb particles from the outside environment by endocytosis. - Cells can secrete molecules to the outside environment by exocytosis. - Cells can take in water from the outside environment by pinocytosis.

Question 34

The following are true about cell membranes:

Answer 34

- They are made of phospholipids - They have hydrophilic and hydrophobic layers - They are selectively permeable b/c they let nonpolar molecules through, but not polar molecules. - B/c water has a small size, it can pass through temporary gaps that form between the fatty acid chains. - Cholesterol interacts between the fatty acid chains and affects membrane fluidity.

Question 35

The following is true about the cytoskeleton:

Answer 35

- It gives shape to the cell. - It organizes cell components. - It is involved with internal movement of ogranelles and chromosomes

Question 36

The following is true about organelles:

Answer 36

- Peroxisomes contain the enzyme catalase that breaks down peroxide. - the smooth endoplasmic reticulum extends from the rough endoplasmic reticulum and is not associated with ribosomes - The golgi complex packages proteins and directs them for transport. - Lysosomes contain proteins for digestion

Question 37

The following is true about the cell cycle:

Answer 37

- A cell can spend weeks or years in the Gap I phase - DNA replication occurs in S phase - Production of proteins necessary for mitosis occurs in the Gap II Phase - Chromosomes are separated during the mitosis phase

Question 38

In order for a trait to evolve in a species it must benefit the individual organism by ________________.

Answer 38

helping it to survive and reproduce.

Question 39

The following true about the carbon cycle:

Answer 39

- Autotrophs transfer carbon from carbon dioxide in the atmosphere into organic molecules. - Heterotrophs transfer carbon from the cells of other organisms into their own cells. - Decomposers feed off of dead organisms. - Decomposers release carbon back into the atmosphere.

Question 40

The following is true with regard to respiration:

Answer 40

- Early organisms on Earth could carry out anaerobic respiration but not aerobic respiration. - Aerobic respiration produces more molecules of ATP than anaerobic respiration. Aerobic respiration can produce ATP with an original fuel supply of sugars or fatty acids. - Anaerobic registration can produce ATP from sugars - Anaerobic respiration results in the production of oxygen radicals that can mutate DNA.

Question 41

Concerning sexual and asexual reproduction:

Answer 41

- Asexual reproduction is advantageous b/c it can produce greater numbers of offspring - Sexual reproduction is advantageous b/c it can produce a greater variety of offspring - Sexual reproduction in humans can lead to offspring with traits from all four grandparents

Question 42

The following are true about fungi:

Answer 42

- They are eukaryotes - they can reproduce by sexual or asexual means - they act as Decomposers in the carbon cycle - they live most of their life cycle as haploid (1n) gametophytes - they exist in parasitic and in mutualistic relationships.