Chapter 3

Question 1

What are the seven characteristics of life?

Answer 1

Life that:

• displays order
• harnesses and utilizes energy
• reproduces
• responds to stimuli
• exhibits homeostasis
• grows and develops
• evolves

Question 2

Define symbiosis

Answer 2

An inter specific interaction in which the ecological relations between two or more species are intimately tied together

Question 3

Alternate hypothesis

Answer 3

An explanation of an observed phenomenon that is different from the explanation being tested

Question 4

Oxidation

Answer 4

The removal of electrons from a substance

Eg) iron rust

Question 5

Endomembrane system

Answer 5

In eukaryotes a collection of interrelated internal membranous sacs that divide a cell into functional and structural compartments

Question 6

Transfer RNA

Answer 6

The RNA that brings amino acids to the ribosome for addition to the polypeptide chain

Question 7

Purine

Answer 7

A type of nitrogenous base with two carbon - nitrogen rings

Question 8

Endosymbiosis

Answer 8

A symbiotic association in which one symbionts or partner lives inside the other

Question 9

Protobiont

Answer 9

The term given to a group of abiotically produced organic molecules that are surrounded by a membrane or membrane like structure

Question 10

Primidine

Answer 10

A type of nitrogenous base with one carbon ring - nitrogen ring

Question 11

Stromatolites

Answer 11

Fossilized remains of ancient cynobacterial mats that carried out photosynthesis by the water splitting reaction

Question 12

Heterotrophs

Answer 12

An organism that acquires energy and nutrients by eating other organisms or their remains

Question 13

Ribozymes

Answer 13

An RNA based catalyst that is a part of the biochemical machinery of all cells

Question 14

Monomers

Answer 14

Identical or nearly identical subunits that link together to form polymers during polymerization

Question 15

Polymers

Answer 15

Substances whose molecules have high molar masses and are composed of a large number of repeating units

Among naturally occurs polymers there are proteins, starches, cellulose and latex

Question 16

Genome

Answer 16

The entire collection of DNA sequence for a given organism

Question 17

Macromolecules

Answer 17

A very large molecule assembled by the covalent linkage of smaller subunit molecules

Question 18

Radio metric dating

Answer 18

A dating method that uses measurements of certain radioactive isotopes to calculate the absolute age in years of rocks and minerals

Question 19

Translation

Answer 19

The use of information encoded in RNA to assemble amino acids into a polypeptide

Question 20

Selectively permeable

Answer 20

Membranes that selectively allow, impede or block the passage of atoms and molecules

Question 21

Transcription

Answer 21

The mechanism by which the information encoded in DNA is made into a complementary DNA copy

Question 22

Autotrophs

Answer 22

An organism that produces its own food source using CO2 and other simple inorganic compounds from its environment and energy from the sun or from oxidation of inorganic substances

Question 23

3 domains of life

Answer 23

Bacteria, Archaea, eukarya

Question 24

What is the importance of ribosomes?

Answer 24

They are responsible for protein synthesis. Free ribosomes produce essential proteins for internal cellular activity

Question 25

Why is DNA better than RNA for storing genetic information?

Answer 25

DNA is a stable storage for genetic information. DNA is 100x more stable than RNA.

• the material must be stable to avoid degradation of the genes when passing them on to the next generation

Question 26

3 key attributes of the modern cell:

Answer 26

1) a membrane defined compartment- the cell
2) a system to store genetic information and use it to guide the synthesis of specific proteins
3) energy transforming pathways to bring in energy from the surroundings and harness it to sustain life

Question 27

Liposomes

Answer 27

A lipid vesicle in which the lipid molecules form a bilayer very similar to a cell membrane