Exam 1 - Lecture 1 - Principles Of Life

Question 1

Regarding the origins of life, how is it thought nucleic acids come about?

Answer 1

Random collisions of molecules

Question 2

True or false: Substantial evidence supports the theory that there is a common ancestor for all life

Answer 2

True

Question 3

Regarding the origins of life, after the appearance of nucleic acids, what ability evolved to allow for further development?

Answer 3

Evolved the ability to synthesize proteins

Question 4

Regarding the origins of life: what is one of the reasons the development of the ability to form fatty acids is significant?

Answer 4

Because fatty acids are hydrophobic and can aggregate to form vesicles

Question 5

Regarding the origins of life: Why was the development of the ability to form vesicles significant?

Answer 5

Because they can create a micro-environment that’s separate from the external environment.

Different chemical reactions can take place in that micro-environment.

Question 6

Regarding the origins of life: What did reactions in vesicles lead to?

Answer 6

Formation of the first cells that were capable of reproduction

Question 7

What are prokaryotes?

Answer 7

The first living (single-called) organisms formed from cells

Question 8

What type of metabolism supported early life forms?

Answer 8

Anaerobic metabolism because the earth was devoid of O₂

Question 9

Regarding the origins of life, how did the ability of prokaryotes to perform photosynthesis change the environmental and evolutionary landscape?

Answer 9

By introducing oxygen (a byproduct of photosynthesis) into the atmosphere

Question 10

Regarding the origins of life: how did the appearance of oxygen in the atmosphere further change the earth’s landscape?

Answer 10

• Accumulation of ozone in the atmosphere
• Ozone accumulation led to terrestrial life forms
• Appearance of larger organisms who used aerobic metabolism (more energy to support larger size)

Question 11

What are organelles?

Answer 11

Membrane-bound compartments in living cells

Question 12

The development of larger cells, membrane-bound compartments, and a nucleus led to this “lineage” of cells.

Answer 12

Eukaryotes

Question 13

How did eukaryotic cells get organelles like chloroplasts and mitochondria?

Answer 13

Through endosymbiosis

Endosymbiosis - larger cells ingesting smaller cells, leading to them evolutionarily working together

Question 14

How did multicellular organisms originally come about?

Answer 14

Colonies of cells failed to separate after cell division

Question 15

What is cellular specialization?

Answer 15

When a cell or group of cells evolves to perform a specific function like nutrient acquisition or reproduction

Question 16

How did cellular specialization help further evolve multicellular life forms?

Answer 16

Led to the development of tissues

Question 17

What are mutations?

Answer 17

Alterations in the genome (can arise during replication)

⇒ this alters the future progeny

⇒ isolation can lead to further mutations

Question 18

What does the accumulation of mutations over time lead to?

Answer 18

Emergence of a new species

Question 19

What is binomial nomenclature?

Answer 19

How species are named; two words

First word is the genus

Second word indicates the species

Question 20

What are the 3 domains of life?

Answer 20

Bacteria, Archaea, and Eukarya

Question 21

What was the first kingdoms to emerge from the eukarya domain?

Answer 21

Protista (single-celled organisms)

Question 22

What is the model system?

Answer 22

The ability to extrapolate findings from one organisms and apply it to others because all organisms share common genetic code and macromolecules

Question 23

What is the definition of “genome”?

Answer 23

All genes encoded by a single organism

Question 24

What is bioinformatics?

Answer 24

The field where computer scientists and biologists organize, process, and compare genetic databases

Question 25

What is metabolism?

Answer 25

The sum of all chemical reactions required for life

Question 26

What is homeostasis?

Answer 26

Maintenance and regulation of the internal environment

Question 27

What is an example of how plants regulate homeostasis?

Answer 27

The use of their stomata to regulate their hydration

⇒ when stomata are closed (in arid conditions), water loss is prevented
⇒ when plant roots are saturated, stomata open

Question 28

How do individual cells regulate homeostasis?

Answer 28

By use of their plasma membranes to regulate and maintain internal homeostasis

Question 29

Definition of population

Answer 29

Interactions between organisms of the same species

Question 30

Definition of community

Answer 30

When many species interact with each other

Question 31

Definition of ecosystem

Answer 31

Communities that interact with an abiotic environment

Example: forest of trees interacting with soil

Question 32

Definition of ecology

Answer 32

The study of interactions between species and their environment

Question 33

What is evolution?

Answer 33

Change in genetic makeup of many populations

Question 34

What is natural selection?

Answer 34

When environmental conditions select for advantageous changes

Question 35

What is the definition of adaptation?

Answer 35

Structural, physiological, or behavioral traits that confer an increased probability for survival; results from natural selection

Question 36

What is a theory?

Answer 36

A well tested, scientific body of facts and principles used to make predictions about the world

Question 37

Who performed the experiment testing whether atrazine and other pesticides were responsible for the decline of frog populations?

Answer 37

Tyrone Hayes at UC Berkeley

Question 38

Why was atrazine in the groundwater leading to declining frog populations?

Answer 38

Male frogs were feminized and developed eggs in their testes instead of sperm