Biology & Life

Question 1

Translation?

Answer 1

Genetic instructions are translated into an actual protein; the different types of RNA (transfer RNA and messenger RNA) work together to attach amino acids, brought to ribosome by tRNA to mRNA into a chain to make it proteins.

Question 2

Errors in DNA replication:

Answer 2

• Wrong base attached in base pair
• Extra base inserted into gene or entire sequence duplicated/eliminated
• Absorption of radiation or chemicals = mutation

Question 3

2 ways in which mutation can affect proteins

Answer 3

• Single based mutations e.g. changing ACC to ACA which does not change protein made by gene
• single-based mutations such as ACC to CCC which will change amino acid into a protein.

Question 4

Metabolism

Answer 4

Chemical reactions that occur in livnig organisms and are involved in providing energy or nutreitns to cells.

Question 5

Biochemical manufacturing process (buliding life) requires two basic things:

Answer 5

1. Source of raw materials with which to build new products
2. Source of energy to fuel metabolic process that breaks down old ones and manufacture new ones.

Question 6

ATP?

Answer 6

Adenosine triphosphate, molecule used to store and release energy for all its chemica lfacturing

Question 7

Lateral gene transfer

Answer 7

Organisms which can transfer entire genes to other organisms.
- e.g. bacteria resistance to antibiotics
- helps with insulin
- can change species more rapidly than mutation, but mutations are still underlying basis since they created genes in first place.

Question 8

Cells

Answer 8

Microscopic units in which living matter inside is separated from outside world by barrier called membrane.

Question 9

4 elements which make up about 96% of all living cells (even though there exist more than 20)

Answer 9

Oxygen
Carbon
Hydrogen
Nitrogen

Question 10

2 similarities in all living cells (which suggest common ancestor)

Answer 10

1. All pass on hereditary information in same basic way
2. Many chemical processes are same in all cells

Question 11

Why do we say life is carbon-based?

Answer 11

Because molecules that account for cell structure & function owe this to carbon.

Question 12

Why is carbon so important for life?

Answer 12

Because carbon can form double bounds and each atom can bond four other atoms at a time.

Question 13

Chemical bonds?

Answer 13

Sharing of electrons between individual atoms of a molecule.

Question 14

Which other element besides Earth can form four bonds at once + 3 reasons why it sucks?

Answer 14

Silicon.
1. Bonds are weaker
2. Does not form double bonds which limits range of chemical reactions
3. Silicon dioxide is solid :(

Question 15

Double bond in carbon?

Answer 15

Using two of its bonds to link with same atom. = stronger :)

Question 16

What does carbon suggest about life in the universe?

Answer 16

Carbon chemidtry is easy & common > carbon-based life would probably first within life and then reproduce so successfully that it would crowd out any other type of life.

Question 17

Carbohydrates + 2 functions?

Answer 17

Sugars and starches.
1. Provide energy to cells
2. Make important cellular structures

Question 18

Lipids + 2 functions?

Answer 18

1. Store energy
2. Key ingredients of membranes that make it possible for them to exist > thought to have been important because molecules trapped inside membranes prevents from dissolving and creates tiny factories that may have facilitated chemical reactions that led to life.

Question 19

Enzymes

Answer 19

Proteins comprised of amino acids linked together in a polypeptide chain. They’re crucial to nearly all chemical reactions within cells because they serve as catalysts for these reactions, as they accelerate reactions in which they’re involved.

Question 20

RNA

Answer 20

Second type of nucleic acids which helps carry out instructions in DNA.

Question 21

What 2 things are responsible for allowing cells to function according to precise & heritable instructions?

Answer 21

DNA + RNA.

Question 22

Extremophiles

Answer 22

Organisms that survive in extreme environments.

Question 23

Thermophiles

Answer 23

Microbes surviving in hot temperatures.

Question 24

Psychrophiles

Answer 24

Microbes surviving in cold temperatures.

Question 25

Endoliths

Answer 25

Microbes within the rock. Some estimates suggest total mass of subsurface organisms may exceed all life on Earth. They get energy from chemical reactions between water & surrounding rock, and nutrients from chemicals within rock and co2 filtered from surface.

Question 26

Endospores

Answer 26

Resting cells. Some can even survive in vacuum of space.

Question 27

Environments in which extremophiles can survive in?

Answer 27

Acidic, alkaline, salty, hot or cold.

Question 28

2 things of extremophiles which have implications for search terrestrial life?

Answer 28

1. Extremophiles evolved earlier suggests we should begin searching for similar extreme organisms
2. Fact that extremophiles can survive such broad range of conditions suggests that life may be possible in many more places than we thought.

Question 29

Species

Answer 29

Group of organisms that share common characteristics and are capable of interbreeding with one another.

Question 30

Genus?

Answer 30

Generic category to which species belongs.

Question 31

2 facts for Darwin’s theory of evolution / origin of species?

Answer 31

1. Overproduction & competition for survival.
2. Individual variation.

This points to natural selection.

Question 32

Natural selection

Answer 32

Advantegeous genetic traits will win out over less advantageous traits because they are more likely to be passed down through many generations.

Question 33

Artifical selection

Answer 33

Selective breeding of domesticated plants or animals by humans. (such as wild mustard leeding to cabbage, cauliflower, broccoli, kale,brussels sprouts, kohlrabi.

Question 34

Stromatolites

Answer 34

Rocks characterized by distinct, layered structure.

Question 35

Why is RNA simpler than DNA?

Answer 35

It only has one strand than two but still possesses hereditary information.

Question 36

Ribozymes?

Answer 36

RNA catalysts.

Question 37

What is chicken-egg dilemma in RNA?

Answer 37

RNA cannot replicate without enzymes and enzymes cannot be made without RNA.

Solution: RNA can catalyze biochecmical reactions in much same way as enzymes.

Question 38

3 potientially lethal events a microbe would have to survive to arrive on earth from migration

Answer 38

1. Impact that blasts it off home wolrld
2. Harsh environment of space
3. Plunge through our atmosphere

Question 39

2 reasons to consider migration?

Answer 39

1. Life does not form as easily as we have imagined, at least under conditions on Earth
2. Life arises so easily that we should expect to find life originating on any planet without suitable conditions

Question 40

2 issues of interplanetary migration in astrobiology

Answer 40

1. If we do find life on Mars we doubt whether its native or arrived from Earth
2. Possibility of life migrating raises question of whether we could distinguish between indigenous origin of life on Earth.

Question 41

Anaerobic

Answer 41

Life that does not require molecular oxygen

Question 42

Aerobic

Answer 42

Life that requires molecular oxygen (like humans)

Question 43

Symbiotic relationship

Answer 43

Both host and invading organism profit from living together.

Question 44

Phyla

Answer 44

classification below kingdoms

Question 45

Chordata

Answer 45

animals with internal skeletons

Question 46

Arthropoda

Answer 46

Animals with body features such as jointed legs, external skeleton, segmented body parts (insects & crabs)

Question 47

Cambrian explosion

Answer 47

Flowering of animal diversity

Question 48

4 factors contributing to cambrian explosion

Answer 48

1. Rise in oxygen level
2. Evolution of genetic complexity
3. Climate change –> evolutionary pressure that fueled cambrian explosion after snowball earth
4. Absence of efficient predators, as these did not exist