Evolution

Question 1

Theory of evolution by natural selection

1. _____ differences between individuals in a population
2. Heritable alleles produce _____ that affect the ability of an organism to survive and have offspring
3. Some individuals have phenotypes that allow them___, ___, and ___
4. Individuals with phenotypes allowing _____ will pass their alleles more frequently than those who do not
5. Overtime, alleles leading to more offspring will become _____, while others will become less abundant in the gene pool

Answer 1

Theory of evolution by natural selection

1. Heritable differences between individuals in a population
2. Heritable alleles produce phenotypes that affect the ability of an organism to survive and have offspring
3. Some individuals have phenotypes that allow them to survive longer, be healthier and have more offspring
4. Individuals with phenotypes allowing more offspring will pass their alleles more frequently than those who do not
5. Overtime, alleles leading to more offspring will become more abundant, while others will become less abundant in the gene pool

Question 2

Evolutionary fitness

Answer 2

How successful individual is on passing its alleles to future generations

Question 3

Two sources of genetic variation in populations

Answer 3

New alleles (mutations) and new combinations of existing alleles (sexual reproduction)

Question 4

Directional selection

Answer 4

polygenic traits follow a bell-shaped curve of expression, most individuals are around the average

as one extreme, gets eliminated, the population shifts toward the other extreme

short giraffes die, so there are more tall giraffes

Question 5

Divergent selection

Answer 5

Removes members near the average leaving those at either end.

The pop is split in two and could lead to a new species

Ex: small deer can hide and large deer can fight but medium are too big to hide and too small to fight so they die off

Question 6

Stabilizing selection

Answer 6

Both extremes of one trait are selected against, driving pop toward the average

Ex: Birds too large and too small are eliminated because they cannot mate

Question 7

Artificial selection

Answer 7

Humans intervene in the mating od animals and plants to achieve desired traits through controlled mating

Puppy mating

Question 8

Sexual selection

Answer 8

Animals don’t choose mates randomly, but have evolved to rituals and physical displays to attracting and choosing a mate

Question 9

Kin selection

Answer 9

Animals that live socially share alleles with others and sacrifice themselves for the sake of the alleles they share with another individual

A female lion sacrifices herself to save her sisters children

Question 10

Species

Answer 10

Group of organisms capable of reproducing with one another

Question 11

Reproductive isolation:

Two types

Answer 11

Keeps existing species seperate

Prezygotic and postzygotic

Question 12

Prezygotic reproductive isolation:

Postzygotic reproductive isolation:

Answer 12

Pre: prevent formation of hybrid zygote via barriers

Post: prevent development, survival or reproduction of hybrid individuals / prevent gene flow if fertilization does occur

Question 13

5 prezygotic barriers

Answer 13

Ecological: can’t mate, live in diff habitats so cannot access one another
Temporal: mate at diff times of day, season or year
Behavioral: rituals before mating
Mechanical: genital organs/structures not compatible for mating
Gametic: sperm from one species cannot fertilize the egg of another species

Question 14

3 post-zygotic barriers

Answer 14

Hybrid inviability: hybrid offspring does not develop or mature normally / die in embryonic stage
Hybrid sterility: born and develops normally bur doesn’t produce gametes / incapable of breeding
Hybrid breakdown: two hybrids mate successfully and produce hybrid offspring but this generation is biologically defective

Question 15

Cladogenesis

Answer 15

Creating new species from existing species

Question 16

Homologous structures

Answer 16

physical features shared by two species as a result of a common ancestor

dog feet and human feet suggest all came from ancestor with feet

Question 17

Analogous structures

Answer 17

serve same function in two different species but not due to the same human ancestor

flagellum of sperm and bacteria flagellum

Question 18

Binomial classification system

Answer 18

Each organism is given two names: species and genus

Genus capitalized and species not i.e., Homo sapien

Question 19

8 principle taxonomic categories and the mnemonic

Answer 19

Dumb King Phillip Came Over For Great Soup

Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species

Question 20

Early atmosphere was a reducing environment meaning

Answer 20

Electron donors were prevalent so no O2 was in the atmosphere because it is an electron acceptor

Lab recreations of the early atmosphere result in spontaneous formation of AA, carbs, lipids and ribonucleotides

Question 21

Abiotic synthesis

Answer 21

Absence of enzymes in the early atmosphere, metal ions on the rocks surfaces and clay acted as catalysts

Question 22

Proteinoids

Answer 22

Polypeptides made via abiotic synthesis

Question 23

Microspheres

Answer 23

Proteinoids in water spontaneously form droplets

Question 24

When lipids are added to microspheres, ___ form

Answer 24

Lipsomes

Question 25

Coacervates

Answer 25

Made with preexisting enzymes capable of catalyzing reactions

Question 26

Protobionists resemble cells in that they:

Answer 26

Contain a protected inner environment and perform chemical reactions

Can reproduce (too large: split in half)

Don’t have an organized mechanism of heredity

Question 27

What makes up protobionists?

Answer 27

Microspheres, liposomes and coacervates