Chapter 18 & 19 Flashcards Preview

Biology > Chapter 18 & 19 > Flashcards

Flashcards in Chapter 18 & 19 Deck (27)
Loading flashcards...
1
Q

Four Overlapping Stages

A
  1. origin of organic molecules
  2. organic polymers
  3. formation of boundaries
  4. RNA world
2
Q

Chemical Selection

A

a chemical within a mixture has special properties that cause it to increase in number compared to other chemicals in the mixture

3
Q

Fossil

A

preserved remains of past life on earth

-radioisotope dating

4
Q

Origins of Eukaryotic cells

A

hypothesized to involve a union between bacterial & archaeal cells

5
Q

Biological Evolution

A

heritable change in one or more characteristics of a population or species from one generation to the next

6
Q

Species

A

group of related organisms

7
Q

Evidence of Evolutionary Change

A
fossil records
biogeography 
convergent evolution 
selective breeding 
homologies
8
Q

Population

A

group of individuals of the same species that occupy the same environment & can interbreed with one another

9
Q

Gene pool

A

all the alleles for every gene in a given population

10
Q

Allele frequency

A

the number of copies of a species allele in a population divided by total number of all alleles for that gene in a population

11
Q

Genotype frequency

A

number of individuals with a particular genotype in a population divided by total number of individuals in a population

12
Q

Fitness

A

relative likelihood that one genotype will contribute to the gene pool of the next generation compared with the other genotypes

13
Q

Natural Selection Patterns

A

Directional selection
stabilizing
disruptive
balancing

14
Q

Genetic drift

A

change in allele frequencies due to random change

15
Q

Migration & Nonrandom mating

A

gene flow occurs when individuals migrate between populations having different allele frequencies

16
Q

Origin of organic molecules

A

nucleotides & amino acids were produced prior to the existence of cells

17
Q

Organic Polymers

A

nucleotides became polymerized to form RNA & DNA, & amino acids become polymerized to form proteins

18
Q

Formation of boundaries

A

polymers become enclosed in membranes

19
Q

RNA world

A

polymers enclosed in membranes acquired cellular properties

20
Q

Natural Selection

A

more offspring produced than can survive
compete for limited resources
individuals with better traits flourish & reproduce

21
Q

Biogeography

A

unique species found on islands & other remote areas

22
Q

Convergent evolution

A

2 different species from different lineages sometimes become anatomically similar b/c they occupy similar environments

23
Q

Homologies

A

similar structures due to descent from a common ancestor

24
Q

Directional selection

A

individuals at one extreme of a phenotype range have greater reproductive success in a particular environment

25
Q

Stabilizing selection

A

favors the survival of individuals with intermediate phenotypes & selects against those with extreme phenotypes

26
Q

Disruptive selection

A

favors survival of 2 or more different genotypes that produce different phenotypes

27
Q

Balancing selection

A

maintains genetic diversity