CHAPTER 3.1 Mechanisms and Processes of Evolution

Question 1

• descent with modification from a common ancestor
• change in gene frequency within a population

Answer 1

evolution

Question 2

Mechanisms of Evolutionary Change

MMGNM

Answer 2

Mutation
Migration/ Gene Flow
Genetic Drift
Natural Selection
Modern Evolutionary Synthesis

Question 3

Mechanisms of Evolutionary Change

• changes in the DNA
• happens in the central dogma

Answer 3

mutation

Question 4

what happens in central dogma?

Answer 4

In interphase, the DNA is duplicated, replicated and transcripted.

The DNA template separates, copies DNA template forming replicated DNA. The replicated DNA is attached to mRNA. The mRNA will then transcribe the DNA into RNA template. After transcribing, the RNA will move out of the nucleus, the mRNA strans will attach with rRNA. There are small rRNA under the RNA and the bigger rRNA at the top, the rRNA atop will be attach to tRNA. The tRNA translates mRNA template into protein or polypeptides.

Question 5

• hereditary material of life that carries genetic information from generation to generation
• backbone -
• 3 bonds Adenine and Thymine
• 2 bonds Cytosine and Guanine
• due to polarity, the shape “helix” forms

Answer 5

deoxyribonucleic acid DNA
sugar phosphate

Question 6

Mechanisms of Evolutionary Change: MUTATION

• the most that instigate evolution
• are inherited genetic alterations that occur in germ cells (sperm, eggs)

Answer 6

germline mutation

Question 7

Mechanisms of Evolutionary Change: MUTATION

• involves cells that do not participate in meiosis
• genetic alterations acquired by a cell that can be passed to the daughter cells of the mutated cell in the course of cell division
  Why does this type of mutation not instigate evolution?
  —

Answer 7

somatic mutation

Because they do not pass on to generations and are not acquired by offspring.

Question 8

Types of Mutation

Answer 8

Gene mutation
Chromosome mutation
Genome mutation

Question 9

Gene Mutation Types

Answer 9

Point Mutation
Frameshift Mutation

Question 10

Types of Mutation: Gene Mutation

• substitution of a single base in the third nucleotide position of codon

Answer 10

point mutation

Question 11

Types of Mutation: Gene Mutation: Point Mutation

• has no effect on the protein sequence

Answer 11

silent

Question 12

Types of Mutation: Gene Mutation: Point Mutation

• results in an amino acid substitution
• 1st and 2nd base nucleotide position in codon that causes change in proteins

Answer 12

missense

Question 13

Types of Mutation: Gene Mutation: Point Mutation

• substitutes a stop codon for an amino acid

Answer 13

nonsense

Question 14

Types of Mutation: Gene Mutation:

• insertion/ deletion of one or more bases
• causes shift in reading frame

Answer 14

frameshift mutation

Question 15

Types of Mutation: Gene Mutation: Frameshift Mutation

• shortened/ lengthened - nonfunctional protein sequence

Answer 15

insertion/ deletion

Question 16

Types of Mutation: Chromosome Mutation:

change in the amount of genetic information in chromosome because of:
—- loss of chromosomal segment, ex. Cri du Chat
—- gain/ repetition of chromosomal segment, ex. Charcot-Marie-tooth Disease

Answer 16

deletion
duplication

Question 17

Types of Mutation: Chromosome Mutation:

a similar amount of genetic information but the materials are rearranged
— reversal of region
— a segment of one chromatid attached to another chromatids segment

Answer 17

inversion
translocation

Question 18

Types of Mutation: Genome Mutation:

________ - presence of abnormal number of chromosomes; common on humans
________ - presence of more than two homologous chromosome sets; natural miscarriage
autoploidy
allopolyploidy

Answer 18

aneuploidy
polyploidy

Question 19

a. mutations are random - beneficial, neutral, harmful
b. not all mutations matter to evolution - ex. —
- single mutation has a large effect on the evolution
- but evolution happens in an —-

Answer 19

somatic mutations
accumulation of many mutations

Question 20

Causes of mutation

Answer 20

• DNA fails to copy accurately
• exposure to specific chemicals or radiation (external influences)

Question 21

Mechanisms of Evolutionary Change:

any movement of genetic materials/ individuals in a population to another population

Answer 21

gene flow

Question 22

Mechanisms of Evolutionary Change: GENE FLOW: Types of Gene Flow

• two population of the same species
• mediated by reproduction
• increases genetic variation of the population
• ex. grafting (Solanum lycopersicum and Solanum melongena)

Answer 22

vertical gene transfer

Question 23

Mechanisms of Evolutionary Change: GENE FLOW: Types of Gene Flow

• two different species
• known as lateral gene transfer
• bacteria/ viruses, endosymbionts to the host
• decreases genetic difference between different species

Answer 23

horizontal gene transfer

Question 24

Mechanisms of Evolutionary Change: GENE FLOW

Restrictions of Gene Flow

Answer 24

• physical barriers
• incompatible reproductive behaviors

Question 25

Mechanisms of Evolutionary Change:

• allele frequencies of a population change over generations due to chance or sampling error

ultimately separated

• random chance in allele frequencies independent to the influence of alleles’ to reproduce successully
• occurs in all populations of non-infinite size, but its effects are strongest in small populations (endagered species)

Answer 25

GENETIC DRIFT

Question 26

Mechanisms of Evolutionary Change: GENETIC DRIFT: Types of Genetic Drift

1. sharply reduced in size by natural disaster; survival of cheetah -
2. small group splits off from the main population to found a colony; Amish History, i.e. Ellis-van Creveld Syndrome (six-fingered dwarfism)

if genes are not varied, if pandemic happened, they could be wipeout

Answer 26

1. bottleneck effect
2. founder effect