Lecture 6

Question 1

Where do genetic recombination events occur?

Answer 1

eukaryotes only

Question 2

What is fitness?

Answer 2

the ability to grow, survive, and reproduce

Question 3

Why do many eukaryotes also reproduce asexually?

Answer 3

• if there is no one to mate with
• if resources are limiting
• speed purposes
• if things are doing good for that genome in that environment, wouldn’t want to change it, so would produce asexually

Question 4

What is the nursing effect in eukaryotes when they reproduce asexually?

Question 5

What are the benefits of sexual reproduction for eukaryotes?

Answer 5

• sexual reproductio enhances the potential for evolution in multiple ways
• enhanced genetic diversity despite longer generation times
• multiple different alleles of each gene present within a population
• dominance/recessive
• potential for polyploidy

Question 6

what is the tradeoff that eukaryotes experience for longer generation time?

Answer 6

there would be evolutionary pressure to enhance genetic diversity in the next generation

Question 7

what is mitosis?

Answer 7

daughter cells have almost identical genotype to original cell, and same number of chromosome pairs

Question 8

what is meiosis?

Answer 8

homologous chromosomes synapse, some chromatid sections cross-over (genetic recombination) and the resulting pairs are separated (independent assortment) into four genetically different haploid cells (gametes or spores)

Question 9

what allowed for the evolution of meiosis?

Answer 9

the presence of diploidy

Question 10

What are three distinctive speciation mechanisms in eukaryotes that arise from initial diploidy?

Answer 10

• hybridization
• autopolyploidy
• allopolyploidy

Question 11

What is hybridization?

Answer 11

• n+n
• speciation mechanism
• will lead to a new species if it evolves in reproductive isolation

Question 12

What is autopolyploidy?

Answer 12

• 2n x 2
• speciation mechanism
• a eukaryotic cell going into division duplicates the chromosome before the cell becomes two daughter cells.
• if there is a mutation where the cell does not split apart, would cause the cell to have twice the number of chromosomes

Question 13

What is allopolyploidy?

Answer 13

• (n+n) x 2
• speciation mechanism
• GET DEFINITION

Question 14

what is alternation of generations?

Answer 14

• multicellular haploid and diploid phases
• happens in plants and some algae
• alternate between two different life stages

Question 15

Why have different life cycles evolved?

Answer 15

• evolutionary trend
• diploidy generates and stores more genetic variance
• expanded diploid phase
• reduced haploid phase

*go back to slides and understand, because unsure

Question 16

What are the protists?

Answer 16

• paraphyletic group
• most live in moist or aquatic habitats

Question 17

What are the photosynthetic protists?

Answer 17

• plant like organisms, but lack true roots, stems, or leaves
• generally photosynthetic
• generally aquatic
• lack vascular tissue or a cuticle

Question 18

how is light energy related to wavelength?

Answer 18

light energy is inversely proportional to its wavelength

Question 19

what are algae functionally equivalent to?

Answer 19

plants on land due to similar ecology q