Lecture 5

Question 1

What is horizontal gene transfer?

Answer 1

transfer of geentic material within the same generation, between two members who are not genetically related

Question 2

Where are protists found in regards to the domains of life?

Answer 2

found in each of the groups within the eukarya domain

Question 3

Which cell is usually larger: bacteria or eukarya?

Answer 3

eukaryotic cells

Question 4

Due to the compartmentation due to membrance bound organelles in eukaryotic cells, what occurs?

Answer 4

complexities

Question 5

What happens with more compartmentation of cells?

Answer 5

more compartmentation causes more order, which allows for greater complexity and specialization

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Question 6

How are prokaryotic and eukaryotic cells similar?

Answer 6

they have structural differences, but very similar at the biochemical level

Question 7

What are distinctive structural characteristics of eukaryotes?

Answer 7

• internal membranes (membrane bound organelles, nuclear envelope with pores)
• chromosomes in pairs (diploid or polyploid)
• no prokaryotic rigid cell wall
• cytoskeleton
• larger ribosomes
• complex flagella

Question 8

What is the benefit of having internal membranes within eukaryotic cells?

Answer 8

• surface area is where reactions happen
• so having membranes within the cell increases the surface area where reactions can happen

Question 9

What is the benefit of eukaryotes not having a rigid cell wall?

Answer 9

means that the organisms can grow around organisms that it wants to consume (phagocytosis)

Question 10

What is the theory that may explain the presence of membrane bound organelles?

Answer 10

the serial endosymbiosis theory

Question 11

Describe how the nucleus possibily originated using the endosymbiosis theory.

Answer 11

*

Question 12

What evidence supports the serial endosymbiosis theory for the evolution of mitochondria and chloroplasts?

Answer 12

mitochondria and chloroplasts resemble bacteria in terms of:
* size and appearance
* having single circular chromosome
* reproduce by fission

chloroplasts and cyanobacteria
* both have chlorophyll a
* produce oxygen during photosynthesis

Question 13

for prokayotic micro organisms, what is a major source of genetic variation?

Answer 13

Horizontal gene transfer

Question 14

Why is the tree of life actually a web at its earliest ancestral level?

Answer 14

due to extensive horizontal gene transfers