Multicellular Eukaryotes

Question 1

Name 4 characteristics of protists

Answer 1

1. Single celled eukaryotes
2. Diverse structure
3. Capable of ‘animal-like’ behaviour
4. Membrane bound organelles

Question 2

Name the TACK superphylum

Answer 2

Thaumarchea
Aigarcheota
Crenarcheota
Korarchaeota

Question 3

What types of protists are typically included in Euryarchaeota?

Answer 3

halophiles, methanogens, hyperthermophiles

Question 4

What do Crenarchaeota include?

Answer 4

hyperthermophiles, thermoacidophiles

Question 5

What do Thaumarchaeota include?

Answer 5

hyperthermophiles present in marine and soil environments

Question 6

Describe the endosymbiosis theory

Answer 6

Idea that mitochondria and chloroplasts are thought to have evolved as a result of the engulfment of a bacteria, resulting in a symbiotic relationship as energy produced gave cell an evolutionary advantage

Question 7

What is the evidence for the endosymbiosis theory?

Answer 7

Mitochondria have a cell membrane, circular DNA that is transcribed independently and they divide very similarly to bacteria

Question 8

What is a didinium and how does it provide possible evidence for the endosymbiosis theory?

Answer 8

A carnivorous protozoan that stuns prey by using a paralytic dart
engulfs prey via phagocytosis

Question 9

What 3 theories describe the emergence of the eukaryotic nucleus?

Answer 9

1. Envagination of the early eukaryotic membrane
2. Endosymbiont bacteria
3. Internally synthesized membranes formed the nucleus

Question 10

Which nucleus formation theory has the strongest support?

Answer 10

Endosymbiont theory

• Bacteria engulfs archaea and then forms membrane structures around it
• Plasma membrane envagination breaks off to become cell nucleus membrane and endoplasmic reticulum

Question 11

Describe the inside-out theory?

Answer 11

• association of an archea and a bacteria via archea growing on membrane surface and interacting with the bacteria
• energy from bacteria allows for the growing of a lipid bud until the bacteria is internalised
• cell closes in on itself with the archea forming the nucleus, bacteria form mitochondria and the membrane envagination of the archea forms nucleus membrane and ER

Question 12

What is epigenetics?

Answer 12

Series of modifications of the DNA which modify the phenotype without modifying the genotype, resulting in an epigenome. Important for determining cell type.