Biology Chapter 25 questions
Volvox
-Multicellular green algae that forms a monophyletic group with a single-celled alga and several colonial species -Have proteins homologous to those found in the cell wall of Chlamydomonas
What are the three periods
1. Initial diversification 2. Appearance of novel features 3. Rise of large eukaryotes
Which secondary endosymbiosis procedure is one cell, and which one is two?
Green algae is two and red algae is one cell
What underwent secondary endosymbiosis several times during eukaryotic evolution?
Green and red algae
What is the rise of large eukaryotes?
Maximum body size, taxonomic diversity, morphological variation increased
Consumers
Depend on producers for food
What causes malaria
Plasmodium
What are the oldest eukaryote fossils to be resolved taxonomically?
Red algae
What is appearance of novel features?
-Eukaryote fossils resolved taxonomically -Multicellularity, sexual life cycles, eukaryotic photosynthesis
What is the endosymbiont theory?
-Mitochondria and plastids were formerly small bacteria that began living within larger cells -Entered host cell as undigested prey or internal parasites -Mitochondria and plastids have circular DNA like bacteria
Examples of symbiotic protists that are parasites that harm their host
-Phytophthora ramorum: Causes sudden oak death -P. infestans: Related species that causes potato late blight
Where are the genes and cell characteristics of eukaryotes from?
Archaea and bacteria
Similarity between diplomonads and parabasalids
Both lack plastids
What is the closest living relatives of animals?
Choanoflagellates
What is the result of green algae after secondary endosymbiosis?
Euglenids and chlorarachiniphytes
What is initial diversification?
Eukaryotes had: Nucleus, membrane, cytoskeleton and varied in size and shape
Secondary endosymbiosis
Eukaryotic algal cells were ingested by heterotrophic eukaryotes
Which is more complex? Eukaryotic cells or prokaryotic cells?
Eukaryotic cells- have organelles
What are the structures in a eukaryote?
Membrane bound nucleus, numerous membrane bound organelles (endoplasmic reticulum, golgi apparatus, chloroplasts, mitochondria, etc), Several, rod-shaped chromosomes
What novel biological features evolved?
Multicellularity, sexual life cycles, eukaryotic photosynthesis
What two things go through secondary endosymbiosis?
Red and green algae
What is the result of red algae after secondary endosymbiosis?
Stramenopiles and alveolates
What does volvox have as structures?
The cells are embedded in an extracellular matrix containing proteins also homologous to those found in the Chlamydomonas cell wall.
What evidence supports the hypothesis that mitochondria and plastids evolved from prokaryotic endosymbionts?
They have a single circular chromosome similar to bacterial chromosomes And Their ribosomes are more like prokaryotic ribosomes than eukaryotic ribosomes
How did eukaryotes get the archaea and bacteria characteristics?
Through endosymbiosis- one organism lives inside the body or cell of another Endosymbionts become a single organism
What allows eukaryotic cells to have asymmetrical forms and to change shape?
Well-developed cytoskeleton
Producers
rganisms that use energy from light to convert CO2 to organic compounds
