Exam 2 Bio

Phanerozoic Timeline

0.6-present

Phanerozoic evolution

Colonization of land 0.4 bya

Proterozoic timeline

2.5-0.6 bya - a period that preceded the Phanerozoic, characterized by significant geological and biological developments.

Archaean timeline

4-2.5 bya

Hadean timeline

4.6-4 bya

• the earliest eon in Earth's history, marked by the formation of the Earth and the development of the crust.

Creation of prokaryotes

3.5 bya - present

Creation of atmospheric oxygen

2.7 bya - present

Creation of single-celled Eukaryotes

1.9 bya - present

Creation of multicellular Eukaryotes

1.25 bya - present

Creation of animals

0.7 bya - present

Colonization of land

0.4 bya - present

Protocells

vesicles with a membrane that grows and self-replicates

Issotopes

Atoms of an element with the same number of protons, but different neutrons and atomic masses

Radiometric Dating

method used to find a fossils age by measuring amount of isotopes absorbed

Endosymbiosis

When a prokaryotic cell engulfs a small cell that evolves into a mitochondrion

How did eukaryotes originate

Endosymbiosis

Phylogenetics

the evolution of a species, with a focus on the history and lines of descent

Systematics

classifies organisms into groups based on physical traits and DNA

Taxonomy

Giving names to species to organize them

Homology

Similarity due to a shared ancestor

Analogy

similarity due to convergent evolution

Divergent evolution

when related species evolve differently due to differing environments

Convergent evolution

when species form different lineages adapt to their environment in similar ways

Symplesiomorphy

a shared ancestral trait, carried through all descendants

Synapomorphy

a shared derived trait/newer unique trait evolving from a common ancestor; evolutionary character unique to a particular clade.

Ingroup

species currently being studied; how they relate to one another

Outgroup

related, but diverged from common ancestor first

Binary fission

method of asexual reproduction; single prokaryotic cell duplicates by dividing into two daughter cells

Genetic Recombination

how prokaryotes reproduce; combining DNA from different sources

Used to generate evolution hypothesis due to blood lines

Homology

What theory do scientists use that explains that mitochondria evolved before plastids?

Serial Endosymbiosis

What is a property that protocells share?

Fluid-filled vesicles

Which of the following supports the endosymbiosis theory?

Chloroplast and mitochondria have a double membrane

Which of the following is NOT a stage in simple cell production that took place on early Earth?

Cells divide through mitosis

What is the process that described the evolution of mitochondria in eukaryotes?

Endosymbiosis

Which dates back to 4.6 bya?

The formation of Earth

What is the scientific name for the oldest known fossils, which rocks formed by the accumulation of sedimentary layers on bacterial mats?

Stromatolites

How long ago did the permian mass extinction occur?

252 mya

How long ago did the Cretaceous Mass extinction occur?

66 mya

What are protocells and why are they important in the origin of life?

A simple cell-like structure that may have provided a controlled environment for chemical reactions leading to life.

Protocells exhibit which pair of properties?

Replication and Metabolism

Why are alkaline hydrothermal vents considered more suitable for the development of the stable organic compounds on early Earth?

They release water with a high pH at moderate temperature, which supports developments of stable organic compounds.

What is responsible for the sixth mass extinction?

Humans

How is the age of fossils determined?

Radiometric Dating

What does the Cambrian explosion refer to?

The sudden appearance of fossils that look like modern animal phyla

What is the role of protists in aquatic ecosystems?

Primary producers and from the base of many food webs.

How old are the oldest eukaryotic cell fossils?

1.8 bya

Which are due to convergent evolution?

Analogies

What is the group that roots the tree?

Outgroup

What can the length of a branch in some phylogenetic trees represent?

Number of genetic changes

What does a polyphyletic group consist of?

Distantly related species but not the most recent common ancestory

What is another term for the basal taxon?

Outgroup

What is a paraphyletic group?

Group of species that includes the ancestor and some of its decscendants

What three factors contribute to genetic diversity in Prokaryotes?

Genetic recombination, rapid reproduction, and mutation

What is the mating process used to exchange DNA in bacteria?

Conjugation

Some prokaryotes have fimbriae that allow them to do what?

Stick to their substrate

What are three factors in the genetic diversity of prokaryotes?

Mutation, rapid reproduction, and genetic recombination

What is NOT a characteristic of prokaryotic cells?

They contain a nucleus

How can you tell gram-positive bacteria?

They have cell walls with large amounts of peptidoglycan

How can you tell gram-negative bacteria?

Contain an outer membrane with lipopolysaccharides

Which organisms were the first living organisms to evolve on Earth?

Prokaryotes

Eukaryote cell walls are made of what?

Chitin and cellulose

What is the difference between bacteria and archaea?

One’s cell walls have peptidoglycan, and the other doesn’t.

What type of gene transfer is used by a virus to spread its DNA to bacteria?

Transduction

What does it mean when a prokaryote exhibits taxis?

The ability to move towards or away from a stimulus

What is true about prokaryotes?

They are the most abundant organisms on Earth due to their ability to adapt to diverse environments.

Genetic recombination results…

From crossing over during meiosis.

What is a defining characteristic of angiosperms?

Development of flowers and enclosed seeds

Which feature is unique to prokaryotic cells compared to eukaryotic cells?

Circular DNA without histones

What type of bacteria is Spirochetes?

Helical gram-negative heterotrophs that cause lyme disease

What is the purpose of pili?

Hair like structures allowing prokaryotes to exchange DNA

What are ciliates?

Protist that use cilia to move and feed

Invertebrates have an exoskeleton composed mainly of what?

Chitin

The name SAR comes from what major clades?

Rhizarians, stramenopiles, and alveolates

What are part of the supergroup Unikonta?

Protist, animals, and fungi

Which of these have delicate, symmetrical internal skeletons made of silica?

Radiolarians

Which protist group causes sleeping sickness in humans?

Kinetoplastids

What do paramecium use for motility?

Ciliate

What kingdom contains the closest relatives of plants?

Protists

What are the supergroups of Eukaryotes?

Excavata, SAR, Archaeplastida, and Unikonta

Slime molds are…

Mycetozoans

Parasites of animals are…

Apicomplexans

Kinetoplast have…

a single mitochondrion with an organized mass of DNA

What is included in the Excavata clade?

Diplomonads, parabasalids, euglenozoans

Archaeplastida supergoup includes…

red algae, green algae, and plants