BIOA01 - Deck 4 - Q151~Q194 Flashcards
Describe the example of Anolis lizards in the Caribbean.
How is this an example of convergent evolution?
Anolis lizards in the Caribbean are different species; they still develop similar traits, (like sticky toe pads for climbing trees), due to their environment.
Convergent evolution is when organisms that do not share a recent common ancestor become alike due to their habitat.
What was the Cambrian explosion?
Briefly describe what occurred with respect to animal marine life from 541-530 mya.
What were some key innovations?
What is the significance of the Burgess Shale in British Columbia?
The Cambrian explosion occurred from 541 to 530 mya.
Rapid and diverse evolution of marine animal life took place.
This explosion featured the emergence of many major animal groups and key innovations like hard exoskeletons and complex sensory organs.
The Burgess Shale in British Columbia is significant because it preserves exceptionally well-preserved fossils from this time, providing insight into the early evolution of complex life forms.
What is mass extinction?
How many mass extinctions has Earth experienced?
Mass extinction is when a significant number of different species on Earth die out in a short period of time.
Earth has experienced five major mass extinctions in its history.
How does background extinction relate to mass extinction?
Background extinction is the ongoing, slow rate of species extinction that occurs naturally over time, while mass extinction is a sudden event that leads to a significant & quick loss of species.
What was notable about the Permian-Triassic (aka end-Permian) mass extinction?
The Permian-Triassic mass extinction was the most severe mass extinction event in Earth’s history.
It resulted in the loss of approx. 96% of all marine species and approx. 70% of terrestrial vertebrate species.
What was notable about the Cretaceous-Paleogene (aka K-Pg) mass extinction?
The Cretaceous-Paleogene mass extinction occurred around 66 million years ago.
It caused the extinction of the dinosaurs and many other species due to a catastrophic event; (thought to be an asteroid impact).
Why does adaptive radiation often follow mass extinction?
Mass extinctions create vacant ecological niches, allowing surviving species to rapidly diversify and adapt to occupy these newly available habitats, leading to adaptive radiation.
Why are we now considered to be in the “Age of Mammals”?
Why was the time leading up to the K-Pg extinction considered to be the “Age of Reptiles”?
We are now in the “Age of Mammals” because mammals have become the dominant group of animals on Earth.
The time leading up to the K-Pg extinction was considered the “Age of Reptiles” because dinosaurs and other reptiles were the dominant land animals during that period.
Why do many consider us to be in a period of the 6th mass extinction?
Why does Prof. Fitzpatrick often say that humans have been the worst thing to happen to the Earth?
Many scientists believe we are in the 6th mass extinction due to the rapid loss of species caused by human activities such as habitat destruction and climate change.
Prof. Fitzpatrick’s statement highlights the significant impact of human actions on Earth’s biodiversity.
What are the eukaryotes?
Eukaryotes are organisms with a “true” nucleus enclosed in a membrane, (plants, animals, and fungi), while prokaryotes, (bacteria), lack this feature.
What are protists?
Why do they form a paraphyletic group?
Protists are diverse, usually unicellular eukaryotic microorganisms that form a paraphyletic group because they include all eukaryotes that are NOT animals, plants, or fungi, making them a mixed group with no common evolutionary ancestor.
Why is it important to study protists?
Studying protists is important because they are a diverse group of microorganisms that play crucial roles in ecosystems, can cause diseases, and offer insights into early evolutionary history.
Why are protists not prokaryotes?
Protists are eukaryotes because they have cells with a nucleus and membrane-bound organelles, whereas prokaryotes lack these features.
Why are protists different from plants and animals?
Protists are different from plants and animals because they are a diverse group of single-celled/simple multicellular organisms that differ from plants and animals in their diversity of structures, modes of locomotion, and nutritional strategies.
What is the protist that causes malaria?
How is it transferred to humans?
The protist that causes malaria is Plasmodium.
It is transferred to humans through the bite of infected female Anopheles mosquitoes.
Describe the events in the origin of eukaryotic cells.
Eukaryotic cells likely originated through a process called endosymbiosis, where simpler prokaryotic cells engulfed and formed mutually beneficial relationships with other cells, leading to the development of structures like mitochondria and chloroplasts within the eukaryotic cell.
What is endosymbiosis?
Endosymbiosis is like a “living together” partnership where one organism lives inside another, benefiting both.
For example, the relationship between mitochondria and our cells.
Describe the general steps in the primary endosymbiosis of mitochondria.
In primary endosymbiosis, a eukaryotic cell engulfs a free-living bacterium, forming a mutually beneficial relationship where the engulfed bacterium becomes the mitochondria over time.
Describe the general steps in the secondary endosymbiosis of chloroplasts.
In secondary endosymbiosis, a eukaryotic cell engulfs a photosynthetic eukaryote, forming a symbiotic relationship where the engulfed organism becomes a chloroplast within the host cell.
Describe how mitochondria are consistent with the endosymbiosis theory.
Mitochondria support the endosymbiosis theory because they have their own DNA, replicate independently within cells, and resemble free-living bacteria, suggesting they were once ancient bacteria engulfed by host cells.
Describe the typical structures of protists using the Paramecium.
Paramecium is a ciliated protist with a characteristic slipper-like shape, covered in cilia for movement. It has a macronucleus for general cell functions and a micronucleus for genetic exchange.
What is ingestive feeding?
Ingestive feeding is a method of obtaining nutrients in which organisms engulf and digest other particles or organisms.
How do protists move?
Protists move using whip-like structures called flagella, hair-like structures called cilia, or by constantly changing their cell shape through pseudopodia (false feet).
How do protists reproduce?
Describe the similarities between a haploid-dominated life cycle and a diploid-dominated life cycle.
Protists can reproduce asexually (binary fission) and sexually (conjugation).
The similarity between the two life cycles is that they both involve haploid and diploid stages, which alternate in the life cycle, with meiosis and fertilization occurring at different points.
