Chapter 1 Flashcards
What are 7 components of a eukaryote?
1.) cytoskeleton
2.) endomembrane system
3.) primary genome
4.) 80s ribosome
5.) mitochondria
6.) plastids
7.) sexual reproduction
What is the difference between the genome of prokaryotes and eukaryotes?
Prokaryotes have a circular genome and primarily have plasmids whereas eukaryotes have a linear genome and often do not have plasmids, eukaryotes have a nucleus and a nuclear envelope, and there are specialized organelles which prokaryotes do not have.
What are the 3 domains of life?
1.) Archaea
2.) Bacteria
3.) Eukarya
What is complexity?
Specialized cells that make up tissues and then organs and these cells are able to encode genes that independently operate that tissue/organ such as kidneys lungs.
What are protists?
This is a heterogeneous collection of organisms that are eukaryotic however are not animals, plants, or fungi.
What is a root?
This is the initial beginning or ancestor of the tree of life.
What is a node?
This is the point where the tree branches split and derive new species through evolution however the basal is referring to common ancestors.
What is the cytoskeleton?
This is the structure of the cell that supports it externally and internally and enables motion and connectivity within the cell.
What are microtubules?
These are structures that consist of tubule dimers and assist in the cellular processes of cell division for example.
What are microfilaments?
These are thin strips of proteins that are found in almost all eukaryotes.
What are flagella and cilia?
These are thin structures that provide motion to cells through standing waves.
What is the difference between the cilia and flagella?
The flagella is longer and not in abundance like the cilia.
What are the dynein motor proteins?
They provide the cilia and flagella with motion through the 9+2 Arrangement and allow it to bend.
What is a prokaryote?
An organism that lacks certain double membraned organelles and a nucleus.
What is a eukaryote?
An organism that has certain double membraned organelles and a nucleus.
What is the nucleus for?
To protect the DNA and regulate transcription and gene expression.
What is the mitochondria?
A double membraned organelle that originated from a prokaryote through endosymbiosis and generates ATP.
What is the chloroplast?
A double membraned organelle that originated from a prokaryote through endosymbiosis and stores energy for photosynthesis.
What is the golgi apparatus?
Is involved in cellular motion and transporting material.
What is the endoplasmic reticulum?
The proteins and lipids that are synthesized are then modified and transported.
What is a vesicle?
This is a sac that fuses with the plasma membrane and through exocytosis and endocytosis allows for material to get in and out and this was the evolution of predation since prey can be ocnsumed in a similar fashion.
What are the main differences between the plant and animal cells?
1.) Central vacuole
2.) Cell wall
3.) Chloroplasts => plastids
4.) Shape
5.) Cellulose
What is a plasmid?
These are small circular pieces of DNA more often found in prokaryotes than eukaryotes however they are not essential to the survival of the organism.
What are ribosomes for?
This is a structure consisting of a large and small subunit that translates the mRNA to proteins.
Why is surface area important?
More surface area allows for more metabolic processes which allows for more ATP.
What is a plastid?
This is a category in which the chloroplast is under.
What is sexual reproduction?
The process of producing offspring that involves the genetic material of 2 parents thus the progeny are not identical to the parents.
What is asexual reproduction?
The process of producing offspring via 1 parent thus the progeny are identical to the parent.
What are the 3 methods of introducing variation among organisms?
1.) Vertical gene transfer
2.) Horizontal gene transfer
3.) Mutation
What is vertical gene transfer?
The inheritance of genetic material from one generation to the next.
What is horizontal gene transfer?
The movement of genetic material between organisms other than by descent.
By which process did the chloroplast and mitochondria become organelles?
Endosymbiosis - intially these organelles started as a prokaryote one in the other and then developed and became dependent on one another.
What are the main differences between the chloroplast/mitochondria and other organelles?
1.) Reproduce by fission
2.) Circular DNA
3.) DNA is closer to that of a prokaryote than the eukaryote that is the host
4.) Double membrane
5.) Size
6.) 70s ribosome
7.) Certain proteins that are found in the membrane
What was the Great Oxygenation Event?
This was a progressive boom of oxygen in the atmosphere. Initially the oxygen being produced by the cyanobacteria was staying in the ocean and being dissolved as iron oxide however steadily the oxygen was penetrating to the surface and that allowed eukaryotes to flourish.
What is the symbiotic hypothesis?
That organisms of different genomes came together to benefit each other in a relationship, however, the way in which the different organisms evolved into multicellularity was not explored.
What is the syncytial hypothesis?
All of the cells of the same genome are all connected together instead of undergoing the cellular division process thus the cell has many nuclei and a lot more DNA. Also a single unicellular organism could have developed internal membrane partitions around each of its nuclei.
What is the colonial hypothesis?
The cooperation of the cells of the same species that led to the development of a multicellular organism. Thus it is when organisms come together so they have the same genome however they have specialized cells that continue to perform individual processes.
What caused the Great Oxygenation Event?
Free oxygen accumulation from cyanobacteria and the evidence is in the banded rocks such as iron oxide which dissolved the ocean oxygen thus not letting the oxygen penetrate to the atmosphere.
Why was there a long gap before an oxygenated atmosphere?
Anoxygenic photosynthesis and banded iron formation.
What changed?
The ocean chemistry, the evolution of complexity, and photosynthetic organsisms.
What does the evolution of spores and gametes tell us?
That sexual reproduction is evolving.
How did the gree algae survive the daphnia?
By keeping its daughter cells inside after budding therefore increasing its size.
What are the advantages of multicellularity?
- Division of labour
- Increased size
- Avoid predation
- Exploit new
environments - Storage
- Increased feeding
opportunities
- Protected internal
environment - New metabolic functions
- Enhanced motility
- Increased traction in
currents or wind - Share information with
other cells
What are some challenges with large and multicellular organisms?
- Intercellular
communication- Diffusion
- Gap junctions
- Bulk flow
- Nerves
- Cell adhesion
- Structure and support
- Homeostasis
- Defend cells against
hostile environments
- Defend cells against
- Reproduction and
growth- Sex, fertilization,
development, and
growth
- Sex, fertilization,
What is the difference between a prokaryote and a eukaryote?
Prokaryotes lack a nucleus whereas eukaryotes do have a nucleus.
What is the disadvantage of asexual reproduction?
Since the parent and progeny are identical negative traits can also be passed down.
When did the mitochondria form into an organelle?
1.5 Billion years ago
When did the plastid form into an organelle?
2 Billion years ago
What is the nuclear envelope?
A layer of protection for the nuleus against the cytoplasm.
What is the nuclear pore complex?
It is the largest protein complex and it is the site for the exchange of large molecules such as proteins and RNA.
What is chromatin?
These are sections of DNA with their respective proteins.
What is the structure of the endoplasmic reticulum?
There are snakk vesicles called cisterna and each one is a single membrane bound sac filled with ER lumen, and this lumen can exist as Rough ER or Smooth ER.
How does the golgi apparatus manage the movement of proteins out of the cell?
The proteins are marked for their final destination for instance proteins secreted by the cell are transported to the plasma membrane in secreatory vesicles which then release their contents to the exterior by exocytosis.
How does the golgi apparatus manage the movement of proteins into the cell?
In a similar method wesicles may form to bring the proteins into the cell through a similar pinching method.
What is exocytosis?
It is the process of the vesicle fusing with the membrane and moving the content of the vesicle inside.
What is endocytosis?
It is the process of material collecting at one point on a membrane and then that section pinches forming a vesicle and letting it into the cell.
What are lysosomes?
These are membrane bound vesicles that contain more than 30 digestive enzymes and these are only in animal cells because the plant cells have the large vacuole that they use for digestion.
What is a lysosomal enzyme?
It acts as the garbage disposal of the cell and eats anything that doesn’t work or bacteria.
What is phagocytosis?
This is the process of consuming bacteria or cellular debris
What is the structure of the mitochondria?
There is an inner and outer membrane, the inner membrane is folded many times to increase surface area, and the space between the membrane is filled with a fluid known as the matrix.
What is the centrosome?
This is the centre where the microtubules form and radiate out from as in mitosis.
What are centrioles?
These are barrel like structures that form at the mid point and they are also formed from microtubules.
What are intermediate filaments?
These are structures that extend from the cell centre in a similar structure to microtubules.
What is the structure of the chloroplast?
There is an inner and outer membrane, there are stacks of sacs called the thylakoid, each thylakoid has a membrane, each thylakoid is filled with lumen, and around the thylakoid is the stroma.
What is cell adhesion?
Binding cells together
What is a cell junction?
The space between the cell and providing direct communication.
What is the extracellular matrix?
Supporting and protect the cell by providing mechanical linkes e.g., muscle and bones.
What is an anchoring junction?
These are belts that run entirely around the cell. There is a sub type known as desmosomes which are intermediate filaments that connect to the cytoplasm. Another is adherens which are microfilaments that connect to the cytoskeleton.
What is a tight junction?
These junctions are found in organs and hold the membrane or cell very tightly together.
What is a gap junction?
These are pathways for molecules and ions to travel through.
What is an autotroph?
These are plants and they are able to synthesize their own food from sunlight.
What is a heterotroph?
These are are organisms such as animals that require a different source for their food.
When did the oxygen levels start to rise and lead to the banded iron?
2.5 Billion years ago
Where did the oxygen come from?
There were photosynthetic prokaryotes known as cyanobacteria and they would oxidize the water molecules producing oxygen which would build up in the atmosphere and eventually when enough had built up it led to the Great Oxygenation Event and the byproduct was diversity of organisms.
What are the 6 pieces of evidence for endosymbiosis for chloroplasts and mitochondria?
1.) The shape and size is similar to a prokaryote
2.) A cell cannot make them
3.) They each have their own genome
4.) They can complete translation and transcription
5.) Both have electrion transport chains and ATP synthase
6.) RNA sequencing informed geneticists that these organelles belong to the bacterial tree.
What is the pathway to endo/exocytosis?
ER produces the proteins or synthesizes the molecules => The golgi complex transfers these proteins to the plasma membrane through the secretory vesicle
=> End/exocytosis.
What is the central vacuole?
It is a plantae organelle that takes up 90% of its volume, where the molecules are stored, and digestion takes place.
Why did bacteria and archaea remain simple?
The bacteria and archaea remained simple compared to eukaryotes because the more complex an organism is the more energy that it requires.
What was the energy barrier problem for eukaryotes?
Not having enough energy to supply the multicellularity of the eukaryote.
What was the solution to the energy barrier problem?
The mitochondria was able to generate more ATP through aerobic respiration compared to anaerobic respiration.
What was the primary benfit of multicellularity?
The labour was divided among the specialized cells which then gave rise to the specialized organs and tissues.
