How does current theory explain the origin of a nucleus in eukaryotic cells?
There is no current theory that explains the origin of the nucleus. The current theory is that chloroplasts are descendants of symbiotic cyanobacteria that lived within eukaryotic cells. If we look at their respective genomes, however, we see that the cyanobacteria have many more genes than do chloroplasts.
Which of the statements is an important consequence of the evolution of diatoms and Coccolithophorids?
Terms in this set (9) Which of the following is an important consequence of the evolution of diatoms and coccolithophorids? The silica and calcium carbonate contained in these organisms became a primary source of sediments on the deep seafloor. How do eukaryotic cells generate and maintain genetic diversity?
Which is the oldest group of eukaryotes to be recognized in the fossil record?
Bangiomorpha pubescens
Which of the organisms is currently one of the most important photosynthetic organisms in the oceans?
“Phyto” refers to plant and “plankton” refers to a floating lifestyle. Despite their classification as phytoplankton, diatoms are technically not plants since they are single-celled rather than multicellular like plants. Diatoms are one of the most important photosynthetic organisms in the ocean.
Which algae are most closely related to plants quizlet?
Green algae have traditionally been considered protists, but we study them along with land plants for two reasons: They are the closest living relatives to land plants.
What is the main difference between the two hypotheses for the origin of the eukaryotic cell?
What is the main difference between the two hypotheses for the origin of the eukaryotic cell? Only one involves the conversion of a proteobacterium to a mitochondria. One hypothesizes that engulfment of a proteobacterium occurred after formation of the nuclear envelope rather than before.
What is the origin of eukaryotic cells?
Eukaryotic cells arose through endosymbiotic events that gave rise to the energy-producing organelles within the eukaryotic cells such as mitochondria and chloroplasts. Mitochondria appear to have originated from an alpha-proteobacterium, whereas chloroplasts originated as a cyanobacterium.
Do all eukaryotes and prokaryotes contain linear DNA?
In most eukaryotic cells, DNA is arranged in multiple linear chromosomes. In contrast, most prokaryotic cells generally contain a singular circular chromosome. However, linear chromosomes are not limited to eukaryotic organisms; some prokaryotic organisms have linear chromosomes as well, such as Borrelia burgdorferi.
Whats is a eukaryote?
Eukaryote, any cell or organism that possesses a clearly defined nucleus. The eukaryotic cell has a nuclear membrane that surrounds the nucleus, in which the well-defined chromosomes (bodies containing the hereditary material) are located.
What are the three major differences between prokaryotic and eukaryotic cells?
Eukaryotic cells contain membrane-bound organelles, such as the nucleus, while prokaryotic cells do not. Differences in cellular structure of prokaryotes and eukaryotes include the presence of mitochondria and chloroplasts, the cell wall, and the structure of chromosomal DNA.
What does prokaryote mean?
Prokaryote, also spelled procaryote, any organism that lacks a distinct nucleus and other organelles due to the absence of internal membranes. Bacteria are among the best-known prokaryotic organisms. The lack of internal membranes in prokaryotes distinguishes them from eukaryotes.
What is the best definition of a prokaryote?
Scientific definitions for prokaryote Any of a wide variety of one-celled organisms of the kingdom Monera (or Prokaryota) that are the most primitive and ancient known forms of life. Prokaryotes lack a distinct cell nucleus and their DNA is not organized into chromosomes.
What are prokaryotes give an example?
Bacteria are examples of the prokaryotic cell type. An example is E. coli. In general, prokaryotic cells are those that do not have a membrane-bound nucleus.
What are the three types of prokaryotes?
Prokaryotes come in various shapes, but many fall into three categories: cocci (spherical), bacilli (rod-shaped), and spirilli (spiral-shaped) (Figure 1).
Which is the oldest prokaryote?
The oldest known fossilized prokaryotes were laid down approximately 3.5 billion years ago, only about 1 billion years after the formation of the Earth’s crust. Eukaryotes only appear in the fossil record later, and may have formed from endosymbiosis of multiple prokaryote ancestors.
What is the main difference between the two main groups of prokaryotes?
There are several differences between the two, but the biggest distinction between them is that eukaryotic cells have a distinct nucleus containing the cell’s genetic material, while prokaryotic cells don’t have a nucleus and have free-floating genetic material instead.
Why are prokaryotes split into two domains?
Prokaryotes are divided into two domains because studies on the organisms determined that there are enough differences to place them into their own…
What is the difference between prokaryotes and eukaryotes?
Prokaryotes are organisms that consist of a single prokaryotic cell. Eukaryotic cells are found in plants, animals, fungi, and protists. They range from 10–100 μm in diameter, and their DNA is contained within a membrane-bound nucleus. Eukaryotes are organisms containing eukaryotic cells.
What are the two major types of eukaryotes?
There are four types of eukaryotes: animals, plants, fungi, and protists. Protists are a group of organisms defined as being eukaryotic but not animals, plants, or fungi; this group includes protozoa, slime molds, and some algae.
What are the similarities and differences of prokaryotic and eukaryotic cells?
Like a prokaryotic cell, a eukaryotic cell has a plasma membrane, cytoplasm, and ribosomes, but a eukaryotic cell is typically larger than a prokaryotic cell, has a true nucleus (meaning its DNA is surrounded by a membrane), and has other membrane-bound organelles that allow for compartmentalization of functions.
What are at least two major differences between eukaryotic and prokaryotic cells?
Comparing prokaryotes and eukaryotes The primary distinction between these two types of organisms is that eukaryotic cells have a membrane-bound nucleus and prokaryotic cells do not. The nucleus is where eukaryotes store their genetic information.
What are at least two major differences between eukaryotic and prokaryotic cells and one major similarity between the two?
What are at least two major differences between eukaryote and prokaryote cells and one major similarity between the two? Prokaryotes are typically single cell organisms, while eukaryotes cells are cells contained within organisms. Eukaryotes and prokaryote cells contain very different components within the cell.
What organelles are found in both prokaryotic and eukaryotic cells?
- Prokaryotes and eukaryotes are the two different types of cells.
- Eukaryotic cells contain membrane-bound organelles, such as the nucleus, endoplasmic reticulum, mitochondria while prokaryotic cells do not but the ribosome is the only organelle that can be seen in both prokaryotic and eukaryotic cells.