What are 3 pieces of evidence for the endosymbiotic theory?
Numerous lines of evidence exist, including that mitochondria and chloroplasts have their own circular DNA (prokaryotes also have circular DNA), mitochondria and chloroplasts have a double membrane (the inner membrane would have initially been the ingested prokaryote’s single membrane, and the outer membrane initially …
Do prokaryotes have rRNA?
Prokaryotic cells contain three rRNAs (16S, 23S, and 5S), which are formed by cleavage of a pre-rRNA transcript. Eukaryotic cells (e.g., human cells) contain four rRNAs.
What are the three parts of the cell theory?
The three parts of the cell theory are:
- All living things are composed of cells.
- Cells are the basic units of structure and function for living things.
- All cells come from pre-existing cells. Also, organisms grow by “adding on more cells” NOT by increasing the size of their cells.
What is the small dark structure in the nucleus that produces ribosomes?
The Nucleolus
The Nucleolus – The nucleolus is a membrane-less organelle within the nucleus that manufactures ribosomes, the cell’s protein-producing structures. Through the microscope, the nucleolus looks like a large dark spot within the nucleus.
What are the key differences between prokaryotic and eukaryotic cells?
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 60S and 40S make 80s?
The large sub-unit sediments at 50s, the small sub-unit sediments at 30s, but the two together (that is, the whole ribosome) sediments at 70s, not 80s. The same way an eukaryotic ribosome has a large sub-unit that sediments at 60s, a small one that sediments at 40s, but the whole structure sediments at 80s, not 100s.
Are ribosomes eukaryotic or prokaryotic?
Ribosomes are special because they are found in both prokaryotes and eukaryotes. While a structure such as a nucleus is only found in eukaryotes, every cell needs ribosomes to manufacture proteins.
What is called eukaryotic cell?
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 is an eukaryotic cell?
Eukaryotic cell refers to the cell whose genetic material is surrounded by the nuclear membrane, i.e. has a well-defined nucleus and other membrane-bound organelles. “Eu” means true and “karyon” means nucleus. All living organisms are made of cells.
Which is the genetic material of the eukaryotic cell?
DNA is the genetic material of the eukaryotic cell. The nucleus is surrounded by a complex nuclear membrane. Eukaryotic cells have mitochondria for cellular respiration. The cell wall is present in some of the eukaryotic cells like plant cells and is made of cellulose.
What organelles are found in a eukaryotic cell?
A eukaryotic cell contains membrane-bound organelles such as a nucleus, mitochondria, and an endoplasmic reticulum. Organisms based on the eukaryotic cell include protozoa, fungi, plants, and animals.
What is the structure of nucleus in eukaryotes?
The nucleus contains a single, linear DNA, which carries all the genetic information. The eukaryotic cell structure comprises the following: The plasma membrane separates the cell from the outside environment.