Tag: cell and cell organelles

Questions Related to cell and cell organelles

In yeast mitochondria UGA codes for:

component of the cell cell and cell organelles cell organelles cell: the unit of life biology cell as structural and functional unit basics of cell

  1. Termination codon

  2. Initiation codon

  3. Tryptophan

  4. Tyrosine glycerate concentration

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Correct Option: A

Which of the following organelles contain circular DNA.

component of the cell cell and cell organelles cell organelles cell: the unit of life biology cell as structural and functional unit basics of cell

  1. Peroxisomes and mitochondria

  2. Mitochondria and Glgicomplex

  3. Chloroplasts and Lysosomes

  4. Mitochondria and chloroplast

Show answer
Correct Option: D
Explanation:
Mitochondria and chloroplast are the organelles that show the presence of circular DNA.
The circular DNA in chloroplast is self-replicating and is known as cpDNA. It is involved in the synthesis of some intra-organelle proteins.
The mitochondrial circular DNA is self-replicating and is called mt DNA. It is also involved in the synthesis of some intra-organelle proteins.
Thus the correct answer is option D.

How many organelles of a eukaryotic animal cell possess their own DNA?

component of the cell cell and cell organelles cell organelles cell: the unit of life biology cell as structural and functional unit basics of cell

  1. 1

  2. 2

  3. 3

  4. 4

Show answer
Correct Option: B
Explanation:

Mitochondria and chloroplasts are the only two organelles of animal and plant cells that contain their own DNA. They not only contain their own DNA, but they also have their own ribosomes. These little protein-making machines are given information from the DNA to build certain proteins.

So, the correct option is '2'.

Mitochondria and chloroplasts are believed to be bacterial endosymbionts of cells because

component of the cell cell and cell organelles cell organelles cell: the unit of life biology cell as structural and functional unit basics of cell

  1. They have their own nucleic acids.

  2. Their membranes resemble those of cyanobacteria.

  3. They do arise de novo.

  4. All of the above.

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Correct Option: A
Explanation:

Mitochondria and Chloroplasts are the only cell organelles other than nucleus coated with double membrane. They have their own DNA and protein synthesizing machinery as well. One explanation for a cell organelle to have its own DNA is that these organelles were separate organisms. The chloroplast was an autotrophic cyanobacteria and the mitochondria was a separate heterotrophic organism which later on became lodged into a eukaryotic cell as endosymbionts.

Extranuclear inheritance is a consequence of presence of genes in

component of the cell cell and cell organelles cell organelles cell: the unit of life biology cell as structural and functional unit basics of cell

  1. Lysosomes and ribosomes

  2. Mitochondria and chloroplasts

  3. Endoplasmic reticulum and mitochondria

  4. Ribosomes and chloroplast

Show answer
Correct Option: B
Explanation:
DNA and RNA is the genetic material that carries information from one generation to another. Apart from this genetic material in the nucleus, the cytoplasm also contributes to the inheritance of some characters. Such characters are cytoplasmic inherited characters and this phenomenon is called as cytoplasmic inheritance. It is also called extra nuclear inheritance, because in this type of inheritance factors lies outside the nucleus of the cell. The cytoplasm contains various cell organelles including mitochondria, chloroplast are regarded as semi-autonomous as they contain their own genetic material-DNA. Hence cytoplasmic inheritance involves inheritance of mitochondrial DNA and/or chloroplast DNA.
So, the correct answer is 'Mitochondria and chloroplasts'.

Which of the following is an incorrect statement about the possible endosymbiotic origin of chloroplasts and mitochondria?

component of the cell cell and cell organelles cell organelles cell: the unit of life biology cell as structural and functional unit basics of cell

  1. They are of appropriate size to be descendants of bacteria

  2. They contain their own genome and produce all their own proteins

  3. They contain circular DNA molecules not associated with histones

  4. Their membranes have enzymes and transport systems that resemble those found in the plasma membranes of prokaryotes

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Correct Option: B

A prokaryotic cell lacks 

botany cell and cell organelles gram staining microbiology: organisms in industry cell wall and cell membrane

  1. Cell wall

  2. Cell membrane

  3. Cytoplasm

  4. Nucleolus

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Correct Option: D
Explanation:

A prokaryotic cell lacks a nucleolus. A prokaryote is a single-celled organism that lacks a membrane-bound nucleus, mitochondria, or any other membrane-bound organelles. All the intracellular water-soluble components are located together in the same volume enclosed by the cell membrane, rather than in separate cellular compartments.