Tag: basics of cell

Questions Related to basics of cell

Extranuclear inheritance is a consequence of presence of genes in

  1. Lysosomes and ribosomes

  2. Mitochondria and chloroplasts

  3. Endoplasmic reticulum and mitochondria

  4. Ribosomes and chloroplast


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?

  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


Correct Option: B

Cell theory was given by_________________

  1. Schleiden

  2. Virchow

  3. Schwann

  4. All of the above


Correct Option: D
Explanation:

Cell theory was proposed by a German botanist, Matthias Schleiden and English zoologist, Theodor Schwann in the year 1839. Cell theory was considered as most acceptable theory which, elucidated the functioning of a cell. The cell theory includes the following points -
1) All living things are made up of cells.
2) The cell is the smallest living thing that can perform all the functions of life.   
Later on, in year 1855 Rudolf Virchow added a new point in cell theory that all cells must come from pre-existing cells, which was also known as "Omnis cellula e cellula".
So, the correct answer is option B.