Tag: cell-the basic unit of life

Questions Related to cell-the basic unit of life

Messenger RNA is formed in

  1. Nucleus

  2. E.R.

  3. Ribosomes

  4. Golgi apparatus


Correct Option: A
Explanation:
  • Messenger RNA is formed in the nucleus.
  • The process by which mRNA is formed from the DNA present in the nucleus is called transcription.
  • The mRNA formed within the nucleus is transported out of the nucleus and into the cytoplasm of the cell and gets attached to the ribosomes. 
  • It then synthesis proteins in the cytoplasm which is required by the cell for various cellular activities.
  • So, the correct answer is 'Nucleus'.

Two membrane envelop is found in

  1. Mitochondria, Golgi apparatus and chloroplast

  2. Mitochondria, nucleus and chloroplast

  3. Nucleus, Golgi apparatus and endoplasmic reticulum

  4. Nucleus, ribosome and chloroplast


Correct Option: B
Explanation:
  • The mitochondria is a double-membraned cell organelle, known as the powerhouse of the cell which is present in all eukaryotic cells.
  • The nucleus is enclosed by the nuclear envelope which is a double-layered membrane that consists of nuclear pores to regulate the transportation of substances such as RNA into and out of the nucleus. 
  • The chloroplast is also covered by a double membrane which is known as the chloroplast envelope.
  • So, the correct answer is 'Mitochondria, nucleus and chloroplast'.

Choose the number of diploid structures in the list given.
Pollen grains, nucellus, perisperm, endosperm, embryosac, megaspore

  1. Two

  2. Three

  3. Four

  4. One


Correct Option: A

Apospory is the development of an offspring from the __________________.

  1. Cell ofnucellus

  2. Synergids or antipodals

  3. Haploid female gamete

  4. Haploid microspore


Correct Option: A

Fluid contained inside the nucleus is called _______________________

  1. Protoplasm

  2. Nucleoplasm

  3. Cytosol

  4. Cytoplasm


Correct Option: B
Explanation:

The nucleus contains a viscous liquid called nucleoplasm. It contains chromosomes and nuclei. It is surrounded by a nuclear membrane and it helps in the exchange of material between nucleus and cytoplasm. So, the correct answer is option B.

Well defined nucleus is absent in

  1. Blue green algae

  2. Diatoms

  3. Algae

  4. Yeast


Correct Option: A
Explanation:

Algae are a very large and diverse group of eukaryotic organisms, ranging from the microscopic unicellular Chlorella and the diatoms to giant multicellular kelps, the large brown alga. Diatoms are algae (most commonly known as phytoplanktons) with secondary chloroplasts derived from an endosymbiotic red alga. Yeats is also a eukaryote belonging to the kingdom Fungi. However, the Blue-green algae or Cyanobacteria is the most primitive photosynthetic bacteria (prokaryotic- the absence of well-defined nucleus) cell which is quite small and usually unicellular, though they often grow in colonies large enough to see.
Hence, the correct answer is option A.

Read the following statements and write the appropriate term against each I

I control the functions of a cell. Who am I? 

  1. Neuron

  2. Nucleus

  3. Chloroplast

  4. Mitochondria


Correct Option: B
Explanation:

Neuron carries signals between the brain and various parts of the body. The chloroplast is a type of plastid, which produces green coloured pigment. The chloroplast is involved in carrying out photosynthesis. It gives a green colour to leaves. Mitochondria produce the energy currency, i.e., ATPs of the cell. It is also called as a powerhouse of the cell as it provides energy currency to a cell. 

Nucleus regulates all the cellular activities by controlling the enzymes required for cellular processes. Enzymes are proteins and protein synthesis is controlled by nucleus as mRNA required for protein synthesis is made from DNA, which is situated in the nucleus. Thus, the correct answer is option B.

Which cellular structure always show disappearance during mitosis?

  1. Nuclear membrane and nucleus

  2. Mitochondria

  3. Cell wall

  4. Chromosomes


Correct Option: A
Explanation:
  • The nuclear envelope needs to be broken apart so that the chromosomes can be found, aligned along the central plane of the cell, and then pulled apart. So during mitosis, the nuclear membrane disappears during mitosis 

So, the correct answer is 'Nuclear membrane and nucleus'

Which part of the cell controls one or more functions of the cell? 

  1. Nucleus

  2. Mitochondria

  3. Cell wall

  4. None of the above


Correct Option: A
Explanation:
The nucleus is the most important part of the cell which regulates all the cellular activities by controlling the enzymes required for cellular processes. Enzymes are proteins and protein synthesis is controlled by nucleus as mRNA required for protein synthesis is made from DNA which is situated in the nucleus. 

Which part of the cell helps the transfer of material from the nucleus to the cytoplasm?

  1. Nuclear pores

  2. Chromatin fibres

  3. DNA

  4. None of the above


Correct Option: A
Explanation:

DNA is a long polynucleotide strand, coiled to make chromatin fibres to fit into the cell. It also helps to prevent DNA damage. It is situated in the nucleus. 

In eukaryotic cells, the nucleus is bound by a double membrane envelope. This envelope of the nucleus is called as nuclear envelope. It possesses openings at certain intervals called as 'nuclear pore'. Nuclear pores are large protein complexes molecule in the nuclear envelope. It is involved in regulation and transfer of material from nucleus and cytoplasm. Thus, the correct answer is option A.