Tag: cell-the basic unit of life

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Questions Related to cell-the basic unit of life

Multiple choice biology cell-the basic unit of life nucleus organelles in cell membranous and non-membranous organells

The nucleus is separated from the cytoplasm by ...........which is absent in .......... and present only in ......... The words filling the blanks are respectively

  1. Cell wall.bacteria and Amoeba

  2. Cell membrane , animals and prokaryotes

  3. Nuclear membrane, prokaryotes and eukaryotes

  4. Plasma membrane, eukaryotes and prokaryotes
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
  • The nucleus of a cell is separated from the cytoplasm by a double membrane known as the nuclear envelope.
  • Prokaryotes do not have genomic DNA that is concentrated and localized to a small area within the cell called nucleoid region, thus it is absent in them.
  • Whereas, a eukaryotic cell contains all the organelles and nucleus which is separated from the cytoplasm by the nuclear envelope.
  • The correct answer is OPTION C.
Multiple choice biology cell-the basic unit of life nucleus organelles in cell membranous and non-membranous organells

The thread like structure present in the nucleus are

  1. Nucleolus

  2. Genes

  3. Chromosomes

  4. Ribosomes
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The thread like structure present in the nucleus are called the chromosomes or the chromatin, when the degree of condensation is very less.

A. Nucleolus is the region on the chromosomes that codes for the ribosomal RNA. 
B. Genes are the segments of DNA that code for the proteins. These are located on the chromosomes.
C. The chromosomes are the thread like structures made up of DNA and proteins and are present in the DNA.
D. Ribosomes are the ribo-nucleoproteins present in the cytoplasm that take part in protein formation.
Hence, the correct answer is 'Chromosomes'

Multiple choice biology cell-the basic unit of life nucleus organelles in cell membranous and non-membranous organells

.......... could be found in both, the nucleus and the cytoplasm.

  1. Nucleolus

  2. Ribosomes

  3. RNA

  4. Both B and C
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

  • RNA is found everywhere- nucleus, nucleolus, mitochondria, chloroplasts, ribosomes, cytoplasm, etc. RNAs are 3 different types- mRNA, tRNA and rRNA. mRNA and tRNA are found in the cytoplasm and rRNA in the nucleus.
  • The ribosomes can be free within the cytoplasm of a cell or attached to the endoplasmic reticulum but do not present inside the nucleus. RNA and ribosomes act together resulting in the synthesis of proteins.

 Hence, the correct answer is option C.

Multiple choice biology cell-the basic unit of life nucleus organelles in cell membranous and non-membranous organells

Which of the following is correct : 

  1. cell of all living organisms have a nucleus.

  2. Both animal and plant cells have a well defined cell wall.

  3. In prokaryotes, there are no membrane bound organelles.

  4. Cells are formed de novo from abiotic materials.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation


  • The cell is the basic structural, functional, and biological unit of all known living organisms. A cell is the smallest unit of life. 
  • Cells are often called the "building blocks of life". 
  •  Cells are of two types: eukaryotic, which contain a nucleus, and prokaryotic, which do not. 
  • Prokaryotes are single-celled organisms, while eukaryotes can be either single-celled or multicellular. 
  • Hence, the cell of all living organisms have a nucleus is correct.
  • So, the correct answer is 'cell of all living organisms has a nucleus'.

Multiple choice biology cell-the basic unit of life nucleus organelles in cell membranous and non-membranous organells

The organelle of plant cell that does not contain functional DNA.

  1. Nucleus

  2. Chloroplast

  3. Mitochondria

  4. Peroxisome
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Within the nucleus is a small subspace known as the nucleolus. It is not bound by a membrane, so it is not an organelle. This space forms near the part of DNA with instructions for making ribosomes, the molecules responsible for making proteins.

Hence the correct option is A.

Multiple choice biology cell-the basic unit of life nucleus organelles in cell membranous and non-membranous organells

Number of chromosomes in nucellus is 24. Number of chromosomes in aleurone be.

  1. 30

  2. 24

  3. 36

  4. 19
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The nucellus is diploid (2n), so 2n = 24, which means the haploid number n = 12. The aleurone layer in seeds is triploid (3n) because it results from triple fusion. Thus, the number of chromosomes in the aleurone layer is 3 * 12 = 36.

Multiple choice biology cell-the basic unit of life nucleus organelles in cell membranous and non-membranous organells

The name of Hammerling is related with which of the following?

  1. Granum

  2. Discovery of RNA

  3. Discovery of DNA

  4. Experiment on Acetabularia
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Nucleus is a double membrane covered protoplasmic body that contains heredity information. With the help of grafting experiments on Acetabularia, Hammerling (1953) proved that nucleus is a storehouse of hereditary information.

Multiple choice biology cell-the basic unit of life nucleus organelles in cell membranous and non-membranous organells

Nucleus is a

  1. Single layered structure

  2. Three layered structure

  3. Four layered structure

  4. Two layered structure
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The nucleus is two layered structure, it is a membrane-enclosed structure found in eukaryotic cells. It contains most of the cell's genetic material. The function of the nucleus is to maintain the integrity of the genes and to control the activities of the cell by regulating gene expression.

Multiple choice biology cell-the basic unit of life nucleus organelles in cell membranous and non-membranous organells

The functional activities of a cell are controlled and directed by the

  1. Protoplasm

  2. Nucleus

  3. Mitochondria

  4. Endoplasmic reticulum
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The nucleus is the most important and the largest component of the cell. Nucleus regulates the four main functions of the cell which are protein synthesis, cell division, growth and differentiation are carried out by the nucleus. Nucleus regulates all these 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.