Tag: cell-the basic unit of life

Questions Related to cell-the basic unit of life

Which one of the following contains the genetic material of a eukaryotic cell?

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

  1. Golgi apparatus

  2. Mitochondria

  3. Nucleolus

  4. Nucleus

Show answer
Correct Option: D
Explanation:

Golgi apparatus is an organelle present in the cell and structurally possess series of compartments. Golgi apparatus has the main function of modifying, sorting and packaging the proteins which are synthesized by cells. Golgi bodies are also involved in the transport of lipid molecules across the cell. Golgi bodies also create lysosomes.  
Mitochondria produce the energy in the form of ATP of the cell. It consists its own DNA and called as mitochondrial DNA and not the DNA of the cell.
The nucleolus is the largest structure present in the nucleus. Ribosome synthesis and assemblage occurs in nucleolus region. The nucleus is bound with the double membrane in a eukaryotic cell in which most of the genetic material is present. The genetic material contains DNA and RNA. Thus, the correct answer is option D.

Function of Nuclear membrane is 

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

  1. Nuclear membrane porous and the inside of the nucleus.

  2. It allows the movement of materials between the cytoplasm and the inside of the nucleus

  3. Both A and B

  4. None of these

Show answer
Correct Option: C
Explanation:

Nuclear membrane is also porous and allows the movement of materials between the cytoplasm and the inside of the nucleus.

The nucleus has a double layered covering called as

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

  1. Cell membrane

  2. Cytoplasmic membrane

  3. Nuclear membrane

  4. Capsule

Show answer
Correct Option: C
Explanation:

A eukaryotic cell has a nucleus bounded by a double wall membrane structure known as a nuclear membrane. The nuclear membrane is a discontinuous membrane having nuclear pores, which act as a protein channel for regulating the exchange of materials between cytoplasm and nucleoplasm. The gap between the inner and outer membrane is known as perinuclear space.

................ is present inside the nucleus of a cell.

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

  1. Mitochondrion

  2. Ribosome

  3. Endoplasmic reticulum

  4. Chromatin

  5. Centriole

Show answer
Correct Option: D
Explanation:

Chromatin is a complex of DNA and proteins that form chromosomes within the nucleus of eukaryotic cells. Nuclear DNA does not appear in free linear strands. 

It is highly condensed and wrapped around nuclear proteins in order to fit inside the nucleus. 
So option D is correct. 

The transmission of hereditary characteristics is carried out by ___________.

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

  1. Nucleus

  2. Endoplasmic reticulum

  3. Ribosome

  4. Golgi apparatus

  5. Lysosome

Show answer
Correct Option: A
Explanation:

A- As nucleus contains the genetic material responsible for hereditery. 

Cell nucleus is the site for

I. RNA synthesis 
II. Proteins synthesis 
III. DNA synthesis

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

  1. I only

  2. II only

  3. III only

  4. I and III only

  5. I, II and III

Show answer
Correct Option: D
Explanation:

The nucleus is the important structure of the cell and fully enclosed in a nuclear membrane. It contains the cells' genetic material organized as DNA and variety of proteins to form chromosomes. This is major site for cell reproduction. The genes are first transcribed, where DNA is read by RNA polymerase to produce messenger RNA (mRNA). The nucleus is therefore the site of RNA and DNA synthesis. Whereas protein is synthesized from the mRNA in the cytoplasm. Thus, the correct answer is option D.

The nucleus possessed the ability to control phenotype was first determined by

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

  1. Experiments with radiolabelled phages

  2. Experiments with bacteria that identified DNA polymerase

  3. Transformation experiments with Streptococcus pneumoniae

  4. Identification of restriction endonucleases

  5. Grafting experiments with Acetabularia

Show answer
Correct Option: E
Explanation:

Acetabularia consists of a rootlike holdfast, a long, cylindrical stalk; and a cuplike cap. The nucleus is present in the holdfast. Acetabularia exhibits regeneration of the cap after any injury. A. mediterranea has a smooth cap and A. crenulata, has a cap with fingerlike projections. Danish biologist J. Hämmerling and Belgian biologist J. Brachet performed grafting experiment on above mentioned species and showed that type of caps that regenerated were determined by the type of the donor species of the holdfasts, not by those donating the stalks. It was concluded, that nucleus in the holdfast of Acetabularia controls the shape of the caps. The correct answer is E.

All of the following organelles are associated with an endomembrane except

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

  1. Nucleus

  2. Vesicles

  3. Golgi apparatus

  4. Endoplasmic reticulum

  5. Plasma membrane

Show answer
Correct Option: A
Explanation:

The eukaryotic endomembrane system has a nuclear membrane, endoplasmic reticulum, Golgi apparatus, plasma membrane and various small vesicles which are constantly reorganized and serve to segregate specific metabolic processes and to provide surfaces for enzyme-catalyzed reactions.
So, the correct answer is option A.

Abhi conducted an experiment to investigate what would happen when different cell organelles of a balsam plant leaf are removed. The results are recorded in the table given.

Cell parts Out comes
P The cell cannot function properly.
Q Iodine solution remains yellowish brown.
R The cell cannot control the entry and exit of the substances.
S The cell loses its regular shape

Identify the cell parts P, Q, R and S.

(P) (Q) (R) (S)
(A) Nucleus Chloroplast Cell wall Cytoplasm
(B) Cytoplasm Chloroplast Nucleus Cell membrane
(C) Nucleus Chloroplast Cell membrane Cell wall
(D) Nucleus Chloroplast Cell wall Cell membrane
biology cell-the basic unit of life nucleus organelles in cell membranous and non-membranous organells

  1. A

  2. B

  3. C

  4. D

Show answer
Correct Option: C
Explanation:

The label P is the nucleus is the controlling centre of the cell. All the activities of the cell are controlled and regulated by the nucleus and the cell cannot function properly in the absence of this organelle. 
The label Q is the chloroplast which is responsible for making food in the form of starch which turns the iodine solution to bluish black. In the absence of chloroplast, the solution remains yellowish brown.
The label R is the cell membrane which controls the entry and the exit of the molecules.
The label S refers to the cell wall which maintains the shape of the cell.
Thus, the correct answer is option C. 

Pick the odd one out giving the suitable reasons.

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

  1. Nucleus

  2. Nucleolus

  3. Chromosome

  4. Ribosome

Show answer
Correct Option: D
Explanation:
Ribosomes and chromosomes. A ribosome is a component of cells that synthesizes protein chains.