Biology · Science General

Cell Biology and Structure

3,062 Questions

Cell biology focuses on the structure and function of cellular organelles. Key topics include cellular respiration, DNA inheritance, and energy production. These fundamental biology concepts are crucial for medical entrance and state service examinations.

Cell organelles functionsCellular respiration sitesDNA and ribosomesAnimal cell structurePlant cell components

Cell Biology and Structure Questions

Multiple choice 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

Which of the following sets of cell organelles contain DNA?

  1. Mitochondria, peroxysorne

  2. Plasma membrane, ribosome

  3. Mitochondria, chloroplast

  4. Chloroplast, dictyosome
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

A eukaryotic cell has DNA in nucleus as well as cell organelles like mitochondria and chloroplasts. The DNA in cell organelles resembles prokaryotic DNA. The organelle DNA is present as a circular molecule while the DNA in nucleus is organised as linear structures.

Multiple choice 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

DNA is present in

  1. Chromosomes and dictyosomes

  2. Chloroplast and lysosomes

  3. Mitochondria and chloroplasts

  4. Mitochondria and endoplasmic reticulum
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

DNA is a long polymer made from repeating units called as nucleotides. DNA is found in mitochondria, plastid & nucleolus. Eukaryotic organisms like animals, plants, fungi, and protists store most of their DNA inside the cell nucleus and some of their DNA in organelles, such as mitochondria or chloroplasts. In contrast, prokaryotes like bacteria and archaea store their DNA only in the cytoplasm. 

Multiple choice 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

Extra nuclear DNA is found in

  1. Lysosome and chloroplast

  2. Chloroplast and mitochondria

  3. Mitochondria and lysosome

  4. Golgi and endoplasmic reticulum
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Extrachromosomal DNA is found in chloroplast and mitochondria. Extrachromosomal DNA is any DNA that is found outside of the nucleus of a cell. It is also referred to as extranuclear DNA  or cytoplasmic DNA. Most DNA in an individual genome is found in chromosomes. Extrachromosomal DNA is often used in research of replication because it is easy to identify and isolate.

Multiple choice 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

Which of the following is not common in chloroplasts and mitochondria?

  1. Both are present in animal cells.

  2. Both contains their own genetic material.

  3. Both are present in eukaryotic cells.

  4. Both are present in plant cells.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Extrachromosomal DNA is any DNA that is found outside of the nucleus of a cell. It is also referred to as extranuclear DNA or cytoplasmic DNA. This extra chromosomal DNA is present in both mitochondria and chloroplast. Chloroplast and mitochondria are present in the plant cell but chloroplast is absent in the animal cell. They both are present in eukaryotic cells.

Multiple choice 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

Select the wrong statement from the following.

  1. Both chloroplasts and mitochondria contain an inner and outer membrane.

  2. Both chloroplasts and mitochondria have an internal compartment, the thylakoid space bounded by the thylakoid membrane.

  3. Both chloroplasts and mitochondria contain DNA.

  4. The chloroplasts are generally much larger than mitochondria.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Option b is incorrect because a  thylakoid is a membrane-bound compartment inside chloroplasts and cyanobacteria and not present in the mitochondrion. They are the site of the light-dependent reactions of photosynthesis. Thylakoids consist of a thylakoid membrane surrounding a thylakoid lumen. Chloroplast thylakoids frequently form stacks of disks referred to as grana. Grana are connected by intergranal or stroma thylakoids, which join granum stacks together as a single functional compartment.

Multiple choice 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

Autonomic genome system is present in

  1. Ribosomes and chloroplasts

  2. Mitochondria and ribosomes

  3. Mitochondria and chloroplasts

  4. Golgi bodies and mitochondria
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

According to the endosymbiotic theory about origin of chloroplast and mitochondria, both of these cell organelles were independent organisms that became lodged inside a eukaryotic cell during evolution. 

As both chloroplast and mitochondria were once upon a time independent organisms they have their own genetic material as well as protein synthesis machinery. 

Thus, they have their own autonomous genome system.

Multiple choice 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

Which of the following organelles contain circular DNA.

  1. Peroxisomes and mitochondria

  2. Mitochondria and Glgicomplex

  3. Chloroplasts and Lysosomes

  4. Mitochondria and chloroplast
Reveal answer Fill a bubble to check yourself
D Correct answer
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.
Multiple choice 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

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

  1. 1

  2. 2

  3. 3

  4. 4
Reveal answer Fill a bubble to check yourself
B Correct answer
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'.

Multiple choice 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

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
Reveal answer Fill a bubble to check yourself
B Correct answer
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'.
Multiple choice botany living world of animals number and shape of cells unicellular and multicellular organisms diversity and classification in animals cell parameters

Efficient large-sized cells are

  1. Elongated

  2. Elongated or branched

  3. With large surface area

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

  • Generally, cells are small so they can have an efficient surface area to volume ratio. Cells are so small so they can diffuse faster and all their processes will be a lot faster because of the smaller size of the cell.
  • For the large sized cells to become Efficient the cells must be elongated in order to have an efficient surface area to volume ratio.
  • Hence efficient large-sized cells are elongated.
  • So, the correct answer is 'Elongated'.

    • Multiple choice botany cell theory, cell specialization, and cell replacement number and shape of cells unicellular and multicellular organisms diversity and classification in animals

    Which one is enucleated?

    1. Squamous epithelial cells

    2. Mature leucocyte of man

    3. Mature erythrocyte of frog

    4. Mature erythrocyte of man

    5. Osteocyte in man
    Reveal answer Fill a bubble to check yourself
    D Correct answer
    Explanation

    • Enucleation is the phenomenon in which the nucleus is removed. Enucleation occurs roughly when the cell has reached maturity.
    • Red blood cells or Erythrocytes are initially produced in the bone marrow with a nucleus. They then undergo a process known as enucleation.
    • Enucleation allows the red blood cell to contain more hemoglobin and therefore, carry more oxygen molecules. It also allows the cell to have its distinctive bi-concave shape which aids diffusion. This shape would not be possible if the cell had a nucleus in the way. Hence mature erythrocyte of man is enucleated.
    • So, the correct answer is 'Mature erythrocyte of man'.

    Multiple choice botany cell theory, cell specialization, and cell replacement number and shape of cells unicellular and multicellular organisms diversity and classification in animals

    Growth at cellular level, is principally a consequence of increase in the amount of

    1. Protoplasm

    2. DNA

    3. Cell wall

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

    Protoplasm comprises of cytoplasm, nucleus and other cell organelles. Growth at cellular level includes increase in size of nucleus and other cell organelles. The growth at cellular level is a result of increase in amount of protoplasm.

    Thus, the correct answer is 'Protoplasm.'

    Multiple choice botany cell theory, cell specialization, and cell replacement number and shape of cells unicellular and multicellular organisms diversity and classification in animals

    Refer to the following table for your possible answer.

    Cell types analysed Average mass of DNA/cell (x $10^{-11}$g)
    X $0.00$
    Y $3.35$
    Kidney $6.70$
    Lung $6.70$

    What is the correct identify of cell type X and Y?

    1. X-sperm cell, Y-liver cell

    2. X-liver cell, Y-smooth muscle cell

    3. X-smooth muscle cell, Y-mature red blood cell

    4. X-mature red blood cell, Y-sperm cell
    Reveal answer Fill a bubble to check yourself
    A Correct answer
    Multiple choice botany cell theory, cell specialization, and cell replacement number and shape of cells unicellular and multicellular organisms diversity and classification in animals

    Smaller cells have

    1. Small surface area per volume ratio.

    2. Large surface area per volume ratio.

    3. Slow exchange rate of nutrients.

    4. None of the above.
    Reveal answer Fill a bubble to check yourself
    B Correct answer
    Explanation

    Surface area to the volume ratio gets smaller as the cell gets larger. Thus, if the cell grows beyond a certain limit, not enough material will be able to cross the membrane fast enough to accommodate the increased cellular volume. Small cells, therefore, have a large surface area to volume ratio. The large surface area to volume ratio of small cells makes the transport of substances into and out of cells extremely efficient.