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

The tapetal cells are

  1. uninucleate

  2. anucleate

  3. multinucletae

  4. dikaryotic

  5. -
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Tapetal cells are multinucleate as these contain multiple nuclei in them.

Multiple choice

Metastasis is the process of:

  1. Excessive cell proliferation

  2. Transformation of a benign tumour into a malignant tumour

  3. Movement of cancerous cells from one site to another site in the body

  4. Transformation of a normal cell into a tumourous cell
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Metastasis refers to the spread of cancer cells from the primary tumor site to distant organs or tissues through the bloodstream or lymphatic system. This process is what distinguishes malignant cancers from benign tumors and is a major factor in cancer staging and treatment decisions.

Multiple choice

Which a microtubule motor protein carries membrane enclosed organelles toward the plus end of microtubules?

  1. Cytoplasmic dyneins

  2. Axonemal Dyneins

  3. Kinesin

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

Kinesin are plus end directed microtubule protein that uses a microtubule track along which it tends to walk. They are vital to movement of chromosomes during mitosis and are also responsible for shuttling membrane bound organelles (mitochondria, Golgi bodies, and vesicles within eukaryotic cells. 

Multiple choice

Besides the nucleus, the DNA is also present in the

  1. golgi apparatus

  2. ribosome

  3. mitochondria

  4. vacuole

Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Mitochondria contain their own circular DNA molecule (mtDNA), separate from nuclear DNA. This mitochondrial DNA encodes proteins essential for the organelle's role in ATP production. The other organelles listed (golgi apparatus, ribosomes, vacuoles) do not contain DNA.

Multiple choice

Amitosis usually occurs in

  1. eukaryotic cells

  2. prokaryotic cells

  3. viruses

  4. All of the above
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

It is the simplest form of cell division without forming chromosomes and is usually seen in bacteria.

Multiple choice

Krebs cycle takes place in

  1. chloroplast

  2. ribosome

  3. mitochondria

  4. endoplasmic reticulum

  5. cytosol
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Krebs cycle occurs in the mitochondria.

Multiple choice

Which of the following organelles would you select, if the given statement is considered to be an absolute fact? “More the levels of intracellular IP3 (inositol Triphosphate), more is the efflux of Ca++ from its membranes in the cytoplasm.”

  1. Lysosomes

  2. Mitochondria

  3. Peroxisomes

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

The Ca++ channel in the membrane of endoplasmic reticulum is also an IP3 receptor and therefore, an increase in IP3 will enhance the activity of the channel, resulting in increased efflux of ions.

Multiple choice

Typical brush border of cells is seen in

  1. proximal convoluted tubules

  2. loop of Henle

  3. distal convoluted tubules

  4. pelvis

Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Typical brush border of cells is seen in proximal convoluted tubules. The microvilli greatly increase the luminal surface area of the cells, presumably facilitating their resorptive function as well as putative flow sensing within the lumen.

Multiple choice

Which of the following observations most strongly supports the view that mitochondrial membranes have Electron Transport System (ETS) enzymes?

  1. Mitochondria have a property to concentrate in the locomotive cells.

  2. Mitochondria have a folded inner membrane structure.

  3. Disruption of mitochondrial membrane yields out fragments that are able to synthesise ATP.

  4. A contractile protein capable of utilising ATP is obtained from mitochondria.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

If fragments of the mitochondrial membranes are able to synthesise ATP, it is proved that the ATP synthesising enzymes are localised in the inter-membranous space. ATP synthesis is achieved only by the path of Electron Transport Chain, so the enzymes involved in the chain are bound to be located in there.

Multiple choice

“Intussusception” is a well-known physical property of primary cell wall. It is characterised as

  1. hardening of cell wall

  2. deposition of cell wall material from outside as layers

  3. deposition of cell wall material from inside to cause growth

  4. None of these
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Intussusception is the the expansion of the cell wall in plants as a result of the introduction of new molecules of cellulose and protopectin into the already formed wall. Instussusception is a well-known term as a medical condition of instestines where a part of the intestine has invaginated into another section of intestine, similar to the way in which the parts of a collapsible telescope slide into one another.