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 biology animal tissue muscular tissues muscle tissue muscle tissues

Among the following, which has the longest group of cells in the body?

  1. Connective

  2. Muscle

  3. Epidermal

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

Muscle tissue is the longest group of cells in the human body. These provide the structural framework to the body. They have contractile proteins which, contracts and relax to provide easy and flexible movements. Therefore, the correct answer is option B.

Multiple choice biology animal tissue muscular tissues muscle tissue muscle tissues

Which of organelle regulates the muscle contraction during internal movements?

  1. Ribosomes

  2. Golgi bodies

  3. Sarcoplasmic reticulum

  4. Both A and B
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
  • Sarcoplasmic reticulum is similar to endoplasmic reticulum present in other cells. It is present in sarcoplasm (cytoplasm of the muscle cell) of the muscle fiber (muscle cell).
  • The main function of the Sarcoplasmic reticulum is to store calcium ions (Ca2+).
  • When nerve signal reaches the neuromuscular junction it triggers the release of calcium from sarcoplasmic reticulum which in turn facilitates muscle contraction by binding to troponin.
  • Hence the organelle regulates the muscle contraction during internal movements is sarcoplasmic reticulum.
  • So, the correct answer is'Sarcoplasmic reticulum'.
Multiple choice biology animal tissue muscular tissues muscle tissue muscle tissues

Choose the correct answer from the alternatives givens.
In most ..........., cells secrete fibres of collagen and elastin:

  1. epithelial tissue

  2. muscle tissue

  3. connective tissue

  4. nervous tissue
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Glycoprotein, elastin, and collagen secretion by rat smooth muscle cells. Smooth muscle cells from rat heart secreted extracellular matrix components at high rates for many generations in culture. So the correct option is 'Muscle tissue'.

Multiple choice hmp shunt alternative to glycolysis carbohydrate metabolism respiration bio-chemistry

Phosphogluconate shunt occurs in

  1. Mitochondria

  2. Chloroplasts

  3. Cytoplasm

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

The reactions of hexose monophosphate shunt occur exclusively in the cytoplasm and is an additional pathway of glucose metabolism which starts with glucose-6-phosphate. About 10-25% of glucose is metabolised by this pathway. In plants, it occurs both in cytosol and plastids. This pathway involves both oxidative and nonoxidative steps. The oxidative steps generate NADPH and ribose-5-phosphate and then non-oxidative steps convert ribose-5-phosphate back into glucose-6-phosphate which can be further utilized for NADPH generations by means of oxidative steps. 

Thus, the correct answer is option C. 

Multiple choice bio-chemistry respiration in organisms glucose metabolism the need for energy in living organism respiratory function

The pentose phosphate pathway (PPP) of most organisms take place in

  1. Mitochondria

  2. Cytoplasm

  3. Chloroplast, peroxisome and mitochondrion

  4. Chloroplast, glyoxysome and mitochondrion

  5. Chloroplast, lysosome and mitochondrion
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Pentose phosphate pathway is also called as phosphogluconate pathway or Hexose Monophosphate Shunt (HMP Shunt). It occurs in most organisms in cytoplasm. It results in generation of NADPH, ribose-5-phosphate (R5P) and erythrose 4-phosphate (E4P). R5P is precursor for the synthesis of nucleotides. E4P is involved in the synthesis of aromatic amino acids. 

Thus, the correct answer is option B.

Multiple choice zoology applications of biotechnology cloning process of cloning gene cloning

Population of cells derived from a single parent cell is called

  1. Symmetrical cell

  2. Diploid

  3. Haploid

  4. Clone
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
Clone are cells or organism that is genetically identical to the original cell or organism from which it is derived. Many unicellular organisms, such as bacteria and yeasts, are clones of parent cells generated by either binary fission or budding. The body cells of plants and animals are clones ultimately derived from the mitosis (cell reproduction) of a single fertilized egg. More narrowly, a clone can be defined as an individual organism that was grown from a single body cell of its parent and that is genetically identical to it.
So the correct option is 'clone'.
Multiple choice zoology nervous system of man major divisions of nervous system introduction to control and coordination neurons and synapses

Largest cell in body is

  1. Lymph

  2. Osteoctyte

  3. Neuron

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

Lymph is the fluid having the same composition as tissue fluid and is carried in lymph vessels. Osteocytes, the bone cells are the longest-lived cells. Chromatophores with black pigment present in certain parts of brain and retina are one of the largest cells at maturity; however, not it does not hold true for all chromatophores. Neurons are the largest cells that can be several feet long. Each neuron consists of the dendrite, axon and soma. Thus, the correct answer is option C.

Multiple choice biology locomotion and movements introduction to locomotion skeleton and joints movement in animals

The cells of human body exhibits type of movement is

  1. Amoeboid

  2. Ciliary

  3. Muscular

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

Movement is a characteristic feature of living organisms. The different types of movement exhibited by cells of the human body are: 

  • Amoeboid movement: Leucocytes present in the blood show amoeboid movement. 
  • Ciliary movement: Reproductive cells such as sperms and ova show ciliary movement.
  •  Muscular movements:  Muscle tissue found inside of the heart, digestive organs, and blood vessels serve to move substances throughout the body. Hence, The cells of the human body exhibits type of movement are Amoeboid, Ciliary and Muscular.
So, the correct answer is 'All of the above'.

Multiple choice biology digestion and absorption digestive system- glands mouth and buccal cavity digestive glands

The cells constituting the walls of the blood capillaries are known as

  1. Parietal cells

  2. Haemocytes

  3. Chondrocytes

  4. Endothelial cells
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The endothelium is a type of epithelium that lines the interior surface of organs. It is present in the inner lining of blood vessels and lymphatic vessels, forming an interface between circulating blood or lymph in the lumen and the rest of the vessel wall. It is a thin layer of simple squamous cells called endothelial cells. Whereas hemocyte is a blood cell, especially in an invertebrate, parietal cells (also known as oxyntic or delomorphous cells), are the epithelial cells that secrete hydrochloric acid (HCl) and intrinsic factor and chondrocyte is a cell that has secreted the matrix of cartilage and become embedded in it. Thus, option D is correct.

Multiple choice bio-chemistry lipids derived lipids biomolecules: chemical constituents of living cells cell membrane

Beta-oxidation mainly takes place in _________.

  1. Cytoplasm

  2. Mitochondria

  3. Golgi bodies

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

In biochemistry and metabolism, beta-oxidation is the catabolic process by which fatty acid molecules are broken down in the cytosol in prokaryotes and in the mitochondria in eukaryotes to generate acetyl-CoA, which enters the citric acid cycle, and NADH and FADH2, which are co-enzymes used in the electron transport.

Multiple choice bio-chemistry lipids derived lipids biomolecules: chemical constituents of living cells cell membrane

In the fluid mosaic membrane model, the phospholipid bilayer

  1. Is sandwiched between two protein layers

  2. Is covered by a single protein layer

  3. Has proteins embedded in it

  4. Lies on top of a single protein layer
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

In the fluid mosaic model, the phospholipid bilayer has integrated as well as peripheral proteins embedded in it. The integrated proteins are found on the inside and span across the bilayer, while the peripheral proteins are found at the periphery of the lipid layers.

So the correct answer is 'has proteins embedded in it'.

Multiple choice bio-chemistry lipids derived lipids biomolecules: chemical constituents of living cells cell membrane

Two important processes in a cell, which take place outside the membrane bound organelles, are

  1. Enzyme synthesis and DNA replication

  2. Nucleotide synthesis and mutation

  3. Fatty acid synthesis and spindle assembly

  4. Glycolysis and photophosphorylation
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
The process of fatty acid synthesis takes place in the cytoplasm and not in a membrane-bound organelle. Also, spindle assembly takes place in the centrioles which also lack a membrane.

So, the correct answer is 'fatty acid synthesis and spindle assembly'.