All Free Biology MCQs with Answers

1831. In golgi apparatus the maturing face is____________?

• A. Biconcave
• B. Convex
• C. Spherical
• D. Concave

Explanation: The trans face of the Golgi apparatus is the maturing or shipping face and is generally concave, with vesicles leaving it toward their destinations. The likely mistake is choosing convex, which describes the cis or forming face that receives vesicles from the endoplasmic reticulum.

1832. Proteins and lipids are converted into glycolipids and glycoproteins by adding carbohydrates by___________?

• A. Ribosomes
• B. Cytoplasm
• C. Golgi apparatus
• D. Endoplasmic reticulum

Explanation: The Golgi apparatus modifies proteins and lipids and adds carbohydrate groups to form glycoproteins and glycolipids. A student may choose the endoplasmic reticulum because it makes many proteins and lipids, but the carbohydrate modification and final processing are mainly Golgi functions.

1833. Amoeboid movements and movement of cyclosis is due to_________?

• A. Microfilaments
• B. Microtubules
• C. Intermediate filaments
• D. Cytoskeleton

Explanation: Microfilaments made mainly of actin produce amoeboid movement and help generate cytoplasmic streaming, also called cyclosis, through interactions with myosin. The likely alternative is microtubules because they support cilia and flagella, but microtubules are not the main structures responsible for these movements.

1834. Ribonucleo-protein particles are the name of__________?

• A. DNA
• B. Nucleus
• C. Eukaryotic ribosomes
• D. RNA

Explanation: Eukaryotic ribosomes are ribonucleoprotein particles because they contain ribosomal RNA combined with ribosomal proteins. A student may choose RNA because it is a major component, but RNA alone is not a ribonucleoprotein particle; the complete particle is the ribosome.

1835. The type of plastids which help in pollination is_________?

• A. Chromoplasts
• B. Leucoplasts
• C. Chloroplasts
• D. All of these

Explanation: Chromoplasts contain coloured pigments that make flowers and fruits conspicuous, helping attract pollinators and seed-dispersing animals. A student may choose chloroplasts because they are also plastids and contain pigment, but chlorophyll mainly captures light for photosynthesis rather than attracting pollinators.

1836. Which of the following combination is an example of self replicating organelles?

• A. Mitochondria Ribosomes
• B. Mitochondria Nucleus
• C. Mitochondria Chloroplast
• D. Mitochondria Vacuole

Explanation: Mitochondria and chloroplasts contain their own DNA and ribosomes, allowing them to produce some proteins and replicate independently within the cell. This semi-autonomous nature supports the endosymbiotic theory. Ribosomes do not self-replicate as organelles, and vacuoles lack their own genetic system, so option a is a common mistake.

1837. On which of the following component of chloroplast chlorophyll is arranged?

• A. Cell membrane
• B. Matrix
• C. Thylakoids
• D. Stroma

Explanation: Chlorophyll is embedded in the photosynthetic membranes of thylakoids, where it captures light energy for the light-dependent reactions. The stroma contains enzymes for carbon fixation but does not arrange the chlorophyll molecules into the light-absorbing membrane system. A student may choose stroma because it is also a major chloroplast component, but chlorophyll is associated with thylakoid membranes.

1838. Which of the following is not present in mitochondria?

• A. Enzymes
• B. Co-enzymes
• C. Ribosomes
• D. Thylakoids

Explanation: Mitochondria contain respiratory enzymes, coenzymes and their own ribosomes, reflecting their bacterial evolutionary origin. Thylakoids are flattened photosynthetic membranes found in chloroplasts, not mitochondria. Students may select ribosomes because mitochondria are often described mainly as energy-producing organelles, but mitochondrial ribosomes are present.

1839. Ribosomes are assembled in__________?

• A. Nucleolus
• B. Nucleus
• C. DNA
• D. RNA

Explanation: The nucleolus makes ribosomal RNA and combines it with ribosomal proteins to assemble the two ribosomal subunits. These subunits then leave the nucleus through nuclear pores and function in the cytoplasm. The likely distractor is nucleus because the nucleolus lies inside it, but the specialised site of ribosome assembly is the nucleolus.

1840. Of the following which one is not the characteristic of mitochondria?

• A. It contains F1 particles
• B. It is involved in the synthesis of protein
• C. It is a self replicating organelle
• D. Number of mitochondria is constant

Explanation: Mitochondria contain F1 particles, possess their own DNA and ribosomes, and can synthesize some proteins and replicate independently. Their number is not constant because cells with high energy demands generally contain more mitochondria; students may choose b by wrongly assuming mitochondria only produce ATP and cannot synthesize protein.