This set of Cell Biology Multiple Choice Questions & Answers (MCQs) focuses on “Chloroplast Structure and Function – Chloroplast and Photosynthetic Pigments”.
1. Who first discovered chloroplast?
a) J Rhodin
b) Robert Porter
c) Camillo Golgi
d) Konstantin Mereschkowski
Explanation: Chloroplast are small cell organelles found in both eukaryotic and some prokaryotic photosynthetic organisms. They were first discovered by Konstantin Mereschkowski in 1905.
2. What is the diameter of a chloroplast?
a) 1 – 2 micrometer
b) 2 – 4 micrometer
c) 4 – 6 micrometer
d) 6 – 10 micrometer
Explanation: Chloroplasts are generally 4 – 6 micrometer in diameter and 2 – 4 micrometer in thickness. These chloroplasts are round, oval and disc shaped organelles.
3. The mass of chloroplast DNA is __________
a) 10 – 15 million daltons
b) 50 – 100 million daltons
c) 80 – 130 million daltons
d) 25 – 125 million daltons
Explanation: The chloroplasts have their own DNA, which is circular in shape that forms a ring like structure. A single chloroplast DNA has a mass of about 80 – 130 million daltons.
4. The number of chloroplasts found in Arabidopsis thaliana is _____________
Explanation: Arabidopsis thaliana commonly known as mouse-ear cress has around 100 chloroplasts in each cell. The number of chloroplasts in each organism differ from species to species depending on the need of energy from photosynthesis.
Explanation: Thylakoids resemble the structure of a coin, a stack of thylakoids looks like a stack of coins known as grana. The lumen is a connection between two or more grana.
6. The sunlight is captured by the membrane of thylakoids.
Explanation: The membrane of thylakoids is responsible for photosynthesis. They entrap the solar energy and provide it for the photosynthesis.
7. Which pigment is responsible for the process of sunlight?
a) Chlorophyll a
b) Chlorophyll b
Explanation: Chlorophyll a is the pigment, which primarily helps in photosynthesis. Xanthophyll and Anthocyanin are the pigments responsible for yellow and blue colour in plants respectively.
8. Which pigment constitutes majorly in absorbing sunlight for photosynthesis?
a) Chlorophyll a
b) Chlorophyll b
Explanation: Chlorophyll b is a pigment, which is yellow in colour. This pigment is responsible for the vast absorption of sunlight. It is present in the light absorbing antenna of the plants.
9. Which of the following organisms has photosynthetic pigments in it?
Explanation: The spirulina, which belongs to the community of cyanobacteria, commonly known as blue green algae, has photosynthetic pigments in it. They predominantly contain chlorophyll a.
10. What is the chemical formula of chlorophyll a?
Explanation: The chlorophyll a contains a magnesium ion complex, which forms a ring structure called the Chlorin ring. It has a molar mass of 893.51 g•mol−1.
11. Chloroplast divide by binary fission.
Explanation: Chloroplasts cannot be synthesized by the cell itself. They have their own DNA and it divides by binary fission process like prokaryotes.
12. What disease is caused by the dysfunction of chloroplast?
a) Leaf spot
b) Blight spot
c) Leaf variegation
d) Powdery mildew
Explanation: Leaf variegation is caused by the deficiency of chloroplast due to mutation. Blight spot, Leaf spot and Powdery mildew are caused by fungi.
Sanfoundry Global Education & Learning Series – Cell Biology.
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