Which of the following statements about biotechnology is correct?
A. Restriction enzymes join DNA fragments.
B. Bt cotton is resistant to all pesticides.
C. Plasmids are used as vectors because they can replicate independently.
D. Tissue culture produces genetically diverse plants.
Answer: Option C
Solution (By JKExamLibrary)
Plasmids have an origin of replication, making them effective cloning vectors. Restriction enzymes cut DNA, tissue culture produces clones, Bt cotton targets specific insects.
Explanation:
Hemoglobin is a red, iron-containing protein in red blood cells (erythrocytes) that reversibly binds oxygen to form oxyhemoglobin. Each molecule has four heme groups, each binding one O₂ molecule. Hemocyanin (copper-based) is found in some invertebrates. Myoglobin stores oxygen in muscles. Cytochromes are electron carriers in respiration. Hemoglobin also transports CO₂ as carbaminohemoglobin.
Explanation:
Monocot stems have numerous vascular bundles scattered in the ground tissue. They are closed (lack cambium), collateral, and hence do not undergo secondary growth. Dicot stems have vascular bundles arranged in a ring, open (with cambium) allowing secondary growth. Radial vascular bundles are characteristic of roots. Scattered bundles are a key identifying feature of monocots.
Explanation:
The nucleolus makes rRNA and assembles ribosomal subunits. Nucleus has a double membrane, is present in eukaryotes, and is the site of DNA replication.
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