The process by which a bacterial cell takes up DNA from its environment is:
A. Conjugation
B. Transformation
C. Lysogeny
D. Transduction
Answer: Option B
Solution (By JKSSB Mock Tests)
Transformation is the direct uptake and incorporation of naked DNA from the surroundings by a bacterium. Conjugation is DNA transfer via pilus, transduction via phage, lysogeny is phage DNA integration.
Explanation:
Smooth endoplasmic reticulum (SER) lacks ribosomes and is involved in synthesis of lipids, steroid hormones, and detoxification of drugs and toxins via cytochrome P450 enzymes. Rough ER is for protein synthesis, Golgi for packaging, lysosomes for digestion. SER is abundant in liver and gonadal cells.
Explanation:
Hematopoiesis is the production of formed elements of blood (red cells, white cells, platelets) from hematopoietic stem cells in the bone marrow. Hemolysis is RBC destruction, hemostasis is stopping bleeding, hematuria is blood in urine. Erythropoietin stimulates RBC production.
Explanation:
Meselson and Stahl proved that after replication, each daughter DNA contains one parental and one newly synthesized strand. R exactly explains semiconservative.
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