The sequence of progressive, predictable changes in the species composition of a community over time is called:
A. Eutrophication
B. Stratification
C. Biological magnification
D. Ecological succession
Answer: Option D
Solution (By JKSSB Mock Tests)
Ecological succession is the gradual and predictable process of change in the species composition of an ecological community over time. It occurs after a disturbance (secondary succession) or on a newly formed, lifeless substrate (primary succession). The final, stable community that is in near equilibrium with the environment is called the climax community. The entire sequence of communities is called a sere.
Explanation:
Cardiac muscle is striated, branched, and involuntary, with intercalated discs containing gap junctions for synchronized contraction. It is unique to the heart wall. Smooth muscle is non-striated and involuntary in visceral organs, skeletal muscle is striated and voluntary. Cardiac muscle exhibits autorhythmicity.
Explanation:
Blood group O lacks A and B antigens on red cells but contains both anti-A and anti-B antibodies in plasma. This makes it the universal donor for packed red cells but dangerous plasma donor. Group AB has no antibodies. So, the presence of both antibodies is correct.
Explanation:
The Ti (tumor-inducing) plasmid from Agrobacterium tumefaciens is a natural plant genetic engineer. It transfers T-DNA into the plant genome, making it an effective vector for introducing foreign genes in plant genetic engineering. pBR322 is a common E. coli cloning vector. Bacteriophage lambda and cosmids are used in animal/bacterial systems. Ti plasmid has revolutionized GM crop development.
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