A mutation that involves the change of a single nucleotide base in the DNA sequence is called a:
A. Point mutation
B. Chromosomal deletion
C. Inversion
D. Frameshift mutation
Answer: Option A
Solution (By JKSSB Mock Tests)
A point mutation is a genetic mutation where a single nucleotide base is changed, inserted, or deleted from a sequence of DNA or RNA. The classic example is sickle cell anemia, caused by a single point mutation in the beta-globin gene, where adenine is replaced by thymine, changing the amino acid from glutamic acid to valine.
Consider the following statements about the cell membrane:
1. It is composed of a phospholipid bilayer.
2. It is fully permeable.
3. Proteins are embedded in the membrane.
Which of the above is/are correct?
Explanation:
Secondary consumers are carnivores or omnivores that eat primary consumers (herbivores). Example: frog eating grasshopper. Producers are autotrophs, primary consumers are herbivores, decomposers break down dead matter. Trophic levels represent energy transfer steps. Energy decreases at each higher level.
Explanation:
Theophrastus (c. 371–287 BCE), a student of Aristotle, is called the Father of Botany for his works 'Historia Plantarum' and 'De Causis Plantarum', in which he classified and described hundreds of plants. Aristotle is the Father of Zoology. Linnaeus developed binomial nomenclature. Darwin proposed natural selection. Theophrastus laid the early foundations of plant science.
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