101. Which of the following is correct regarding plant life span and reproductive behaviour:
(a) monocarpic plants are always annual
(b) all perennial plants are polycarpic
(c) some perennial plants may exhibit monocarpic behaviour
(d) biennial plants are polycarpic as they live for two years
Answer:
(c) some perennial plants may exhibit monocarpic behaviour
Explanation:
While most perennial plants are polycarpic (flowering multiple times), certain perennials like some species of bamboo and Agave only flower once in their lifetime and then die, making them monocarpic.
102. The occurrence of dwarf phenotype in the $F_2$ generation which can be inferred about inheritance pattern as:
(a) expression of recessive trait
(b) blending inheritance
(c) loss of dominant trait
(d) mutation
Answer:
(a) expression of recessive trait
Explanation:
In Mendelian genetics, a dwarf phenotype reappearing in the $F_2$ generation indicates that it is a recessive trait that was masked in the $F_1$ generation but expressed when homozygous recessive alleles combine.
103. Root hairs originate from:
(a) root cap
(b) region of meristematic activity
(c) region of elongation
(d) region of maturation of a plant root
Answer:
(d) region of maturation of a plant root
Explanation:
Root hairs are unicellular tubular extensions of the epidermis that exclusively develop in the region of maturation (or differentiation) of the root.
104. The naming system of binomial nomenclature was given by:
(a) Ernst Mayr
(b) Charles Darwin
(c) Carolus Linnaeus
(d) R.H. Whittaker
Answer:
(c) Carolus Linnaeus
Explanation:
The formalized system of naming organisms using two Latin terms (genus and species), known as binomial nomenclature, was developed by Carl Linnaeus.
105. Which of the following is an example of a flagellated Protozoan?
(a) Trypanosoma
(b) Entamoeba
(c) Paramoecium
(d) Plasmodium
Answer:
(a) Trypanosoma
Explanation:
Trypanosoma is a classic example of a flagellated protozoan (causing sleeping sickness). Entamoeba is amoeboid, Paramoecium is ciliated, and Plasmodium is a sporozoan.
