Biology - Online Test
Q1. M phase represents
Answer : Option B
Explaination / Solution:
The M Phase represents the phase when the actual cell division or mitosis occurs/starts during cell cycle.
Q2. EtBr fluoresces at the wavelength
Answer : Option B
Explaination / Solution:
Ethidium bromide is an intercalating agent commonly used as a fluorescent tag (nucleic acid stain) in molecular biology laboratories for techniques such as agarose gel electrophoresis. It is commonly abbreviated as "EtBr", which is also an abbreviation for bromoethane. When exposed to ultraviolet light, it will fluoresce with an orange colour, intensifying almost 20-fold after binding to DNA. It fluoresces at the wavelength at 254 nm.
Q3. Ascending limb of Henle’s loop is not permeable for :
Answer : Option A
Explaination / Solution:
Ascending limb of Henle’s is not permeable to water. The descending limb is although permeable to water. Counter current exchange takes place between the loop of Henle’s and arteries surrounding it.
Q4. The first organisms were
Answer : Option D
Explaination / Solution:
The first organisms were chemo heterotrophs. This is because, oxygen was absent on previous earth when organisms have evolved. Chemo heterotrophs can obtain energy from chemicals like sulpher and phosphorus.
Q5. A speciallised parenchymatous cells, which are closely associated with sieve tube elements is
Answer : Option D
Explaination / Solution:
The companion cells are specialised parenchymatous cells, which are closely associated with sieve tube elements. The sieve tube elements and companion cells are connected by pit fields present between their common longitudinal walls.
Q6. Auxins are generally produced in
Answer : Option D
Explaination / Solution:
Auxins promote stem elongation, inhibit growth of lateral buds (maintains apical dominance). They are produced in the stem, buds, and root tips.
Example: Indole Acetic Acid (IA).
Auxin is a plant hormone produced in the stem tip that promotes cell elongation
Q7. In MagniferaindicaLinn, ‘Linn’ denotes
Answer : Option D
Explaination / Solution:
In MangiferaindicaLinn, the word ‘Linn’ indicates that this species was first described by Linnaeus. Hence, the correct option is The name of the author who first described the species.
Q8. Muscles are attached to bones via :
Answer : Option A
Explaination / Solution:
Muscles are attached to bones by tendon and bones are attached with another bone by ligaments. Tendon and ligaments are types of connective tissue.
Q9. Cry I Ab controls
Answer : Option D
Explaination / Solution:
The Bt toxin is encoded by the cry gene. The cry I AC and cry II Ab control cotton boll worms, while the cry I Ab controls corn borer. Bt gene produces Bt toxin. This toxin provides resistance to plants against lepidopteron, coleopteron and dipterans pests.
Q10. Introduction of sex education in schools should be encouraged to
Answer : Option C
Explaination / Solution:
Sex education in schools should be encouraged to provide right information to young and to discourage children from believing in myths and misconceptions about sex related aspects.
