Biology - Online Test
Q1. First organic acid produced by microbial fermentation is
Answer : Option D
Explaination / Solution:
Lactic acid occurs in two isomeric forms i.e. L (+) and D (-) isomers, and as a racemic mixture (DL-lactic acid). The isolation of lactic acid from milk was done in 1798. It was the first organic acid produced by microorganisms in 1880. Today, lactic acid is competitively produced both by microbiological and chemical methods.
Q2.
Read the following statements:
i. carbondioxide is a qualitative pollutant.
ii. carbondioxide is already present in environment and is termed as pollutant when it’s concentration increases in the environment:
Answer : Option B
Explaination / Solution:
Carbon dioxide is a quantitative pollutant. This gas is already present in environment in small quantity. When its concentration increases in the environmentit is termed as pollutant. It may cause greenhouse effect also.
Q3. When two parents participate in reproductive process and also involve fusion of their gametes, it is called
Answer : Option C
Explaination / Solution:
In sexual reproduction male and female gametes are produced by male and female organism. The fusion of gametes results into zygote formation that finally develops as new offspring.
Q4. The axillary buds of stems may also get modified into woody, straight and pointed thorns in
Answer : Option C
Explaination / Solution:
The axillary buds of stems may also get modified into woody, straight and pointed thorns in Citrus and Bougainvillea. They protect plants from browsing animals.
Q5. In animal cells, the mitotic division is seen in
Answer : Option B
Explaination / Solution:
In animals, mitotic cell division is only seen in the diploid somatic cell since mitosis produces cells with same number of chromosomes as that of parents.
Q6. The technique used to produce large number of genetically identical offspring is called as
Answer : Option A
Explaination / Solution:
Cloning is the production of an exact copy of an animal by means of asexual reproduction. Any two animals which contain exactly the same genes are called genetically identical.
An animal which is genetically identical to its parents is called clone.
The cloning of a large animal was successfully done for the first time by Ian Wilmut and his colleagues at the Roslin Institute in Edinburg.
They cloned a sheep named Dolly from its parent sheep called Finn Dorest sheep.
Q7. The part of a nephron which adds some material to the filtrate is :
Answer : Option C
Explaination / Solution:
Each nephron consists Bowman’s cup, tubules and loops of Henle’s. filtration of blood occurs in glomerulus cells present in Bowman’s cup. Some materials are added to initial filtrate in distal convoluted tubule.
Q8. Which of the following amino acids was not found to be synthesized in Miller’s Experiment?
Answer : Option C
Explaination / Solution:
The famous experiment of Urey and Miller regarding origin of life from inorganic substance produced amino acids, sugar and nitrogenous base etc. glutamic acid was not found in this experiment.
Q9. Which one is not a xylem cell?
Answer : Option C
Explaination / Solution:
Xylem is a complex tissue, which consists of four kinds of cells. These cells are tracheid, vessels, xylem parenchyma and xylem fibers. Companion cell is part of phloem tissue.
Q10. All changes that an organism goes through during its life cycle is called as
Answer : Option B
Explaination / Solution:
Development is a term that includes all changes that an organism goes through during its life cycle from germination of the seed to senescence.
