Tips and Tricks of The Day

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Ex: The wave like contraction of the smooth muscles of digestive tract is called:
A) peristalsis                      
B) deglutition
C) fibrillation                     
D) mastication
Explanation: Peristalsis is the coordinated, rhythmic, serial contraction of smooth muscle that forces food through the digestive tact.
Ex: Flavr savr variety of Tomato is improved variety developed through incorporation of a transgene. Flavr savr variety of tomato remains fresh for long because it:       
A) has little polygalacturonase
B) abundant polygalacturonase
C) has gene for antibiotic resistance
D) lacks amylase
Explanation: In Flavr Savr variety of tomato, expression of gene for production of polygalacturonase was blocked. Enzyme polygalacturonase degrades pectin.
Ex: Cell organelles found only in plants:
A) Golgi complex
B) Mitochondria
C) Plastids
D) Ribosomes
Explanation: Plants are autotrophs and synthesize their food in the process of photosynthesis with the help of chloroplast (plastid).
Ex: Characteristic spores of diatoms are:
A) Ascospores                              
B) Basidiospores
C) Auxospores                             
D) Zoospores
Explanation: Auxospores are generally called rejuvenescent cells because they help in increasing diatom size to normal one. Auxospores are commonly formed form zygote.
Ex: A plant is kept in 300ppm CO2 concentration, what will happen to it:
A) Plant will die soon
B) Plant will grow but will not die
C) Plant will show normal photosynthesis
D) Respiration will be greatly decreased
Explanation: Normal conc. of CO2 in atmosphere is 0.03% (i.e., 300 pm). By increases but after that it decreases.
Ex: A biologist intends to use a polymerase chain reaction to perform a genetic task. The biologist probably is trying to:
A) discover new genes
B) clone a gene
C) cut DNA into many small fragments
D) isolate DNA from a living cell
Explanation: PCR is a way to dramatically increase the numbers of a particular sequence of DNA (or an entire gene). This technique is most useful when cloning DNA, since prior knowledge of the DNA sequence must first be obtained.
Ex: A few organisms are known to grow and multiply at temperatures of 100105C. They belong to
A) Thermophilic subaerial fungi
B) Marine archaebacteria
C) Thermophilic sulphur bacteria
D) Hot spring blue-green algae
Explanation: Marine archaebacteria cell consists of branched chain of lipids. This enables them to tolerate extremes of heat.
Ex: During mitosis, after the separation of centromeres, the chromatids move towards opposite poles of the spindle. Name the term used for these chromatids.
A) Daughter chromosomes
B) Kinetochores
C) Half spindles
D) Centrosomes
Explanation: During mitosis chromosomes that results from the separation of sister chromatids during cell division are called daughter chromosomes. During anaphase of mitosis, paired chromosomes (sister chromatids) separates to form daughter chromosomes. Each daughter chromosome migrates to centromere, towards the opposite ends of the cell. At the end of cell division, two distinct daughter cells are formed from a single cell.
Ex: Ambulacral grooves are absent in the living forms of the class:
A) Crinoidea
B) Ophiuroidea
C) Asteroidea
D) Echinodermata
Explanation: In class ophiuroidea, Ambulacral grooves are absent or covered by ossicles.
Ex: One of the following bacterial groups are exploited in biogas production:
A) Methogens
B) Methanotrophs
C) Organotrophs
D) Eubacteria
Explanation: Conversion of organic acid into CH4 gas by activity of methanogenic bacteria (anaerobes).