All Free Biology MCQs with Answers

• A. Red pepper
• B. Black pepper
• C. Ginger
• D. Cardamom

Explanation: New world crops are those which have their centre of origin in America. Red peppers are the dried ripe fruits of Capsicum sp., indigenous to the American tropics and subtropics and the West Indies. It is a new world crop.

• A. Recessive mutation express immediately
• B. Induction of mutations is easier
• C. Culturing is easier
• D. Dominant mutation expressed immediately.

Explanation: Haploids are preferred over diploids for mutation study because in haploids recessive mutation is easier. Most of the induced mutations are recessive and these have to be in double to be expressed phenotypically. Mutations are not seen in heterozygous conditions. So, in haploid plants, recessive mutation express immediately.

• A. Reimei of rice
• B. Prabhat of arhar
• C. Sharbati sonora of wheat
• D. Aruna of castor

Explanation: Aruna of castor is a crop variety which is not due to induced mutations. Aruna variety has been developed by mutation, where the maturity period has been reduced from normal 270 days to 102 days.

• A. Require one half of nutrients
• B. Are helpful in study of meiosis
• C. Grow better under adverse conditions
• D. Form perfect homozygous.

Explanation: In crop movement programme, haploids are important because they form perfect homozygous lines. Homozygous are the pure line selection plants resulting from self-pollination. In this way, considerable homozygosity is obtained. Haploids are those plants that possess a gametophytic number of chromosomes. Haploids are used in plant breeding, especially for the production of homozygous plants and in their studies in the detection of mutation.

• A. Recombinant DNA is formed
• B. Complementary DNA is formed
• C. Mutant DNA is formed
• D. cDNA is formed

Explanation: Recombinant DNA (rDNA) molecules are DNA molecules formed by laboratory methods of genetic recombination (such as molecular cloning) to bring together genetic material from multiple sources, creating sequence that would not otherwise be found in the genome. Recombinant DNA is possible because DNA molecules from all organisms share the same chemical structure. However, a recombinant DNA formed by the fusion of DNAs taken from two organisms have remotest evolutionary relation is called chimeric DNA as well.

• A. Four nucleotides
• B. Eight nucleotides
• C. Six nucleotides
• D. Four or six nucleotides

Explanation: Restriction enzymes cut the DNA at very specific sites characterized by specific sequence of four or six nucleotides arranged symmetrically in reverse order. Such sequences are known as palindromic sequences.

• A. They cannot bind
• B. They can bind by complementary base pairing
• C. They can bind by non-complementary base pairing
• D. They cannot bind due to noncomplementary base pairing

Explanation: Due to base pairing affinity sticky ends can stick together, whenever brought closer to each other.

• A. Restriction endonuclease
• B. DNA ligase
• C. Vector
• D. Primase

Explanation: To make recombinant DNA, one often begins by selecting a vector, the means by which recombinant DNA is introduced into a host cell. One common type of vector is a plasmid.Plasmids were discovered by investigators studying the sex life of the intestinal bacterium Escherichia coll.

• A. pBR 322
• B. pSC 101
• C. RP4
• D. R388

Explanation: pSC 101 has antibiotic resistant gene for tetracycline.

• A. pSC101
• B. pBR322
• C. RP4
• D. R388

Explanation: pBR 322 has antibiotic resistant genes for tetracycline as well as ampicillin.