Write the types of sex-determination mechanisms the following crosses show. Give an example of each type
(i) Female XX with Male XO
Write the types of sex-determination mechanisms the following crosses show. Give an example of each type
(ii) Female ZW with Male ZZ
Name the scientist who suggested that the genetic code should be made of a combination of three nucleotides.
State how Agrobacterium tumifaciens has been made a useful cloning vector to transfer DNA to plant cells.
Apart from being a part of the food chain, predators play other important roles. Mention any two such roles supported by examples.
How are 'sticky ends' formed on a DNA strand? Why are they so called?
Sticky ends are produced by restriction enzymes. These enzymes cut the strand of DNA a little away from the centre of the palindrome sites but between the same two bases on the opposite strands. This leaves single-stranded portions at the ends. These overhanging stretches are called 'sticky ends'.
These are called sticky ends because they form hydrogen bonds with their complementary cut counterparts. This stickiness of the ends facilitates the action of the enzyme DNA ligase.