in recombinant dna experiments, is used to cut pieces of dna, and joins these segments.

Explanation:

in recombinant DNA experiments, __restriction enzymes__ is used to cut pieces of DNA, and __DNA ligase_ joins these segments.

if your own plato the answer is b. the fern transitioned from sporophyte generation to gametophyte generation.

the level of progesterone is low at the pre-ovulatory phase of the cycle but it gradually increases and the levels are high at the luteal phase. if pregnancy occurs, the level of progesterone will be high throughout the pregnancy.

if egg is fertilized and the mother gets pregnant, progesterone starts preparing the uterus for the implantation. it starts building up the lining of uterus and make it hostile of the period of pregnancy.