NEET BIOLOGY

Detailed explanation-1: -Answer and Explanation: In conifers, the union of the egg and the sperm cell occurs in the female gametophyte. Sperm is released from the pollen grains and combines with the egg to form a zygote.

Detailed explanation-2: -In conifers, pollen tubes deliver the male gametes (sperm) into the egg cells, and in the process, interact with the nucellar cells of the ovule and the archegonia of the female gametophyte.

Detailed explanation-3: -In conifers, fertilization takes place when pollen from male gamete-producing cones is transferred to female gamete-producing cones, usually by the wind but occasionally by plants and animals transferring the pollen. When the pollen fertilizes the female cones, the seeds begin to develop.

Detailed explanation-4: -Figure 14.19: This image shows the lifecycle of a conifer. At what stage does the diploid zygote form? (Answer: 2-The diploid zygote forms after the pollen tube has finished forming so that the male generative nucleus (sperm) can fuse with the female egg.

Detailed explanation-5: -In gymnosperms, when the nuclei of the two sperm meet the egg cell, one nucleus dies and the other unites with the egg nucleus to form a diploid zygote. The fertilized egg undergoes mitosis to begin the development of a new sporophyte generation-the multicellular embryo of the seed.