Which of the following shows a reduction of chromosomes by half? male gametophyte to flagellated sperm sporophyte to spores male gametophyte to spores female gametophyte to zygote

The correct answer is -

Sporophyte to spores.

Sporophyte can be described as multicellular, diploid phase/generation that is present in plants and algae, which undergo alternation of generation.

It produces spores (which are haploid that is having half the number of chromosomes) through the meiosis.

This is a reductional cell division.

Haploid spores develop into gametophyte, which then produces gametes that are fused and give a diploid sporophyte again.

Thus, second option shows reduction of chromosomes by half.

d is the answer

sorry if its wrong!

answer : haversian

[explanation: -(compact bone is organized as parallel columns, known as haversian systems, which run lengthwise down the axis of long bones. these columns are composed of lamellae, concentric rings of bone, surrounding a central channel, or haversian canal, that contains the nerves, blood vessels, and lymphatic system of the bone)]