Which of the following statements is correct with respect to bryophyte development?
haploid gametes mate to produce a diploid zygote, which later develops into a protonema.
the diploid zygote germinates to give rise to protonema, which later develops into a sporophyte.
haploid spores germinate to give rise to protonema, which later develops into a sporophyte.

The answer is Haploid spores germinate to give rise to protonema, which later develops into a sporophyte.

A protonema (plural: protonemata) is a thread-like chain of cells that forms the earliest stage (the haploid phase) of a bryophyte life cycle..
A haploid gametophyte ( each of whose cells contains a fixed number of unpaired chromosomes)  gives rise to a diploid sporophyte,. Gametophytes produce haploid sperm and eggs which fuse to form diploid zygotes that grow into sporophytes.

estuaries are the partially enclosed coastal bodies of brackish water formed at the mouth of sea where river meets an ocean. it is a transition zone between river and sea water so estuaries are influenced to both marine environment such as tides, waves and to riverine such as flow of fresh water and sediments. the mixing of sea and fresh water provide high level of nutrients, making estuaries a high product habitats.

many estuaries suffers degradation from a variety of human activities like erosion from deforestation, overgrazing, overfishing, drainage and eutrophication.

so from the above statement answers will be

1. false as estuaries are formed due to both brackish and freshwater.

2.true, due to high productivity estuaries are breeding ground for many marine species.

3. direct and indirect activities of man that contribute to pollution and deposition of sediments.