Question

In ginkgoales, the male gametes are
A. Motile
B. Non-motile
C. Amoeboid
D. Absent

Answer 1

Hint:- The Ginkgoales are a group of Permian-dated gymnosperms. It is assumed that the group is more closely related to conifers than any other gymnosperm. Ovulate, pollen-bearing systems are formed by ginkgo trees. These structures are dioecious, in that various Ginkgo plants originate in male and female structures. Ginkgo biloba reproduces sexually. Morphologically, before reproductive organs are created, the male and female plants are indistinguishable. The male and female trees may, however, be cytologically differentiated at an early stage.

Complete Answer:- In almost any temperate or Mediterranean climate, Ginkgo biloba is a highly adaptable plant that can grow. It is immune to contamination and to pests as well. Ovulate, pollen-bearing systems are formed by ginkgo trees. These structures are dioecious, in that various Ginkgo plants originate in male and female structures. The pollen organs are very similar to catkins that are angiospermous. They come from the axils of the scales of the buds and the leaves from the spur shoots of the Ginkgo tree. At the tips of sporophylls on the strobiloid, pollen is found in sacs of two to four. Ginkgo trees' ovules come from leaf axil stalks on short shoots, each carrying two ovules. The flagellated male gametes fertilise the ovulum, which can move about freely. In the spring, this fertilisation method starts on the tree itself.
Ginkgo-like fossils are preserved under a morphogen called Ginkgo Xylon, Ginkgo Melanoxylon, or Proto Ginkgo Xylon. There is no common finding of fossilised ginkgophyta wood in the record, probably because it degrades easily, and probably because it is difficult to tell apart from the far more pervasive samples of conifer. It has a secondary thin-walled xylem, like conifer wood, and a main vascular system consisting of eustele and bifacial vascular cambium.
Ginkgoales, which are part of the gymnosperm division, have reproductive organs in the form of cones or strobili. Although the male cones are composed of microsporophylls, the megasporophylls are composed of female cones. Microsporophylls hold microsporangia and a large number of microspores or grains of pollen, which form the male gametophytes later on. The male gametes in them are motile.

Hence, the correct answer is (a) Motile

Note:- The modern Ginkgo biloba 's distinctive form gives the appearance of a rather narrow morphology of the leaves, but the group is varied and diverse. The Ginkgo genus itself comprises a number of morphologies.