Phanerogams-Gymnosperms (IFS (Forests Services) Botany (Mains)): Questions 1 - 9 of 9

Pinus is gymnosperms and it has a naked seed. After the gametophyte ovum is fertilized to become a zygote and the ovule becomes a seed.

Spores are the main units for the gametophytic life cycle.

• In pinus, spores are mainly two types; microspores and megaspores.

• Microspores are germination to give rise to male gametophyte and megaspores germination to give rise to female gametophyte.

• In Pinus male gametophyte, microspore is the unit of it.

• Microspore is also called

Definition:

• Transfusion tissue is lying on the vascular bundles of gymnosperm leaves and consists of both living cells like those of parenchyma with walls that are not lignified and thin-walled but lignified tracheids with bordered pits.
• Transfusion tissue is composed of tracheids with bordered pits and parenchyma cells containing tannin-like s

• Gymnosperms do not produce fruit, their seeds are naked or exposed to the elements without a layer of fruit to protect them.

• Gymnosperms are different from angiosperms on the basis of the naked-seed habit and enclosure of seeds within a fruit in the latter.

• Gymnosperm pollen lands directly on the ovule, where in angiosperm pollen lands

Anatomy of Pinus needle or Pinus leaf:

Epidermis:

• Single layered, thick walled and cutinized.

• Stomata are distributed the entire surface of the leaf, so the leaf is described as amphi

• The plants are woody and perennial.

• The stele is eustelic. Secondary growth as in dicots. The secondary wood may be manoxylic or pycnoxylic.

• The vascular tissue is well developed, but vessels are absent (except in Gnetum). Phloem is devoid of companion cells.

• Both are heterosporic and endosporic.

• Megaspore is retained in the meg

The secondary wood in the gymnosperms may be manoxylic or pycnoxylic.

Manoxylic wood:

• Manoxylic wood is soft and parenchymatous.

• Manoxylic wood is not commercially useful.

• Manoxylic wood is the non-compact wood with large pith and cortex mixed with less amount of xylem tracheids or wood.

• Parenchyma cells are filled with starch gra

• The earliest seed plants produced seeds that sat unprotected on the surface of leaves or modified stems.

• As they are first vascular plants that are totally independent of water bodies for their fertilization as there e ancestor needs water for their fertilization purpose.

• These first seed plants hide their seed beneath their cones scale

Transfusion tissue is the tissue that is found around the vascular bundle of gymnosperm leaves.

Structure and location

• There are group of bracket like cells on the lateral side of the vascular xylem in the mid represent the cells are small and broad pits and have reticulate thickening on there was there called transfusion tissue.

• In the w