Botany and Plant Science

Shoot or stem develops from plumule. Shoot or stem develops from plumule. Plumule is the future shoot of a plant as radicle is the future root of the plant. Plumule is positively phototrophic.
Thus, the correct answer is option A.

Cucurbita stem has lacunar collenchyma or tubular collenchyma which is characterized by the presence of distinct intercellular spaces and deposition of pectocellulose is on the wall of intercellular spaces. Sunflower stem has lamellar or plate collenchyma which is characterized by cell wall thickening on the tangential walls giving the cell lamellar or plates like appearance. Brinjal stem has angular collenchyma which is characterized by deposition of pectocellulose are at the angles of the cell. Maize stem has sclerenchymatous hypodermis.
Therefore, the correct answer is option A.

The tapetal layer is of great physiological significance as all the food material entering into the sporogenous tissue diffuses through this layer. Ultimately the cells of tapetal layer disorganise. Thus, tapetum makes a nutritive layer for the developing microspores or pollen grains.

Vascular bundles (xylem and phloem) are present in all higher plants including Pteridophytes, Gymnosperms, and Angiosperms. Therefore, none of the listed groups lack them.

Pollen grains form the first cell of male gametophytic generation.It divides into two unequal cells; a small generative cell and a larger vegetative cell. During the germination of pollen tube over the carpel, the vegetative tube nucleus migrates into the pollen tube and reaches up to the distal end. The generative cell also migrates into the pollen tube and divides to form two male gametes. Each male gamete consists of a large nucleus surrounded by a thin sheath of cytoplasm. 

• In angiosperms, as the pollen tube penetrates the ovule, it releases two sperm cells. One fuses with the egg to create a diploid zygote which develops into an embryo, while the other joins with the fusion nucleus to form a triploid nucleus that develops into endosperm.
  
• So the correct answer is ' Diploid'.

The specialized tissue includes nectaries. Floral nectaries are generally located at the base of the perianth, so pollinators are made to brush the flower's reproductive structures, the anthers and pistil, while accessing the nectar. Nectar is a sugar-rich liquid produced by plants in glands called as nectaries, either within the flowers with which it attracts pollinating animals or by extrafloral nectaries, which provide a nutrient source to animal mutualists, which in turn provide antiherbivore protection. 
Thus, the correct answer is option C.

The entire surface of the plant consists of a single layer of cells called as epidermis or surface tissue. The entire surface of the plant has this outer layer of epidermis. Hence, it is also called as surface tissue. Most of the epidermal cells are relatively flat. The outer and lateral walls of the cell are often thicker than the inner walls. The cells forms a continuous sheet without intercellular spaces. It protects all parts of the plant. 

A xerophyte is a species of plant that has adapted to survive in an environment with little water, such as a desert or an ice or snow covered region in the Alps or the Arctic. The morphology and physiology of xerophytes are variously adapted to conserve water, and commonly also to store large quantities of water, during dry periods. Other species may be adapted to survive long periods of desiccation of their tissues, during which their metabolic activity may effectively shut down. So, thick cuticle, well developed mechanical tissue and vascular tissue are the adaptations for xerophytes. The spongy mesophyll's function is to allow for the interchange of gases (CO$ _2$) that are needed for photosynthesis.The spongy mesophyll cells are less likely to go through photosynthesis than those in the palisade mesophyll which are not required for xerophytes. 

Procambium is a primary meristematic tissue that differentiates into primary vascular tissues, specifically the primary xylem and primary phloem. It is distinct from the vascular cambium, which is a secondary meristem.

1. Vascular tissue system includes xylem and phloem and helps in food and water conduction.
2. Ground tissue system mainly consists of simple tissues such as parenchyma, collenchyma, and sclerenchyma. Parenchyma is usually present in cortex, pericycle, pith and medullary ray.
3. Epidermal tissue system forms the outer -most covering of the complete plant body. Stomata are present here.
4. Meristematic tissue contributes to the primary growth of the plant and includes apical and intercalary meristems.

Lacticiferous vessels are found in plants that produce latex. Laticifers are connected longitudinally to form long chains of coenocytic cells. Laticifers or lacteal ducts are located in the cortex and are specialized type of parenchymatous cells.
So, the correct answer is 'Cortex'

In a stele, if phloem is both external and internal to xylem, it is called as bicollateral, as found in leaves mostly and in a few stems. This can be seen in Solanaceae and Cucurbitaceae family.