8 public questions tagged with this topic.
Growth in a pollen tube is measured by the increase in length as it extends toward the ovule. This follows from NCERT principle where the relation explains the outcome clearly for students in simple steps.
Ref: NCERT Biology Textbook for Class XI and XII (Botany section), Chapter: Morphology and Anatomy of Flowering Plants, Topic: Plant structure and tissue systems.
Calcium ions and attractant peptides (like LURE) secreted by synergid lls guide the pollen tube toward the embryo sac. This follows from latest NCERT 2026-27 principle explaining the concept clearly for NEET students in simple steps as per rationalized syllabus.
Ref: NCERT Biology Textbook - Latest Edition for Academic Session 2026-27 (Botany section, Rationalized Textbook for Class XI and XII), Chapter: Biology - Botany portion (Latest NCERT Textbooks for Academic Session 2026-27 -
Ovule integuments envelop nucellus and embryo sac leaving narrow canal micropyle at micropylar pole oriented toward placenta. Micropyle serves as specific entry site for pollen tube guiding sperm toward egg apparatus; synergid-secreted LURE peptides diffuse through this opening creating chemotropic gradient directing final guidance and reception of tube. Chalazal pole connects via funiculus to maternal vasculature providing nutrients, hilum marks detachment scar, chalaza opposite micropyle hosts vascular termination. Thus micropyle as pollen tube entry portal ensures precise delivery and positioning of male gametes immediately adjacent to egg and central cell.
Ref: Dresselhaus & Franklin-Tong, Nature Plants 2013: pollen tube enters ovule via micropyle guided by synergid LURE peptides.
In gymnosperms, the male gametophyte forms the pollen tube to transport sperm cells to the ovule.
Ref: NCERT Class 11 Biology Chapter 3: Plant Kingdom Angiosperms and Plant Life Cycles - Alternation of Generations
The pollen tube transports male gametes to the female gametophyte in gymnosperms.
Ref: NCERT Class 11 Biology Chapter 3: Plant Kingdom Gymnosperms - Characteristics and Life Cycle
The micropyle is an opening formed by the integuments of the ovule, allowing pollen tube entry for fertilization.
Ref: NCERT Class 11 Biology Chapter 3: Plant Kingdom Algae - Phaeophyceae and Rhodophyceae
The Filiform Apparatus consists of finger-like projections at the micropylar end of the Synergids. Its primary function is to secrete chemical attractants to guide the entry of the pollen tube into the synergid.
Ref: Detailed view of the Egg Apparatus showing cellular thickenings at the micropylar tip.
