Question

Consider the following statements
1. In pteridophytes, the phloem lacks companion cells.
2. The xylem lacks vessels in majority of pteridophytes.
3. Heterosporous pteridophytes have monoecious gametophytes.
4. Water is essential for fertilization in pteridophytes.
Which of these statements are correct?

• A. 1, 2, 3 and 4
• B. 2, 3 and 4
• C. 1 and 3
• D. 1, 2 and 4

Answer 1

Answer: (D)

Out of the given statements, 1, 2, and 4 are correct.
1. Although, Pteridophytes are the first true-land plants developed the vascular tissue, like xylem and phloem, the nature of these tissues are not like the one we see in Angiosperms. The phloem lacks both sieve tubes and the companion cells.
2. The xylem of Pteridophytes and most of the Gymnosperm members do not have vessels. They are mainly composed of Tracheids. Vessels are present in the majority of the angiosperms and some members of Gymnosperms, like Gnetales.
3. Homosporous ferns, which produce only one type of spores, like Equisetum, Pteris, etc. are monoecious. While, heterosporous ferns, like Selaginella, Salvinia, etc. are dioecious. The male gametophyte produces male gametangium only.
4. Pteridophytes are oogamous. Thus, male gametes are flagellated and are motile. Thus, fertilization is dependent on water, as the sperms can swim in the water and reach the egg cells, which are non-motile.