Reproduction in Organisms Test - 24

Vegetative propagation involves artificial and natural means by which plants reproduce. Natural means of vegetative propagation involves sucker which is found in mint as well as banana. In this case, underground branches arise from the underground stem and protrude upward. Once branch gets matured, it separates from the parent plant and survives as an individual. So, the correct answer is option D.

• Oogamy is the common type of heterogamaous sexual reproduction in which the female gamete or egg cell is non-motile and significantly larger than the male gamete. 
• The male gametes on the other hand are motile spermatozoa that compete for fertilizing the non-motile egg. 
• Oogamy occurs in both plant and animals but also found in some protists. Thus, the correct answer is option D.

Apogamy is a type of reproduction occurring in some ferns, in which the sporophyte develops from the gametophyte without fusion of gametes. Prothallus is a green, photosynthetic, haploid gametophytic stage of fern. It is developed from germination of spore and at maturity gives rise into sexual organs, the antheridia and archegonia.

• The unbranched stem is called caudex or columnar, e.g., Palm, Sugarcane, Maize. The stem that has hollow internodes and solid prominent nodes is called culm.
  
• In the decumbent stem, the stem grows for some distance on the ground and then tries to grow upward at the tip. For example- Tridax has a decumbent type of stem. 
• The corm is a thick, large, fleshy underground stem. This is a condensed form of rhizome growing in a vertical direction.
• The sucker is the modified part of the stem and not the root.
  
• In biparous cymose branching, two lateral axes develop at a time e.g., in Mirabilis, Viscum, Stellaria, etc. In Saraca branching is of uniparous type.

Endogamy is the type of pollination in which the pollen from the anthers of a flower reaches the stigma of another flower of the same plant.
So, the correct answer is option C.

• Bulbs are underground buds with reduced stems on which short and fleshy storage leaves grow. 
• Thick scales enclose these leaves. 
• Bulbs are produced by monocotyledon plants in which the usual structure is modified for storage and reproduction. 
• The continuous sheathing leaf bases are called bulb scales. 
• The outer scales are dry and thin and the inner scales are generally fleshy and contain reserve food material.

Agave macroacantha is a group of succulent rosette plants that propagate vegetatively by aerial bulbils and ground-level basal shoots and rhizomes. In vegetative propagation the new plant is originated from the meristem. Development of shoots occurs in different parts of the rosette including aerial bulbils which are still on inflorescence.

Flowers open in centrifugal manner, i.e., opening of flowers proceeds from centre of the inflorescence to periphery.