The egg apparatus in the embryo sac consists of one central egg cell and two flanking cells known as synergids. Synergids play a crucial role in guiding the pollen tube toward the egg cell during the process of fertilization.
962
Which structure develops into the testa and tegmen of a seed?
The ovule integuments are the protective layers surrounding the nucellus. Following fertilization, the outer integument typically develops into the testa (outer seed coat), while the inner integument develops into the tegmen (inner seed coat), providing essential protection for the embryo.
963
Which of the following structures represents the female reproductive component of a flower?
The carpel (or pistil) is the female reproductive organ of the flower. It consists of the stigma, style, and ovary. The ovary contains the ovules, which, after fertilization, develop into seeds, while the ovary itself matures into the fruit.
964
In which plant structure are the ovules and seeds typically enclosed?
In angiosperms, the ovules are contained within the ovary, which develops into the fruit after fertilization. This enclosure provides additional protection to the developing seeds, a key characteristic distinguishing angiosperms from gymnosperms.
965
What are the cells located at the chalazal end of the female gametophyte called?
In the mature embryo sac of angiosperms, the three cells situated at the chalazal end are known as antipodal cells. These cells are typically haploid and play a role in the nutrition of the developing embryo sac before eventually degenerating after fertilization.
966
Microspores germinate to develop into which of the following structures?
In the life cycle of seed plants, microspores are the haploid cells that undergo mitosis to develop into the male gametophyte, commonly known as the pollen grain. This gametophyte is responsible for producing the male gametes required for fertilization within the ovule of the flower.
967
Which structure develops into the protective seed coat following fertilization?
The integuments are the outer layers of the ovule that surround the nucellus. After fertilization occurs, these integuments undergo maturation and hardening to form the seed coat, or testa, which serves to protect the embryo from desiccation and mechanical injury.
968
In the mature embryo sac of angiosperms, what is the collective term for the group of three cells located at the micropylar end?
The egg apparatus consists of three cells: one central egg cell and two flanking synergids. These are situated at the micropylar end of the embryo sac and are essential for the fertilization process in flowering plants.
969
Where are the female gametophyte cells typically located within the ovule?
The female gametophyte, or embryo sac, is contained within the ovule. The chalazal end is the base of the ovule opposite the micropyle. In a typical polygonum-type embryo sac, the antipodal cells are located at the chalazal end, while the egg apparatus is located near the micropylar end.
970
The gametophyte generation in plants is characterized by which ploidy level?
In the alternation of generations, the gametophyte is the haploid phase of the plant life cycle. It develops from haploid spores produced through meiosis and is responsible for producing gametes via mitosis, which later fuse to form the diploid sporophyte.
