UPCPMT (Botany - 2009)

Potatoes are underground stem tubers. Underground stems are modified plant structures that derive from stem tissue but exist under the soil surface.

Each androcyte metamorphoses into a coiled (2-3), multi-flagellate and multiciliate antherozoid or spermatozoid.

Ginger rhizome is a short and dorsoventrally flattened underground stem which creeps horizontally beneath the surface of the ground. It is fleshy due to storage material.

In open vascular bundles, a layer of cambium will be present between the xylem and phloem. This enables secondary growth in it.

Coir (the fiber from the husk of the coconut) is used in ropes, mats, door mats, brushes and sacks. It is obtained from the mesocarp of a coconut.

It is characterised by morphologically dissimilar spores that are produced from two types of sporangia. These are microspores or male spores and megaspores (macrospores) or female spores. The arrangement of the young leaves within a bud is vernation. In cycas, circinate vernation is there.

The sporogonium of Funaria is photosynthetic. It has stomata present on its seta part. Seta is a long stalk with a pear-shaped capsule by its tip.

Tracheophytes are plants with a vascular system. They include angiosperms and gymnosperms such as ferns and seed plants.

A greenhouse gas is a gas in the atmosphere that absorbs and emits radiation within the thermal infrared range. This process is the fundamental cause of the greenhouse effect. The main greenhouse gas is carbon dioxide.

During the development of seeds, the nucellar tissue which surrounds the megagametophyte can produce additional embryos (polyembryony). These are genetically identical to the parent plant. This is the common feature in citrus fruits.

During its transit inside the pollen tube, the generative cell divides to form two male gametes. The third cell is the pollen tube cell.

The C3 cycle is initiated by the enzyme Rubisco that catalyses the carboxylation of the CO₂ acceptor molecule ribulose-1,5-bisP (RuBP). It results in the formation of 3-phosphoglyceraldehyde.

In Polygonum type of development, the functional megaspore passes through three mitotic divisions to produce a seven-celled embryo sac.

PEP is the first acceptor of carbon dioxide in C4 plants.

Capillary water is the water that remains in the soil after the water drains. It permits plants to survive through periods of drought.

Fungi possess cell walls that are made of the glucosamine polymer chitin and glucans.

Plant ash includes all the mineral salts absorbed by the roots of the plants and the total organic matter present in the plants.

It is the second growth period of the cell cycle, following DNA replication and preceding prophase, during which the cell forms the materials that make up the spindle. RNA and non-histone proteins are synthesised in this phase.

In aerobic respiration, the terminal electron acceptor is oxygen. Anaerobes have a lot of terminal electron acceptors.

A bract is a modified or specialised leaf, especially the one associated with a reproductive structure such as a flower.

Gibberellin hormone induces flowering in plants without cold temperature treatment or vernalisation.

Thigmotropism is the directional response of a plant organ to touch or physical contact with a solid object. It is best seen in leaves or tendrils.

A potometer is a device used for measuring the rate of water uptake of a leafy plant shoot. The main reason for water uptake by a cut shoot is transpiration (evaporation in plants). It is affected by the transpiration stream.

The polymerase chain reaction (PCR) is a technique that is used in molecular biology to amplify a single copy or a few copies of a piece of DNA across several orders of magnitude, generating thousands to millions of copies of a particular DNA sequence.

Mutation occurs when a DNA gene is damaged or changed in such a way as to alter the genetic message carried by that gene. It is more common in dominant condition as it is expressed here.

It is completely inverted so that the micropyle is facing downwards and situated near the base of the funiculus. It is the most common type of ovule found in angiosperm (all plants of gamopetalae).

The offsprings will have the genotypes RrTt, rrTt, Rrtt and rrtt. All will have different phenotypes.

Sporopollenin is one of the most chemically inert biological polymers. It is a major component of the tough outer (exine) walls of plant spores and pollen grains. It is chemically very stable and is usually well preserved in soils and sediments.

Producers or green plants perform photosynthesis and use sunlight as a source of energy.

Organic matter such as decomposing leaves are present in horizon O (humus or organic).

Wolffia, a hydrophyte, is the smallest angiospermic flower known.

An energy pyramid is a graphical model of energy flow in a community. The different levels represent different groups of organisms that might compose a food chain. It is always upright.

This is the transition zone between two different plant communities such as between forest and prairie.

Fibroin is an insoluble protein present in silk created by spiders, the larvae of Bombyx mori etc.