CPMT - 2004 (Botany)

Palisade parenchyma is an upper layer of ground tissue in a leaf and consists of elongated cells beneath and perpendicular to the upper epidermis. It constitutes the primary area of photosynthesis owing to the presence of large number of chloroplasts in it.

John Hutchinson was the author of a classification called as 'families of flowering plants'. It appeared in two volumes.

Spirulina is a cyanobacterium that can be consumed by humans and other animals. Its protein content is very high, about 57 gm per 100 gm.

In the early 1940s, American geneticists Edward Tatum and George Beadle evaluated Garrod's hypothesis using Neurospora. The one gene-one enzyme hypothesis is the idea that each gene encodes a single enzyme.

Rounded pots of blue-green algae (such as Nostoc) are seen in the ventral side of the thallus. These are called as slime pores. 

Opening and closure of the stomatal pore is mediated by changes in the turgor pressure of the two guard cells. The turgor pressure of guard cells is controlled by movements of large quantities of potassium ions and sugars into and out of the guard cells.

The columella is a sterile dome shaped structure that is found at the tip of a sporangiophore in Rhizopus.

If seeds sense light, they will germinate using their Pfr form. Pfr absorbs at a peak of 730 nm. The Pfr form is the active form that initiates biological responses. When Pfr absorbs far red light, it is converted to the Pr form.

Nif genes are gene encoding enzymes that are involved in the fixation of atmospheric nitrogen into a form of nitrogen that is available to living organisms. Transcription of nitrogen fixation genes in these bacteria is induced primarily by low-oxygen conditions. Rhizobium is a symbiotic bacteria that is found in the root nodules of leguminous plants.

Starch is a storage product in plants.

The word "gymnosperm" comes from the Greek word gymnospermos, meaning "naked seeds". In these, the ovules or seeds are not enclosed in an ovary.

A lichen is a composite organism. The combined life form has properties that are very different from the properties of its component organisms.

Plant ash content is a measure of the total amount of minerals that are present within a food or plant.

A good soil has an appropriate size of pores, so that it may slowly percolate the water through it.

In F1 generation, according to law of dominance the genotypes would be of Aa type. Phenotypically, they all will be of dominant type (A).

Ribulose Bisphosphate Carboxylase (RuBP Carboxylase) catalyses CO₂ fixation.
Ribulose-1,5-bisphosphate + CO₂ ----------------> 2 copies of 3-phosphoglycerate

Cell theory has become the foundation of biology and is the most widely accepted explanation of the function of cells. Hypothesis is a supposition or proposed explanation that is made on the basis of limited evidence as a starting point for further investigation.

Phosphoenolpyruvate carboxylase is an enzyme that is found in plants and some bacteria that catalyse the addition of bicarbonate to phosphoenolpyruvate to form four-carbon compound oxaloacetate and inorganic phosphate.

Mycorrhizal fungal filaments in the soil are truly extensions of root systems and are more effective in nutrient and water absorption than the roots themselves. More than 90 percent of plant species in natural areas form a symbiotic relationship with the beneficial mycorrhizal fungi.

Pyrethrins are active ingredients in pyrethrum that kill insects. Pyrethrum was a genus of several Old World plants, now classified as Chrysanthemum or Tanacetum. They are now cultivated as ornamentals for their showy flower heads.

A flower head or capitulum is a very contracted raceme in which the single sessile flowers are borne on an enlarged stem. 

Correct Answer: Both 1 and 2

Streptomycin is an antibiotic drug. It was the first of a class of drugs called aminoglycosides to be discovered and it was the first effective treatment for tuberculosis. It is derived from the actinobacterium Streptomyces griseus.

Cauliflower floret is the part of plant that most people eat.

A Ti or tumour inducing plasmid is a plasmid that often, but not always, is a part of the genetic equipment that Agrobacterium tumefaciens uses to transduce its genetic material to plants.

This is the correct answer.

Brassica has six stamens, four of which are longer than the others.

The conversion of ammonia to nitrate is performed primarily by soil-living bacteria and other nitrifying bacteria. In the primary stage of nitrification, the oxidation of ammonium is performed by bacteria (such as the Nitrosomonas species) which converts ammonia to nitrites. Other bacterial species (such as Nitrobacter) are responsible for the oxidation of the nitrites into nitrates.

The four types of gametes formed in F1 generations would be TR, Tr, tR and tr.

Circinate vernation is the manner in which a fern frond emerges. As the fern frond is formed, it is tightly curled so that the tender growing tip of the frond (and each subdivision of the frond) is protected within a coil.

Bt cotton is a genetically modified organism (GMO) cotton variety, which produces an insecticide to bollworm. It is obtained from Bacillus thuringiensis.

Coconut oil, or copra oil, is an edible oil that is extracted from the kernel or meat of mature coconuts that are harvested from the coconut palm. Coir, an important lignocellulosic fibre, can be obtained from its outer part.

Diplotene is a point at which paired chromosomes remain in contact during the first metaphase of meiosis (diplotene). At this point, crossing over and exchange of genetic material occurs between the strands.

Dendrochronology, or tree-ring dating, is the scientific method of dating that is based on the analysis of patterns of tree rings, also known as growth rings or annual rings.

The greenhouse effect is the process by which radiation from a planet's atmosphere warms the planet's surface to a temperature above what it would be without its atmosphere. If a planet's atmosphere contains radioactively active gases (greenhouse gases), the atmosphere will radiate energy in all directions.

Xenia in plants is the effect of pollen on seeds and fruit of the fertilised plant. The effect is different from the contribution of the pollen towards the next generation. The effect, such as an increase in size, on the embryo or endosperm of a plant results from fertilisation with pollen of a genetically distinct variety.

Trichoderma viride is a fungus and a biofungicide. It is used for seed and soil treatment for suppression of various diseases that are caused by fungal pathogens.

Tree rings grow under the bark and the bark is pushed out while the tree is growing. The inner part of a growth ring is formed early in the growing season, when growth is fast, and is known as early wood. The outer portion is the late wood, and is denser than early wood. This is formed by the activity of intrastelar cambium and interstelar cambium.

The G1 phase, or Gap 1 phase, is the first of four phases of the cell cycle that take place in eukaryotic cell division. In this part of interphase, the cell synthesises mRNA and proteins in preparation for subsequent steps that lead to mitosis. DNA polymerase is a protein. This is synthesised in the G1 phase.

The C4 pathway was elucidated by Marshall Davidson Hatch and C. R. Slack in Australia in 1966. It is sometimes called the Hatch-Slack pathway. This pathway is a modification of Calvin cycle and is advantageous to plants that grow in dense stands of tropical vegetation, where the CO₂ concentration may be very much reduced.

Stamens are fused together, at least partly, by the filaments so that they form two separate bundles. This is the characteristic of family Fabaceae.

Agar or agar-agar is a jelly-like substance that is obtained from red algae.

Seed dormancy is defined as a state in which seeds are prevented from germinating even under environmental conditions normally favourable for germination. The torpedo-shaped seed of a mangrove (Rhizophora maritima) is an exception. It germinates while still on the mother plant. When they fall, seed penetrates securely into soft mud flats.