Tag: biology

Pseudomonas fluorescens is a bacterium that has been genetically engineered to express proteins that inhibit ice crystal formation, providing frost resistance to plants.

Streptokinase is an enzyme produced by Streptococcus bacteria that acts as a clot buster by breaking down blood clots. It is produced commercially using genetic engineering.

Simmondsia chinensis (jojoba), Euphorbia abyssinica, and Euphorbia terracalla have shown promise as potential hydrocarbon or petroleum-like sources. Jojoba produces liquid wax esters similar to sperm whale oil, while certain Euphorbia species produce latex containing hydrocarbon-like compounds. Options B and C contain misspelled or incorrect plant names. Option D lists conventional oilseed plants (sesame, linseed/flax, peanut) that produce edible oils, not petroleum-like hydrocarbons.

Fluorine toxicity (fluorosis) is a significant health issue in livestock, often caused by the ingestion of forage contaminated with industrial emissions or high-fluoride water. It leads to skeletal deformities and dental issues, making animals highly susceptible to health decline.

The specialized tissue includes nectaries. Floral nectaries are generally located at the base of the perianth, so pollinators are made to brush the flower's reproductive structures, the anthers and pistil, while accessing the nectar. Nectar is a sugar-rich liquid produced by plants in glands called as nectaries, either within the flowers with which it attracts pollinating animals or by extrafloral nectaries, which provide a nutrient source to animal mutualists, which in turn provide antiherbivore protection. 
Thus, the correct answer is option C.

The entire surface of the plant consists of a single layer of cells called as epidermis or surface tissue. The entire surface of the plant has this outer layer of epidermis. Hence, it is also called as surface tissue. Most of the epidermal cells are relatively flat. The outer and lateral walls of the cell are often thicker than the inner walls. The cells forms a continuous sheet without intercellular spaces. It protects all parts of the plant. 

A xerophyte is a species of plant that has adapted to survive in an environment with little water, such as a desert or an ice or snow covered region in the Alps or the Arctic. The morphology and physiology of xerophytes are variously adapted to conserve water, and commonly also to store large quantities of water, during dry periods. Other species may be adapted to survive long periods of desiccation of their tissues, during which their metabolic activity may effectively shut down. So, thick cuticle, well developed mechanical tissue and vascular tissue are the adaptations for xerophytes. The spongy mesophyll's function is to allow for the interchange of gases (CO$ _2$) that are needed for photosynthesis.The spongy mesophyll cells are less likely to go through photosynthesis than those in the palisade mesophyll which are not required for xerophytes. 

Cotton is a soft, fluffy staple fibre that grows in a boll or protective capsule, around the seeds of cotton plants of the genus Gossypium in the family of Malvaceae. The fibre is almost pure cellulose. Under natural conditions, the cotton bolls will tend to increase the dispersion of the seeds. Cotton is a seed hair fibre produced from epidermal seed coat. Flax fibres are taken from the stem of the plant and are two to three times as strong as those of cotton. Sunn hemp is a bast fibre. Manila hemp fibres are obtained from leaf and stems. 
Thus, the correct answer is option B.

Complex tissues are those that are formed of more than one type of cells. Xylem is made up of tracheids, tracheae, xylem parenchyma and xylem fibers. Phloem is composed of sieve elements, companion cells, phloem parenchyma and phloem fibers. Hence xylem and phloem are called complex tissues. Thus the correct answer is option C.