#neet
- It takes very long time for pineapple plants to produce flowers. Which combination of hormones can be applied to artificially induce flowering in pineapple plants throughout the year to increase yield ? Answer: 1. Auxin and Ethylene Key idea: Auxin and ethylene induce flowering in pineapple. Auxins (like NAA) and ethylene (ethephon) promote... 1
- Identify the cells whose secretion protects the lining of gastro-intestinal tract from various enzymes. Answer: 2. Goblet Cells Key idea: Mucus protects the gut lining, and goblet cells secrete mucus. Chief cells secrete pepsinogen, oxyntic (pa... 1
- Which of the following can be used as a biocontrol agent in the treatment of plant disease ? Answer: 1. textitTrichoderma Key idea: Trichoderma is a fungal biocontrol agent. Trichoderma species control plant pathogens. Chlorella is a... 1
- Phloem in gymnosperms lacks : Answer: 4. Both sieve tubes and companion cells Key idea: Gymnosperm phloem has sieve cells and albuminous cells. Sieve tubes and companion... 1
- Extrusion of second polar body from egg nucleus occurs : Answer: 1. after entry of sperm but before fertilization Key idea: Sperm entry stimulates completion of meiosis II. The secondary oocyte is... 1
- Under which of the following conditions will there be no change in the reading frame of following mRNA ?5' AACAGCGGUGCUAUU 3' Answer: 4. Deletion of GGU from 7 ^th , 8 ^th and 9 ^th positions Key idea: A change that adds or removes a multiple of 3 bases keeps the re... 1
- The concept of "Omnis cellula-e cellula" regarding cell division was first proposed by : Answer: 1. Rudolf Virchow Key idea: Rudolf Virchow proposed "Omnis cellula-e cellula" (new cells come from pre-existing cells) in 1855. Schl... 1
- What triggers activation of protoxin to active Bt toxin of Bacillus thuringiensis in boll worm ? Answer: 3. Alkaline pH of gut Key idea: The Bt protoxin is activated by alkaline pH. Bt toxin crystals exist as inactive protoxin. In the al... 1
- Identify the correct pair representing the causative agent of typhoid fever and the confirmatory test for typhoid. Answer: 4. textitSalmonella typhi / Widal test Key idea: Typhoid is caused by Salmonella typhi and diagnosed by the Widal test. Plasmodium v... 1
- What is the genetic disorder in which an individual has an overall masculine development, gynaecomastia, and is sterile ? Answer: 2. Klinefelter's syndrome Key idea: Klinefelter's syndrome is XXY. The individual is male with overall masculine development but als... 1
- Polyblend, a fine powder of recycled modified plastic, has proved to be a good material for : Answer: 3. construction of roads Key idea: Polyblend, made from recycled modified plastic, is used to lay roads. It is mixed with bitumen to... 1
- What is the direction of movement of sugars in phloem ? Answer: 4. Bi-directional Phloem moves sugars from a source to a sink. The source and sink can be anywhere, so movement can be upward or dow... 1
- Persistent nucellus in the seed is known as : Answer: 2. Perisperm In most seeds the nucellus is used up. In some, such as black pepper and beet, a part of it persists and is called peri... 1
- Xylem translocates : Answer: 4. Water, mineral salts, some organic nitrogen and hormones Xylem sap carries mostly water and minerals, but also some organic nitro... 1
- Cells in G_0 phase : Answer: 3. suspend the cell cycle Cells that do not divide further leave the active cycle at G₁ and enter the quiescent G₀ stage. They remai... 1
- DNA precipitation out of a mixture of biomolecules can be achieved by treatment with : Answer: 2. Chilled ethanol DNA is precipitated by adding chilled ethanol, and it then appears as fine threads that can be spooled out. Optio... 1
- Select the correct group of biocontrol agents. Answer: 2. *Trichoderma*, *Baculovirus*, *Bacillus thuringiensis* Biocontrol agents include Bacillus thuringiensis (bacterium), Trichoderma... 1
- Select the incorrect statement. Answer: 3. Inbreeding selects harmful recessive genes that reduce fertility and productivity. Inbreeding increases homozygosity, helps make... 1
- Match the following organisms with the products they produce :(a) *Lactobacillus* (i) Cheese(b) *Saccharomyces cerevisiae* (ii) Curd(c) *Aspergillus niger* (iii) Citric Acid(d) *Acetobacter aceti* (iv) Bread(v) Acetic AcidSelect the correct option. Answer: 2. (a) (ii) (b) (iv) (c) (iii) (d) (v) Lactobacillus makes curd (ii). Saccharomyces cerevisiae is used for bread (iv). Aspergillus n... 1
- In some plants, the female gamete develops into embryo without fertilization. This phenomenon is known as : Answer: 4. Parthenogenesis Development of an egg or female gamete into an embryo without fertilisation is parthenogenesis. Autogamy is self-... 1
- What map unit (Centimorgan) is adopted in the construction of genetic maps ? Answer: 3. A unit of distance between genes on chromosomes, representing 1% cross over. One map unit (centimorgan) is the distance between g... 1
- What would be the heart rate of a person if the cardiac output is 5 L, blood volume in the ventricles at the end of diastole is 100 mL and at the end of ventricular systole is 50 mL ? Answer: 3. 100 beats per minute Cardiac output = stroke volume × heart rate. Stroke volume =100-50=50 mL. Heart rate=5000 mL/min/50 mL/beat=... 1
- *Thiobacillus* is a group of bacteria helpful in carrying out : Answer: 4. Denitrification Thiobacillus species oxidise sulphur compounds. The key lists Thiobacillus denitrificans, which converts nitrate... 1
- Which of the following factors is responsible for the formation of concentrated urine ? Answer: 2. Maintaining hyperosmolarity towards inner medullary interstitium in the kidneys. Concentrated urine needs a steep osmotic gradien... 1