#ssc 10th
- The male reproductive part of a flower is the Answer: B. stamen The stamen (anther and filament) produces pollen grains. 1
- If Planaria is cut into pieces, each piece grows into a complete organism. This is called Answer: A. regeneration Regeneration is the formation of a complete organism from a body part. 1
- In angiosperms, the endosperm formed after double fertilization is Answer: D. triploid (3n) One male gamete fuses with the diploid secondary nucleus, giving a triploid endosperm. 1
- In human beings, fertilization takes place in the Answer: A. fallopian tube (oviduct) The sperm and ovum fuse in the fallopian tube; the zygote then moves to the uterus. 1
- The menstrual cycle in human females usually lasts about Answer: D. 28 days The menstrual cycle is about 28 days long. 1
- Identical (monozygotic) twins develop from Answer: A. one zygote that splits into two Monozygotic twins come from a single zygote that splits, so they have the same genetic material. 1
- The sexually transmitted disease syphilis is caused by Answer: D. Treponema pallidum Syphilis is caused by the bacterium Treponema pallidum. Neisseria gonorrhoeae causes gonorrhoea, HIV causes AI... 1
- The number of chromosomes in a human sperm cell is Answer: A. 23 Gametes are haploid, so a sperm has 23 chromosomes (22 autosomes + X or Y). 1
- Curd is formed from milk by the action of Answer: A. Lactobacillus bacteria Lactobacilli convert lactose of milk into lactic acid, which sets the milk into curd. 1
- The microorganism used in making bread is Answer: D. yeast Yeast (Saccharomyces) ferments sugar and releases CO₂ , which makes dough rise. 1
- The antibiotic penicillin was discovered by Answer: C. Alexander Fleming Alexander Fleming discovered penicillin from the fungus Penicillium in 1928. 1
- Lactobacilli convert the lactose in milk into Answer: A. lactic acid Lactic acid fermentation by Lactobacillus converts lactose into lactic acid. 1
- Antibiotics are effective against diseases caused by Answer: C. bacteria Antibiotics act on bacteria; they do not cure viral diseases such as the common cold. 1
- Methane in biogas is produced by Answer: B. methanogenic bacteria Methanogens decompose organic matter anaerobically and release methane. 1
- Vinegar (acetic acid) is produced with the help of Answer: D. Acetobacter Acetobacter aceti oxidises ethanol into acetic acid (vinegar). 1
- The conversion of sugar into ethanol and carbon dioxide by yeast is called Answer: A. fermentation Yeast carries out alcoholic fermentation: sugar → ethanol + CO₂ . 1
- Citric acid is produced industrially using the fungus Answer: B. Aspergillus niger Aspergillus niger is used for the commercial production of citric acid. 1
- Which cell organelle is called the powerhouse of the cell? Answer: D. Mitochondria Mitochondria carry out aerobic respiration and produce ATP. 1
- Glycolysis takes place in the Answer: D. cytoplasm Glycolysis, the first stage of cellular respiration, occurs in the cytoplasm. 1
- Bacteria such as Pseudomonas are used to clean up oil spills. This use of microbes to remove pollutants is called Answer: B. bioremediation Using microbes to break down pollutants is bioremediation. 1
- Mitosis takes place in Answer: A. somatic (body) cells Mitosis occurs in somatic cells for growth and repair; meiosis occurs in germ cells to form gametes. 1
- Bread dough becomes spongy because yeast produces Answer: A. carbon dioxide CO₂ released during fermentation makes the dough rise. 1
- A vaccine works by Answer: A. stimulating the body to produce antibodies against a pathogen A vaccine contains weakened or killed pathogens (or their parts) th... 1
- Dr. Verghese Kurien is known as the father of the Answer: A. White Revolution Dr. Verghese Kurien led the White Revolution (Operation Flood) in milk production. 1