Question

Colonies of yeast fail to multiply in water but multiply in sugar solution. Choose one reason for this
A: Sugar provides energy for sustaining all life activities in yeasts
B: Water provides energy for sustaining all life activities in yeasts
C: Sugar provides a surface for sustaining all life activities in yeasts
D: All of the above

Answer 1

Yeast is a fungi which mainly multiplies by budding . For growth, yeast requires nutrition and energy which they get by glucose. It is scientifically known as Saccharomyces cerevisiae.

Complete step by step answer: Yeast belong to kingdom Fungi and are eukaryotic organisms. Yeast multiply by both sexual and asexual means. It divides asexually by formation of buds. A small bud is formed on the parent cell. The nucleus of the parent cell divides and enters the daughter cell. The bud grows and detaches itself from the parent cell and grows into a new cell. Asexual reproduction also occurs by fission in some yeasts. Sexual reproduction occurs by sporulation. Meiosis occurs in the diploid cells and produces haploid spores which after mating again produces diploid cells. Yeast has a growth time of 90 minutes. It duplicates itself in 90 minutes by budding. Yeast also requires energy for its growth, therefore, when grown in the sugar solution, yeast is able to utilize oxygen from sugar and release energy. More sugar, the more actively the yeast grows. In absence of oxygen, alcohol and carbon dioxide is released. When the yeast is in water, it is not able to derive nutrition from it and fails to grow in water.
Hence, the correct answer is option A.

Note: Yeasts originated millions of years ago. There are 1500 species of yeasts that have been recognized. These organisms are used in breweries and baking industries to produce alcohol and fermented edible products. It serves as a leavening agent.