Directions: Use the information provided and your knowledge of Life Science to answer the following questions. Show all work where necessary.
Directions: Use the information provided and your knowledge of Life Science to answer the following questions. Show all work where necessary.
When bakers mix flour, water, and yeast to make dough, the yeast comes alive. Yeast are single-celled fungi, meaning each individual yeast cell is a complete living organism. They are eukaryotic, so each cell contains a nucleus, cytoplasm, and cell membrane - just like the cells in plants and animals.
Yeast cells feed on simple sugars, breaking them down through a process called cellular respiration. When oxygen is available, they perform aerobic respiration to produce energy. When oxygen is limited - such as inside dough - they switch to anaerobic respiration, also known as fermentation. During fermentation, yeast produce carbon dioxide (CO
Under a microscope, yeast appear as round or oval cells, often grouped in small clusters. Some yeast cells can be seen budding, a process where a small new cell grows from the side of a parent cell. This is how yeast reproduce asexually. Over time, many yeast cells can fill a culture or cause a loaf of bread to rise significantly.
By observing yeast activity and structure, students can collect evidence that yeast are living organisms made of cells that carry out essential life functions - growth, reproduction, and gas exchange - unlike nonliving particles such as flour or sugar grains.
Graph of Information - Figure 1.
Which observation best supports that yeast are living cells?
Using Table 1, compare the yeast culture (Sample A) with the flour grain (Sample B). Describe two differences that show which sample is living.
Are yeast living cells?
Claim:
Evidence:
Reasoning:
Explain how yeast activity inside dough provides evidence that cells carry out life functions such as gas exchange and growth.
Which process is responsible for the bubbles that make bread dough rise?
What evidence from Table 1 shows that yeast reproduce? Use specific examples from the table.