Sometimes there is a piece of bread provided with school lunch. The bread in a school lunch is a combination of yeast, wheat flour, and other ingredients. Did you know that there was once a living organism in that roll? Yeast is a type of fungus that makes dough rise or increase in size to become soft.
The drawing below shows dry yeast from a container.
Yeast cells have organelles like those found in humans. The table below shows how yeast appears under a microscope and describes how it appears at two magnifications.
Yeast uses cellular respiration for energy. Yeast cells are able to get the materials they need through their semi-permeable membranes. Depending on the size of the molecule, some molecules may pass through freely while others may not.
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Question 1
1.
A group of students decided to investigate further whether the yeast was alive or not. They observed yeast under a microscope and made the following claims. Which student’s claim is best supported?
Question 2
2.
Based on the passage, which three characteristics can best be used to identify yeast cells as living organisms?
Question 3
3.
Yeast uses cellular respiration to fulfill its energy needs. Write a label or draw an arrow in each box to create a model showing how two substances move across a yeast cell membrane, allowing cellular respiration to occur.
Question 4
4.
The drawing below shows a classroom investigation using yeast.
Explain how the result of the investigation indicates that yeast cells use sugar for survival.
Question 5
5.
After learning about how yeast obtains energy, a group of students made a chart to compare how yeast and trees obtain energy. Circle a word or phrase in each set of options to complete the table below.