This page shows a list of topics in the 8th Grade MISA public release collection at MSDE. 8th Grade MISA
Released Questions in Topic "Life Science"

During a class investigation on cells, students observed different cell types using a compound light microscope and prepared slides. The following diagrams show some of the cells the students observed.

After examining the cells using a microscope, the students researched some of the cells observed. The students found that each individual amoeba is able to carry out all the functions necessary for life. The amoeba moves by changing the position of its cytoplasm. The amoeba uses cellular respiration to convert food into energy. Another organism that is similar to the amoeba is the euglena. Each individual euglena is able to carry out all necessary functions for life. One of the ways the euglena differs from the amoeba is that the euglena uses photosynthesis to produce the energy needed for its survival. Another way the euglena differs from the amoeba is in movement. The euglena has a tail, called a flagella, that propels the euglena.

As the students continued their research, they found evidence that indicated that humans and other complex organisms have many cells that are found in only one system of an organism’s body. Their research also stated that it is estimated that on average 37.2 trillion cells compose a human body. Some of these cells are intestinal cells, heart muscle cells, and nerve cells. These cell types are shown in the following diagram.

The students also found that researchers are trying to determine the number of different cell types there are in the human body. Until recently, scientific evidence supported the claim that the human body has approximately 200 cell types, each with a unique function. Researchers are now analyzing the different cell types and have found that there are many more types than previously thought.

During the microscope investigation, the students observed the amoeba and euglena.

The observations on the amoeba and euglena provide evidence that

During the microscope investigation, the students observed cells.

Evidence from the investigation supports the classification of humans and onions as

The students continued using the microscope and compared table salt to the onion cells they previously observed. A diagram of the table salt is shown.

The students’ research indicated that heart muscle cells are only one type of cell in the circulatory system and that the circulatory system is composed of several organs working together.

Which other circulatory system organ works directly with the heart to ensure other body tissues receive oxygen?

The students' research indicated that the human body is composed of cells.

Place each body structure into the table in order of least complex organization to most complex organization.

The students found that intestinal cells are part of an organ in the digestive system.

Use evidence to explain how the intestinal cells help the intestines work within the digestive system. In your explanation, be sure to include

• the role of the intestines in the digestive system

• the interacting components in the intestines

After a school trip to an aquarium, students from a science class researched some of the organisms that live in coral reef ecosystems. The students’ research indicated that coral reefs are made up of small organisms called corals and each individual coral is called a polyp. Corals secrete calcium carbonate to form an exoskeleton, and as the corals die off, these exoskeletons build up and form a limestone foundation. New corals attach themselves to the limestone foundation and slowly form coral reefs. The following diagram shows a colony of corals and a coral polyp.

The students’ research indicated that corals are animals that consume a variety of other small organisms. Corals are able to reproduce both sexually and asexually. The corals use asexual reproduction to expand colonies and use sexual reproduction to form new colonies that can be far away from the parents. Stony corals and other coral species that build reefs prefer to live in warm, shallow water that is 20–29 degrees Celsius (°C). The following map shows where coral reefs are located on Earth.

The students’ research indicated that climate change is causing ocean temperatures to rise. These rising temperatures are making the ocean unlivable for coral reefs. Corals are sensitive to water temperature, and when water temperatures change beyond a livable range, the corals become stressed. This stress causes the corals to shed photosynthetic algae and other microorganisms that live on the corals. This shedding of organisms causes the corals to turn white in an event known as bleaching. When water temperatures return to a livable range, many coral reefs have been destroyed by the bleaching and do not recover. A recent study stated that corals that are able to store larger energy reserves in the form of fat in their cells and are able to partner with multiple species of algae have a greater likelihood of recovering from bleaching events. Certain coral species are able to store more energy in their cells than other species, but even corals of the same species vary in their ability to store energy.

The students constructed a Punnett square for corals that illustrates the transmission of the trait that allows the corals to live in warm water.

Coral polyps X and Y are

The students’ research indicated that one species of coral has 28 chromosomes.

Place the numbers into the table to describe the most likely number of chromosomes in coral parents and offspring during sexual reproduction.

Each number may be used once, more than once, or not at all.

The students continued their research to determine how different coral colonies interact with one another.

The students’ research indicated that corals that can survive in water over 31 degrees Celsius, degrees C31 degrees Celsius (°C) have a greater likelihood of surviving bleaching events.

If coral polyps only breed with corals that carry this temperature trait, the offspring they produce will most likely have

Part A

The research indicated that there are coral species that live much deeper in the ocean and prefer to live in cool water below 19 degrees Celsius, degrees C.19 degrees Celsius (°C).

If a cool-water coral species were moved to a shallow reef near the equator, the corals would most likely

Part B

The students modified an existing model they had made to predict how breeding between coral polyps with a trait that allows the corals to live in warm water would be transmitted.

Use evidence to explain why corals use this method of reproduction to produce offspring to form new reef colonies.

During a visit to the Maryland Zoo, a group of students observed a colony of black-tailed prairie dogs. The students decided to research prairie dogs and the North American prairie ecosystem in which they live. The students found the following food web that illustrated relationships between several organisms in the prairie ecosystem.

The students wanted to understand how the availability of resources affects population size. The students used a computer simulation, changed the number of ferrets in a prairie ecosystem and observed the population changes for three different animals and one plant. The simulation collects data every two years. The students studied an eight-year period and completed the following data tables.

The students researched other animals in the prairie that are not predators of prairie dogs to consider other types of interactions. The students organized the research into the following diagram and used it to identify these interactions as competitive or mutually beneficial to the prairie dogs in the prairie ecosystem.

• eat the shorter grass that the prairie dogs also like

• eaten by birds like burrowing owls

• reproduce in large numbers

• are active in warmer months/inactive in winter months

• eat the same type of grass as the prairie dogs

• eat the taller grass that has less nutrients than the shorter grass

• fertilize the soil with dung which helps grass grow

• roll in the dirt mounds created by prairie dogs digging tunnels to help keep biting flies away

• produce one calf each year

• live underground in burrows that have been dug out and abandoned by prairie dogs

• eat grasshoppers

• produce $\text{3-12}$ hatchlings a year

• are active in the daytime, unlike other types of owls

• may collect bison dung around burrows when nesting

The prairie food web simulation illustrates interactions among organisms that live in the prairie ecosystem.

Identify each organism in the food web as a producer or a consumer.

Place each organism into the appropriate box.

The prairie food web simulation illustrates interactions among organisms that live in the prairie ecosystem.

Which statement best describes the sources of energy for the producers and consumers in the food web?

The prairie food web simulation illustrates interactions among organisms that live in the prairie ecosystem.

The arrows in the food web represent

The prairie dog and ferret interact with one another in the prairie ecosystem simulation.

Which graph best represents the changes in the amount of grass and prairie dog population when the initial number of ferrets in the ecosystem was 140?

The prairie organisms’ interactions simulation illustrates the interactions that occur among three different organisms and the prairie dog.

The three simulations illustrate the interactions among organisms in the prairie ecosystem.

Describe how the prairie dog and bison populations will most likely change if a severe drought were to occur for a four-year period. In your description, be sure to include

• the cause of any changes to the populations

• the movement of energy within the ecosystem

• the interactions among the organisms