8th Grade Science Final Review

Which statement correctly describes a relationship between two human body systems?

• The digestive system absorbs nutrients which are transported by the nervous system.

• The digestive system absorbs nutrients which are transported by the circulatory system.

• The circulatory system exchanges gases which are transported by the nervous system.

• The circulatory system exchanges gases which are transported by the digestive system.

Which statement best describes how the circulatory system and respiratory system can work together?

• Toxins are removed from the bloodstream by the liver.

• The stomach signals for the production of gastric juices.

• Food molecules are transported to the organs of the body.

• Gases are exchanged between the lungs and blood vessels.

Some students are taking part in a community running race. Five minutes into the race, what happens in the students' circulatory system?

• The heart pumps more blood to the legs.

• The muscles start to tighten.

• Fluids pour into the stomach.

• The lungs need more air.

Research has led scientists to conclude that fevers help the human body fight infection by elevating body temperatures and causing parts of the immune system to work better.

• A. Fevers are a disruption of homeostasis.

• B. Fevers should immediately be treated with medication.

• C. Fevers are a necessary part of maintaining homeostasis.

• D. Fevers are rarely caused by bacterial infections.

Which of your body systems lets you know when water is hot?

• nervous system

• respiratory system

• circulatory system

• skeletal system

Mitosis and meiosis are processes by which animal and plant cells divide. Which statement best describes a difference between mitosis and meiosis?

• Meiosis is a multi-step process.

• Mitosis occurs only in eukaryotic cells.

• Meiosis is used in the repair of an organism.

• Mitosis produces genetically identical daughter cells.

If an organism is known to have 38 chromosomes in each body cell, how many chromosomes will each new gamete have after meiosis?

• 2 chromosomes

• 19 chromosomes

• 38 chromosomes

• 76 chromosomes

Before mitosis begins, which happens before the nucleus starts dividing?

• The cytoplasm separates.

• The DNA replicates.

• The sister chromatids separate.

• The homologous chromosomes cross over.

How is natural selection in the evolution of long necks in giraffes best explained?

• Shorter-necked giraffes were killed by long-necked giraffes.

• Giraffe necks grew longer because of the bone structure of the animals.

• Giraffes with longer necks survived because they were better suited to the environment.

• Long-necked giraffes mated only with other long-necked giraffes.

In which of the following ways does the respiratory system help to maintain homeostasis during exercise?

• Reserves of oxygen are built up in the alveoli.

• The pharynx supplies glucose so that the muscles can produce ATP.

• Breathing rate is increased to exchange oxygen and carbon dioxide more rapidly.

• The lungs release hemoglobin so that the blood can carry more oxygen to tissues.