Directions: Match each sentence with the correct explanation. The action: started in the past and continues into the present repeats during a period of time from past to present occurred at an indefinite time in the past   I have always liked ice cream. Jason has taken amazing pictures. He has received many awards. He has been a photographer for the last twenty years. He has helped us see the world.

Immunological surveillance that involves immune system cells checking if body cells possess the correct population of self-proteins (major histocompatibility complex I antigens) is the job of N-K Lymphocytes.

A new autoimmune drug has been developed that has a side effect of inhibiting the adaptive immune system.  Which of the following would the drug most likely affect?

Which of the following is incorrectly paired with its location or enzyme?

The contraction of skeletal muscles plays an important role in the movement of blood in the veins or your limbs.

Directions: Match each sentence with the correct explanation. The action: started in the past and continues into the present repeats during a period of time from past to present occurred at an indefinite time in the past   We have eaten at Gino’s three times so far this week. I have eaten pizza before. Maria has had her job for six years. So far, Alice has invited 15 people to her party. They have met my parents.

Older red blood cells may be removed and destroyed in the spleen.

Directions: Complete each sentence with the words in parentheses. Use the present perfect, the present perfect continuous, or the simple past of the verb. Use contractions when possible.   _____________ (I / read) that book three times.   _____________ (you / watch) TV all day long, or did you just put it on? My ____________ (sister / finish) her driving lessons. Now she’s ready to take her driving test. ___________ (I / shop) for furniture all week, but I still need a few things.  ____________(she / start) the new job yesterday.  __________ (she / have) several interviews with a lab researching global warming.

_________ contributes to the adaptive immune response through the production of antibodies.

Directions: Fill in the simple past tense and past participle of each verb. Present Simple Past Past Participle write do give think hear