What is the irony in the husband's refusal to lock the door

  Strong winds enter the house through the open door, and the husband tells the wife to "Gae [go] out and bar the door." 

She, in summary, tells him to forget it.  She's the one who is busy working, not him. 

They make a pact that whoever speaks first will be the one to have to close and bar the door.  They are both stubborn, and stubbornness is really what the poem is about.  You could say stubbornness is the theme of the poem.

1. a host loses nutrients to a parasite

2. a parasite only benefits when the host is alive (cause if the host dies the parasite dies with it )

3. producers to consumers

4. the tapeworm is a parasite

5. they convert energy from the sun (photosynthesis)

6. sunflower-robin (i think im 80% sure)

7. producer

8. consumer

9. prey

10. fresh water snails ( cause the green algea is the producer and the snails are the primary consumers and the small fish consumer so is the big fish)