How cell parts work together to make and ship a protein

Grade 9 Science Worksheet - Challenge Me

Circle the best answer.

1. Read this first

   Use the table

   Cell cutaway (animal cell, model, not to scale). Letter A marks the rough ER (the flat folded sacs studded with tiny dots, joined to the wall of the large round body). Letter B marks the transport vesicle (a small bubble between the dotted sacs and the stack of curved smooth sacs). Letter C marks the Golgi apparatus (the stack of curved smooth sacs, away from the dotted sacs). Route in order: nucleus, nuclear pore, rough ER, transport vesicle, Golgi apparatus, secretory vesicle, plasma membrane. Pulse-chase card, read about only. Where most of the label is found (model data)

   cell	at 20 minutes	at 60 minutes
   normal cell	Golgi apparatus	outside the cell
   changed cell	transport vesicles	transport vesicles

2. 1.

   Ari sees that in the changed cell one job fails. Use the cutaway and the card. Which job fails?

   • The nucleus is not building the protein, so no label moves on
   • The Golgi apparatus is not building the protein from amino acids
   • Vesicles are not delivering protein from the rough ER to the Golgi
   • Secretory vesicles are not fusing with the plasma membrane at the cell edge
3. 2.

   Bo follows proteins M and K, which travel the same route. What does the card show about the end of it?

   • Both leave the Golgi in vesicles; M is released and K joins the membrane
   • The vesicle carrying K stays fixed at the cell edge as a permanent part of the cell
   • K skips the Golgi and uses no vesicle to reach the membrane
   • K is built in the Golgi apparatus, which is why it joins the membrane
4. 3.

   Esme compares three gland cells with the route in the cutaway. Which statement does the card support?

   • Release is highest in Z, since Z has the most rough ER
   • Release depends on the Golgi apparatus, since the Golgi builds the protein
   • More rough ER and Golgi go with more release, as the route uses both
   • Release depends on the rough ER, since each part does its job on its own
5. 4.

   Jun sees no label outside the cell at 20 minutes, though the protein was made by 5 minutes. Why does this fit the route?

   • The nucleus holds the finished protein until 60 minutes, then releases it
   • A vesicle is a fixed part that stores the protein until 60 minutes
   • The protein is still on its way, passing several parts before release
   • The rough ER works alone, so it needs 60 minutes to send it out
6. 5.

   Kira sees that the changed cell makes the protein but releases almost none. Which explanation fits the card?

   • Transport vesicles are not delivering protein from the rough ER
   • The Golgi apparatus is not building enough of the protein to send on
   • The nucleus is holding the finished protein inside and not releasing it
   • Vesicles are not carrying protein from the Golgi to the membrane
7. 6.

   The count of vesicles near the membrane falls while protein outside rises. Luz asks where the vesicles went. Which explanation fits?

   • They fused with the plasma membrane and released the protein
   • They are permanent parts, so they moved out of view into the cytoplasm
   • They returned to the rough ER to pick up more protein
   • They were used up making ATP, the cell’s energy molecule

8. Use the table

   Pulse-chase card, read about only. Where the label was found (model data)

   minutes after labeling	most label found in
   5	rough ER
   25	Golgi apparatus

9. 7.

   Noah's class saw label in the Golgi apparatus at 25 minutes and concluded the Golgi built the protein. What is the flaw?

   • No flaw: label found in a part shows that part built the protein
   • The Golgi cannot be tested, since each part works alone
   • The label was in the rough ER first, so the protein reached the Golgi already built
   • The label should have been in the nucleus first, since the nucleus builds proteins

10. Rough ER counted in one slice of each cell (model data)

    cell	rough ER sacs
    gland cell	44
    muscle cell	10

11. 8.

    Pia's class counted rough ER in one gland cell and one muscle cell, then said every gland cell has more. Which flaw is in the conclusion?

    • Only one cell of each type was counted, so more cells are needed
    • Rough ER cannot be counted, because it is too small to see
    • The counts do not matter, because each part works alone and the cell type cannot change them
    • The nucleus was not counted, and the nucleus builds the proteins
12. 9.

    Tala says the Golgi apparatus could still pack proteins for release if the rough ER stopped making them. Which response is best?

    • Agree: the Golgi apparatus builds its own proteins to pack
    • Disagree: the vesicles are fixed parts that would keep delivering protein
    • Agree: each part works alone, so the Golgi needs no protein from the rough ER
    • Disagree: the Golgi packages proteins that arrive from the rough ER
13. 10.

    Cell cutaway (plant cell, model, not to scale). Zee says a leaf cell has chloroplasts (A), so its mitochondria (B) are not needed. Which response fits?

    • Disagree: mitochondria make the sugar that chloroplasts use
    • Disagree: mitochondria use the chloroplasts’ sugar to provide ATP
    • Agree: plant cells have no mitochondria
    • Agree: the chloroplast works alone and supplies the cell’s energy by itself