Skip to ContentGo to accessibility page
OpenStax Logo
Biology

Review Questions

BiologyReview Questions

Review Questions

5.

What property prevents the ligands of cell-surface receptors from entering the cell?

  1. The molecules bind to the extracellular domain.
  2. The molecules are hydrophilic and cannot penetrate the hydrophobic interior of the plasma membrane.
  3. The molecules are attached to transport proteins that deliver them through the bloodstream to target cells.
  4. The ligands are able to penetrate the membrane and directly influence gene expression upon receptor binding.
6.

The secretion of hormones by the pituitary gland is an example of _______________.

  1. autocrine signaling
  2. paracrine signaling
  3. endocrine signaling
  4. direct signaling across gap junctions
7.

Why are ion channels necessary to transport ions into or out of a cell?

  1. Ions are too large to diffuse through the membrane.
  2. Ions are charged particles and cannot diffuse through the hydrophobic interior of the membrane.
  3. Ions do not need ion channels to move through the membrane.
  4. Ions bind to carrier proteins in the bloodstream, which must be removed before transport into the cell.
8.

Endocrine signals are transmitted more slowly than paracrine signals because ___________.

  1. the ligands are transported through the bloodstream and travel greater distances
  2. the target and signaling cells are close together
  3. the ligands are degraded rapidly
  4. the ligands don't bind to carrier proteins during transport
9.

Where do DAG and IP3 originate?

  1. They are formed by phosphorylation of cAMP.
  2. They are ligands expressed by signaling cells.
  3. They are hormones that diffuse through the plasma membrane to stimulate protein production.
  4. They are the cleavage products of the inositol phospholipid, PIP2.
10.

What property enables the residues of the amino acids serine, threonine, and tyrosine to be phosphorylated?

  1. They are polar.
  2. They are non-polar.
  3. They contain a hydroxyl group.
  4. They occur more frequently in the amino acid sequence of signaling proteins.
11.

What is the function of a phosphatase?

  1. A phosphatase removes phosphorylated amino acids from proteins.
  2. A phosphatase removes the phosphate group from phosphorylated amino acid residues in a protein.
  3. A phosphatase phosphorylates serine, threonine, and tyrosine residues.
  4. A phosphatase degrades second messengers in the cell.
12.

How does NF-κB induce gene expression?

  1. A small, hydrophobic ligand binds to NF-κB, activating it.
  2. Phosphorylation of the inhibitor Iκ-B dissociates the complex between it and NF-κB, and allows NF-κB to enter the nucleus and stimulate transcription.
  3. NF-κB is phosphorylated and is then free to enter the nucleus and bind DNA.
  4. NF-κB is a kinase that phosphorylates a transcription factor that binds DNA and promotes protein production.
13.

Apoptosis can occur in a cell when the cell is ________________.

  1. damaged
  2. no longer needed
  3. infected by a virus
  4. all of the above
14.

What is the effect of an inhibitor binding an enzyme?

  1. The enzyme is degraded.
  2. The enzyme is activated.
  3. The enzyme is inactivated.
  4. The complex is transported out of the cell.
15.

Which type of molecule acts as a signaling molecule in yeasts?

  1. steroid
  2. autoinducer
  3. mating factor
  4. second messenger
16.

Quorum sensing is triggered to begin when ___________.

  1. treatment with antibiotics occurs
  2. bacteria release growth hormones
  3. bacterial protein expression is switched on
  4. a sufficient number of bacteria are present
PreviousNext
Order a print copy
Citation/Attribution
Reuse and redistribution of this content in digital or print format:
  • This book may not be used in the training of large language models or otherwise be ingested into large language models or generative AI offerings without OpenStax's prior written permission.
  • This book uses the Creative Commons Attribution License, which means that you can reuse and modify the material only for noncommercial purposes, must attribute OpenStax, and must distribute any derivative works under the same license.
  • Any commercial printing of this textbook, including using a local or custom printer, must be approved by OpenStax, and proper citation provided.
  • OpenStax-copyrighted images, activities, assessments, and similar components of this book are subject to the same licensing – CC-BY-NC-SA. They can be used for noncommercial purposes with attribution. Commercial use requires permission.
  • Permission requests: Anyone who intends to incorporate this content (including text, images, and other components) into large language models, use it in AI offerings, use it commercially (including in print), and/or has questions about another use case is welcome to complete our reuse request form.
Attribution information
  • If you are redistributing all or part of this book in a noncommercial print format, then you must include on every physical page the following attribution:

    Access for free at https://openstax.org/books/biology/pages/1-introduction

  • If you are redistributing all or part of this book in a noncommercial digital format, then for every page that includes OpenStax content, you must license the derivative work under the same CC-BY-NC-SA license as the original, and include on every digital page view the following attribution:

    Access for free at https://openstax.org/books/biology/pages/1-introduction

Citation information

The information below includes the information needed to generate citations in most major styles (APA, MLA, etc.); you must reformat and organize the information as needed to fit the requirements of the style. Use the information below to generate a citation. We recommend using a citation tool such as this one.

© Feb 14, 2022 OpenStax. Textbook content produced by OpenStax is licensed under a Creative Commons Attribution License. The OpenStax name, OpenStax logo, OpenStax book covers, OpenStax CNX name, and OpenStax CNX logo, and Rice University name, and Rice University logo trademarks, or wordmarks are not subject to the Creative Commons license and may not be reproduced without the prior and express written consent of Rice University.