
Concept explainers
Which of the following classes of muscle is/are voluntary?
a. skeletal muscle
b. cardiac muscle
c. smooth muscle
d. all of the above

Introduction:
The muscles that are controlled by the external stimulation are called as voluntary muscles. The muscles that are not under voluntary control are called as involuntary muscles.
Answer to Problem 1TYK
Correct answer:
The skeletal muscles fall under the class of voluntary muscles. The skeletal muscles make up the skeletal system of the body. It consists of long, unbranched fibers.
Explanation of Solution
Explanation/Justification for the correct answers:
Option (a) is given as skeletal muscle. The presence of sarcomeres in the muscle cell give them a striated appearance. These muscles can be controlled by the somatic motor neurons and hence, are voluntary in nature. Hence, Option (a) is correct.
Explanation for incorrect answer:
Option (b) is given as cardiac muscle. The muscles that line the walls of the heart and are responsible for pumping blood throughout the body are known as cardiac muscles. The highly branched cardiac muscles are joint end-to-end by the intercalated discs. The electrical signals flow across these intercalated discs and thus coordinate the heartbeats. The cardiac muscles are involuntary in nature as they are not controlled by external stimulation. So, it is incorrect.
Option (c) is given as smooth muscle. Organs like the lungs, blood vessels, reproductive system, urinary bladder, and digestive system are made up of smooth muscles. These muscles show no branching and taper towards the ends. The absence of sarcomeres in the cells give them a smooth appearance. The autonomous motor neurons run across these muscles and hence they are involuntary in nature. So, it is incorrect.
Option (d) is given as all the above. The smooth muscles and the cardiac muscles are involuntary in nature, therefore all of the above cannot be chosen as an option. So, it is incorrect.
Hence, options (b), (c), and (d) are incorrect.
The skeletal muscles are voluntary, whereas the smooth muscles and the cardiac muscles are involuntary in nature.
Want to see more full solutions like this?
Chapter 48 Solutions
Biological Science
- If you had an unknown microbe, what steps would you take to determine what type of microbe (e.g., fungi, bacteria, virus) it is? Are there particular characteristics you would search for? Explain.arrow_forwardavorite Contact avorite Contact favorite Contact ୫ Recant Contacts Keypad Messages Pairing ง 107.5 NE Controls Media Apps Radio Nav Phone SCREEN OFF Safari File Edit View History Bookmarks Window Help newconnect.mheducation.com M Sign in... S The Im... QFri May 9 9:23 PM w The Im... My first.... Topic: Mi Kimberl M Yeast F Connection lost! You are not connected to internet Sigh in... Sign in... The Im... S Workin... The Im. INTRODUCTION LABORATORY SIMULATION Tube 1 Fructose) esc - X Tube 2 (Glucose) Tube 3 (Sucrose) Tube 4 (Starch) Tube 5 (Water) CO₂ Bubble Height (mm) How to Measure 92 3 5 6 METHODS RESET #3 W E 80 A S D 9 02 1 2 3 5 2 MY NOTES LAB DATA SHOW LABELS % 5 T M dtv 96 J: ப 27 כ 00 alt A DII FB G H J K PHASE 4: Measure gas bubble Complete the following steps: Select ruler and place next to tube 1. Measure starting height of gas bubble in respirometer 1. Record in Lab Data Repeat measurement for tubes 2-5 by selecting ruler and move next to each tube. Record each in Lab Data…arrow_forwardCh.23 How is Salmonella able to cross from the intestines into the blood? A. it is so small that it can squeeze between intestinal cells B. it secretes a toxin that induces its uptake into intestinal epithelial cells C. it secretes enzymes that create perforations in the intestine D. it can get into the blood only if the bacteria are deposited directly there, that is, through a puncture — Which virus is associated with liver cancer? A. hepatitis A B. hepatitis B C. hepatitis C D. both hepatitis B and C — explain your answer thoroughlyarrow_forward
- Ch.21 What causes patients infected with the yellow fever virus to turn yellow (jaundice)? A. low blood pressure and anemia B. excess leukocytes C. alteration of skin pigments D. liver damage in final stage of disease — What is the advantage for malarial parasites to grow and replicate in red blood cells? A. able to spread quickly B. able to avoid immune detection C. low oxygen environment for growth D. cooler area of the body for growth — Which microbe does not live part of its lifecycle outside humans? A. Toxoplasma gondii B. Cytomegalovirus C. Francisella tularensis D. Plasmodium falciparum — explain your answer thoroughlyarrow_forwardCh.22 Streptococcus pneumoniae has a capsule to protect it from killing by alveolar macrophages, which kill bacteria by… A. cytokines B. antibodies C. complement D. phagocytosis — What fact about the influenza virus allows the dramatic antigenic shift that generates novel strains? A. very large size B. enveloped C. segmented genome D. over 100 genes — explain your answer thoroughlyarrow_forwardWhat is this?arrow_forward
- Molecular Biology A-C components of the question are corresponding to attached image labeled 1. D component of the question is corresponding to attached image labeled 2. For a eukaryotic mRNA, the sequences is as follows where AUGrepresents the start codon, the yellow is the Kozak sequence and (XXX) just represents any codonfor an amino acid (no stop codons here). G-cap and polyA tail are not shown A. How long is the peptide produced?B. What is the function (a sentence) of the UAA highlighted in blue?C. If the sequence highlighted in blue were changed from UAA to UAG, how would that affecttranslation? D. (1) The sequence highlighted in yellow above is moved to a new position indicated below. Howwould that affect translation? (2) How long would be the protein produced from this new mRNA? Thank youarrow_forwardMolecular Biology Question Explain why the cell doesn’t need 61 tRNAs (one for each codon). Please help. Thank youarrow_forwardMolecular Biology You discover a disease causing mutation (indicated by the arrow) that alters splicing of its mRNA. This mutation (a base substitution in the splicing sequence) eliminates a 3’ splice site resulting in the inclusion of the second intron (I2) in the final mRNA. We are going to pretend that this intron is short having only 15 nucleotides (most introns are much longer so this is just to make things simple) with the following sequence shown below in bold. The ( ) indicate the reading frames in the exons; the included intron 2 sequences are in bold. A. Would you expected this change to be harmful? ExplainB. If you were to do gene therapy to fix this problem, briefly explain what type of gene therapy youwould use to correct this. Please help. Thank youarrow_forward
- Molecular Biology Question Please help. Thank you Explain what is meant by the term “defective virus.” Explain how a defective virus is able to replicate.arrow_forwardMolecular Biology Explain why changing the codon GGG to GGA should not be harmful. Please help . Thank youarrow_forwardStage Percent Time in Hours Interphase .60 14.4 Prophase .20 4.8 Metaphase .10 2.4 Anaphase .06 1.44 Telophase .03 .72 Cytukinesis .01 .24 Can you summarize the results in the chart and explain which phases are faster and why the slower ones are slow?arrow_forward
- Comprehensive Medical Assisting: Administrative a...NursingISBN:9781305964792Author:Wilburta Q. Lindh, Carol D. Tamparo, Barbara M. Dahl, Julie Morris, Cindy CorreaPublisher:Cengage LearningMedical Terminology for Health Professions, Spira...Health & NutritionISBN:9781305634350Author:Ann Ehrlich, Carol L. Schroeder, Laura Ehrlich, Katrina A. SchroederPublisher:Cengage Learning
- Concepts of BiologyBiologyISBN:9781938168116Author:Samantha Fowler, Rebecca Roush, James WisePublisher:OpenStax College



