Concept explainers
The experiments with nutritional mutants in Neurospora by Beadle and Tatum provided evidence that
a. bread mold can be grown in a lab on minimal media.
b. X-rays can damage DNA.
c. cells need enzymes.
d. genes specify enzymes.

Introduction:
To identify the working nature of genes, scientists from all over the world conducted various experiments. The results revealed by them include, the functions controlled by the genes and the enzymes specified by the genes.
Answer to Problem 1U
Correct answer:
The experiments with nutritional mutants in Neurospora by Beadle and Tatum provided evidence that genes specify enzymes. Therefore, option d. is correct.
Explanation of Solution
Reason for the correct statement:
Beadle and Tatum showed that genes specify enzymes. In neurospora, each enzyme of the arginine pathway was encoded by a separate gene. The mutant species of neurospora were unable to synthesize arginine. Beadle and Tatum found that specific enzymes controlled by specific genes were absent in the mutant neurospora. They proposed the one gene-one enzyme hypothesis.
Option d. is given as "genes specify enzymes".
As, “the experiments with nutritional mutants in Neurospora by Beadle and Tatum provided evidence that genes specify enzymes”, it is the right answer.
Hence, the option d. is correct.
Reasons for the incorrect statements:
Option a. is given as “bread mold can be grown in a lab on minimal media”.
In the experiments conducted by Beadle and Tatum, bread mold was grown to determine the enzymes specific for the growth. So, it is a wrong answer.
Option b. is given as “X-rays can damage DNA”.
The experiments conducted by Beadle and Tatum to determine the limiting factors for specific enzymes and not to determine what X-rays do to the DNA. So, it is a wrong answer.
Option c. is given as “cells need enzymes”.
The experiments conducted by Beadle and Tatum were performed to determine the limiting factors, which control synthesis of enzymes responsible for specific functions. So, it is a wrong answer.
Hence, the options a., b., and c. are incorrect.
The experiments with nutritional mutants in Neurospora by Beadle and Tatum provided evidence that genes specify enzymes.
Want to see more full solutions like this?
Chapter 15 Solutions
BIO 1406/07 W/CONNECT/LM NEW >IC<
- Ch.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_forwardCh.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_forward
- What is this?arrow_forwardMolecular 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_forward
- Molecular 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_forwardMolecular 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_forward
- Stage 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_forwardCan you circle a cell in the different stages of mitosis? 1.prophase 2.metaphase 3.anaphase 4.telophase 5.cytokinesisarrow_forwardWhich microbe does not live part of its lifecycle outside humans? A. Toxoplasma gondii B. Cytomegalovirus C. Francisella tularensis D. Plasmodium falciparum explain your answer thoroughly.arrow_forward
- Concepts of BiologyBiologyISBN:9781938168116Author:Samantha Fowler, Rebecca Roush, James WisePublisher:OpenStax CollegeBiology: The Dynamic Science (MindTap Course List)BiologyISBN:9781305389892Author:Peter J. Russell, Paul E. Hertz, Beverly McMillanPublisher:Cengage LearningPrinciples Of Radiographic Imaging: An Art And A ...Health & NutritionISBN:9781337711067Author:Richard R. Carlton, Arlene M. Adler, Vesna BalacPublisher:Cengage Learning
- Understanding Nutrition (MindTap Course List)Health & NutritionISBN:9781337392693Author:Eleanor Noss Whitney, Sharon Rady RolfesPublisher:Cengage LearningHuman Heredity: Principles and Issues (MindTap Co...BiologyISBN:9781305251052Author:Michael CummingsPublisher:Cengage Learning




