In the Search to Discover the Agents That Cause Mad $\bullet$

question 49

Multiple Choice

In the search to discover the agents that cause mad cow disease,scrapie in sheep,and CJD and kuru in humans,diseased brain tissues were passed through a fine filter to remove bacteria.The filtrate was still infectious,indicating that something smaller than bacteria,either viruses or organic molecules,must be the causative agent.If a virus was responsible for these brain diseases,then the infectious agent would contain either RNA or DNA.Other possibilities were that the agent was a carbohydrate,fat,or protein.Tissue filtrates were treated with agents that destroyed just one of these chemicals and then injected into a healthy animal,with the results as follows.What is the infectious agent? $\bullet$ Amylase digests carbohydrates; tissue filtrate still infects healthy test animal.
$\bullet$ Lipase digests fats; tissue filtrate still infects healthy test animal.
$\bullet$ Formaldehyde and/or heat denatures DNA and RNA; tissue filtrate still infects healthy test animal.
$\bullet$ Trypsin digests protein; tissue filtrate does not infect healthy test animal.

• A)carbohydrate
• B)fat
• C)protein
• D)DNA or RNA
• E)Could be carbohydrate,fat,or DNA or RNA but not protein.

---

Definitions:

Puberty

The stage of adolescence in which an individual becomes physically capable of sexual reproduction.

Sexual Maturity

Sexual maturity is the stage in an organism's life cycle when it has reached the ability to reproduce, characterized by the development of secondary sexual characteristics and reproductive organs.

Puberty

The phase in human development during which a child matures sexually and becomes capable of reproduction.

Adolescence

The period of maturation involving both mental and physical changes, occurring from puberty to the age of legal responsibility.