You are here:

Biology/Plz Help


QUESTION: Why are humans a difficult species to study from an evolutionary biology perspective?
 A. humans have very little genetic variation compared to other species    
 B. humans have large populations with no genetic drift    
 C. humans are too variable indicating that many forces of evolution are acting simultaneously    
 D. humans have stopped evolving due to culture    
 E. humans have high mutation rates due to nuclear waste exposure

How is human genetic variation distributed?
 A. humans on different continents carry different alleles    
 B. humans on different continents have exactly the same alleles at the exact same frequencies    
 C. humans on different continents carry a few alleles that are not shared, but mostly vary in the frequencies of alleles    
 D. humans on different continents have the exact same alleles, with rare alleles only found in isolated island populations    
 E. humans on different continents vary in perfect correlation with latitude such that more variation is found at the poles and less at the equator

Why are there so many different alleles associated with Cystic Fibrosis?
 A. migration of individuals with rare alleles has removed many variants from their source population    
 B. genetic drift is common in many populations causing only one allele to be present in each    
 C. selection on one allele that provides some resistance to hay fever has caused it to be common in some populations    
 D. mutation produces new alleles that selection cannot efficiently remove because the disease is recessive    
 E. Cystic Fibrosis is advantageous in many different environments

Reaction time is trait that varies widely among humans with medium reaction times most common and especially fast and slow times rare. Which of the following genetic causes of reaction time are most likely?
 A. reaction time is affected by a single gene with two alleles, one dominant over the other    
 B. reaction time is affected by a single gene with two alleles, one incompletely dominant over the other    
 C. reaction time is affected by many genes which act together with the environment to determine reaction time    
 D. reaction time is completely environmental reflecting the local temperature at the time of the test

Proving that a trait is under selection in humans is difficult at best. Which of the following traits has the LEAST scientific support to show that it is under selection in at least some populations?
 A. resistance to HIV infection    
 B. increased kindness in emergency situations    
 C. decreased heat loss in cold climates    
 D. ability to digest lactose (milk sugar) as an adult    
 E. increased oxygen efficiency at high altitudes

I have a policy regarding answering homework questions.. I require to first give an answer and then I will make a response.
 I must tell you however that I can see problems with these questions. They are confusing and some possible answers are ambiguous and I am unsure about the validity of the statement in question.These questions would best be answered by essay rather then multiple choice

---------- FOLLOW-UP ----------

QUESTION: My answers:
1) A
2) A
3) D
4) C
5) A

Hi again Lana
i have looked over your answers and my comments are as follows.
 1. 1 would agree with A it is the best answer although it is not completely true. It is an arbtrary statement
 2. Again A is the best answer
 3. I believe the instructor prefers D. It would make sense if mutations were a common event which they are not
 4. I would prefer B here
 5. I would select B here. increased cannot be tested.

I am curious about these questions. Is this a college class


All Answers

Answers by Expert:

Ask Experts


Walter Hintz


Science teacher for over 50 years. MSc. in biology. I can answer questions in general biology, zoology, botany, anatomy and physiology and biochemistry.


I have a MSc in biology and have been a science teacher for over 50 years. At present I am a faculty member at a college and a science consultant at seven catholic schools.

The Ohio journal of Science
Momentum-The Journal of the Catholic Education Association

©2017 All rights reserved.