Genetics I
In a population, which individuals are most likely to survive and reproduce? A) The individuals who are best adapted to the environment. B) The largest individuals in the group. C) The individuals who can catch the most prey. D) The individuals who grow the most rapidly.
A
What is 'selection pressure'?
Any factor that affects the survival of the organisms. Eg predators, disease or environment.
Which of the following plants is the most fit? A) a plant with deep roots B) a plant with large leaves C) a plant with large flowers D) Fitness can't be determined without reference to the environment.
D
A city was intensively sprayed with DDT to control houseflies. The number of houseflies was immediately greatly reduced. Each year thereafter, the city was sprayed again, but the flies gradually increased in numbers until 10 years later, when they were almost as abundant as they were when the control program began. Which of the following most likely explains this? A) Flies from other areas moved in and replaced the ones killed by DDT. B) The few flies that were affected by DDT but survived developed antibodies to DDT, which they passed on to their descendants. C) The DDT caused new mutations to occur in the surviving flies, resulting in resistance to DDT. D) The DDT killed most flies. The few that were already naturally resistant survived and passed this resistance on to their offspring.
D
How many alleles do you need for dominant traits to express themselves?
Dominant traits need one single allele to express themselves.
What is the difference between artificial and natural selection?
Artificial selection - when people select plants or animals for breeding based on desirable traits. natural selection - when animals and plants are selected for fitness (=adaptations) by nature.
Your friend was diagnosed with strep throat 2 months ago. She was treated with antibiotics for 10 days, but 2 weeks after treatment, the symptoms returned. She was given a different antibiotic and her symptoms improved again, initially, but then got worse. What is happening? A) Your friend has taken antibiotics so long that she has become tolerant to them, making them ineffective. B) Exposure to antibiotics has caused each individual bacterial cell to evolve resistance to the antibiotics. C) Your friend was originally infected with some bacteria that were resistant to these two antibiotics and the bacteria multiplied. D) Your friend probably doesn't have a bacterial infection. There must be some other reason for her symptoms.
C
What does the term 'carrier' mean?
Carrier means to carry the recessive allele and not express it.
An appendix is an example of this.
What is a vestigial organ.
Name two different types of evidence that support evolution?
The fossil record, homologous structures, vestigial organs, biogeography, biological molecules (esp. DNA), comparative embryology.
After a rapid change in climate, one population of bird quickly adapts to the change, but others in the area do not. What could you conclude about the quickly adapting population? A) They had a greater need to evolve than the other population. B) They already had some alleles in their genome that were adaptive in the new environment. C) They reproduced more slowly than the non-adapting population. D) They had a higher rate of mutation than the other population.
B