Evolution and ecology

Written by Dr. Hira Salman (Biology)

MDCAT · Biology · 6 questions

Name: ____________________ Date: ____________

The theory of evolution by natural selection was proposed by Alfred Wallace and:
- A Louis Pasteur
- B Robert Hooke
- C Charles Darwin
- D Gregor Mendel
Roughly what percentage of energy is passed on from one trophic level to the next?
- A 1%
- B 50%
- C 10%
- D 90%
The human arm and a whale's flipper are examples of:
- A Vestigial structures
- B Convergent traits
- C Homologous structures
- D Analogous structures
In a population in Hardy-Weinberg equilibrium, q squared is 0.04. What is the frequency of heterozygotes (2pq)?
- A 0.32
- B 0.64
- C 0.96
- D 0.16
Nitrogen-fixing bacteria in the root nodules of legumes belong to the genus:
- A Escherichia
- B Rhizobium
- C Streptococcus
- D Nitrosomonas
Which of these is a producer in a food chain?
- A Rabbit
- B Hawk
- C Grass
- D Fungus

Answer key

1. C, 2. C, 3. C, 4. A, 5. B, 6. C

Darwin and Wallace presented the idea together in 1858. Darwin set it out in full in On the Origin of Species.
Most energy is lost as heat and in life processes, so only about 10% reaches the next level.
They have the same basic bone plan from a common ancestor but do different jobs, which makes them homologous.
q = 0.2, so p = 0.8. Then 2pq = 2 x 0.8 x 0.2 = 0.32.
Rhizobium lives in root nodules and turns nitrogen gas into ammonia that the plant can use.
Producers make their own food by photosynthesis. Grass is a producer, while rabbits and hawks are consumers and fungi are decomposers.