The ultimate source of allelic variations is:
1. Genetic recombinations
2. Mutation
3. Genetic drift
4. Natural selection
People who carry an allele for normal haemoglobin and an allele for sickle cell are resistant to malaria. They are examples of:
1. heteozygote advantage
2. extreme diploidy
3. outbreeding
4. recessive superiority
The unit of evolution is now known to be the:
1. individual
2. family
3. population
4. species
The struggle for existence is a consequence of:
(1) Each organism leaving more organisms than needed to replace itself
(2) Innate competitive tendencies
(3) The inevitable difficulty of coping with climatic conditions
(4) Territories and dominance hierarchies
Darwin believed that a giraffe has a long neck because:
1. a creator designed it that way
2. catastrophes eliminated short neck forms
3. its ancestors stretched their necks to get food
4. ancestral giraffes with longer necks got more food and left more surviving off-springs.
In a population of red (dominant) and white flowers, the flowers of red flowers is 91%. What is the frequency of the red allele?
1. 9%
2. 30%
3. 91%
4. 70%
In a sympatric speciation, there is:
1. | geographical isolation between groups of population |
2. | no geographical isolation between groups of population |
3. | reproductive isolation of a subpopulation in the midst of the parent population |
4. | geographical isolation bout no reproductive isolation |
In modern terms, selection refers to :
1. Inheritance of dominant characters
2. differential reproduction
3. a decrease in allele frequency in a population
4. differences in the contribution of various genotypes to the next generation
In genetic drift, the term "genetic bottleneck" means:
1. reduction in allele frequencies or richness
2. random change in allele frequency by chance alone
3. sudden increase in the number of individuals
4. reproductive isolation of the population
What is genetic equilibrium?
(1) When all the alleles of a gene are present in a population in equal frequencies
(2) When the number of heterozygotes in a population are equal to the number of either of the homozygote
(3) When the number of heterozygotes in a population are equal to the number of either of the homozygote
(4) When the frequency of particular genes or alleles remain constant in a population through generations