Master NEET Zoology with topic-wise questions. Tailored for NEET students, these questions strengthen your Biology preparation.
In a plant species that reproduces through apomixis, a mutation arises in a somatic cell that confers resistance to a fungal pathogen. What is the likelihood that this resistance trait will be passed on to the offspring?
Low, as somatic mutations are rarely heritable.
High, as apomixis bypasses meiosis and fertilization.
Dependent on whether the mutation is dominant or recessive.
Zero, as apomixis only involves the maternal gametophyte.
A researcher observes a unicellular organism reproducing asexually. The daughter cells are genetically identical except for a few minor variations. Which mechanism is MOST likely responsible for these variations?
Crossing over during mitosis
Independent assortment of chromosomes
Random mutations during DNA replication
Conjugation with another individual
Which observation MOST directly challenges the idea of a universally applicable “molecular clock” for dating evolutionary divergence?
Fossil evidence sometimes contradicts molecular clock estimates.
Mutation rates can be influenced by environmental factors.
Different genes evolve at different rates, even within the same lineage.
Horizontal gene transfer can introduce new genes into a lineage.
Darwin's finches on the Galapagos Islands exhibit diverse beak morphologies adapted to different food sources. Which of the following BEST describes the genetic mechanism underlying this diversification, assuming the ancestral finch population had limited beak variation?
Horizontal gene transfer from other bird species introduced new beak morphologies.
Hybridization between different finch species generated novel beak shapes.
Mutations in regulatory genes controlling beak development led to variations upon which natural selection acted.
Environmental factors directly induced heritable changes in beak structure.
Certain cave-dwelling organisms have lost their eyes and pigmentation over generations. While seemingly detrimental, these traits persist. Which evolutionary explanation BEST accounts for this phenomenon?
Use it or lose it: In the absence of light, vision is not beneficial, and the energy expenditure for eye development and maintenance is selected against. Similarly, pigmentation is not advantageous in a dark environment.
Bottleneck effect: A random event reduced the cave population, and the surviving organisms happened to lack eyes and pigmentation. These traits then became fixed in the population.
Founder effect: The original cave-dwelling organisms lacked eyes and pigmentation, and these traits persisted in subsequent generations.
Sexual selection: In the dark cave environment, mates are selected based on traits other than vision and pigmentation.
The evolution of insecticide resistance in insect populations is often cited as an example of natural selection. However, a counter-argument proposes that resistance pre-exists in a few individuals and simply becomes more frequent. Which observation MOST strongly refutes this counter-argument and supports the role of natural selection?
Insecticide resistance develops more rapidly in populations with high reproductive rates.
Resistant insects often exhibit reduced fitness in the absence of the insecticide.
The specific resistance mechanism, often a change in a target enzyme, arises independently in geographically separated populations exposed to the same insecticide.
The frequency of resistant insects decreases when insecticide application is stopped.
Which process is primarily responsible for the increase in the frequency of beneficial alleles in a population?
Genetic drift
Gene flow
Mutation
Natural selection
Which of the following is NOT a key factor driving evolution?
Natural selection
Genetic drift
Mutations
Static environmental conditions
Which of the following is NOT a key factor influencing the rate of evolution?
Mutation rate
Generation time
Static environmental conditions
Strength of natural selection
