Evolution Grade 12 Life Sciences Questions and Answers Pdf. Human evolution is the evolutionary process within the history of primates that led to the emergence of Homo sapiens as a distinct species of the hominid family that includes all the great apes.
This process involved the gradual development of traits such as human bipedalism, dexterity, and complex language, as well as interbreeding with other hominins (a tribe of the African hominid subfamily), indicating that human evolution was not linear but weblike
Grade 12 Evolution Questions and Answers Pdf
Questions Based on Evolution Terminologies for Grade 12
Below are some questions and answers based on the given terms and definitions related to evolution for Grade 12:
Q1: What is an Acquired Characteristic? A1: An acquired characteristic is a characteristic that an offspring is not born with but develops or is acquired through the course of its lifetime. It’s a characteristic not controlled by a gene.
Q2: How does Artificial Selection or Selective Breeding work? A2: Artificial selection or selective breeding involves the breeding of organisms over many generations in order to achieve a desirable phenotype.
Q3: What is Biodiversity? A3: Biodiversity refers to the variety of plant and animal species on Earth.
Q4: How is Biological Evolution defined? A4: Biological evolution refers to any genetic change in a population that is inherited over several generations.
Q5: What does Extant mean? A5: Extant means still in existence or surviving.
Q6: What is the Out of Africa Hypothesis in Human Evolution? A6: The Out of Africa Hypothesis is a theory related to human evolution that emphasizes the origin of modern humans in Africa before migrating to other continents.
Q7: What are Homologous Structures? A7: Homologous structures pertain to the structures that show similar morphology and anatomy but have different functions. They are believed to have developed from a common ancestor.
Q8: What is a Mutation? A8: A mutation is a sudden change in the sequence or order of nitrogenous bases of a nucleic acid.
Q9: How does Natural Selection work? A9: Natural selection is the process by which organisms best suited to survival in the environment achieve greater reproductive success, thereby passing advantageous characteristics onto future generations.
Q10: What is a Transitional Fossil? A10: A transitional fossil shows intermediate characteristics between two genera/species. It has characteristics common to both the ancestor species and the descendant species that follows.
Q11: What is Biotechnology? A11: Biotechnology is the use of biological processes, organisms, or systems to improve the quality of human life.
Q12: How does Continuous Variation differ from Discontinuous Variation? A12: Continuous variation refers to variation within a population in which there is a range of intermediate phenotypes. Discontinuous variation, on the other hand, is the type of variation in a population with no intermediate phenotypes.
Q13: What leads to Extinction of a species? A13: Extinction is the permanent disappearance of a species from Earth, which can result from various factors like environmental changes, loss of habitat, disease, predation, or competition.
Q14: What does the term “mya” stand for? A14: “mya” stands for million years ago, a unit of time used in geological and paleontological contexts.
Q15: Explain the term Phenotype. A15: The phenotype is the external, physical appearance of an organism. The phenotype is determined by the genotype.
Q16: What are Useful Mutations? A16: Useful mutations can be advantageous, as they may confer benefits to the organism, enhancing its ability to survive, reproduce, or adapt to its environment.
Q17: What is meant by a Common Ancestor? A17: A common ancestor refers to an ancestor that two or more descendants have in common.
Q18: Explain the Theory of Evolution. A18: The Theory of Evolution is regarded as a scientific theory since various hypotheses relating to evolution have been tested and verified over time. It describes the processes that have transformed life on Earth from its earliest forms to the vast diversity that characterizes it today.
Q19: How is a Gene defined? A19: A gene is a segment of DNA or a chromosome that codes for a characteristic.
Q20: What is the Study of Fossils called? A20: The study of fossils is called Palaeontology.
Questions and Answers based on Darwin’s theory of evolution
Here are some questions and answers based on Darwin’s theory of evolution by natural selection, as well as the differences between natural and artificial selection:
Q1: According to Darwin’s theory, why is there variation amongst offspring? A1: Darwin’s theory recognizes that there is a great deal of variation amongst offspring, which arises from genetic diversity and mutations, allowing some to have favourable characteristics while others may not.
Q2: What happens to organisms with unfavourable characteristics according to Darwin’s theory? A2: According to Darwin’s theory, organisms with unfavourable characteristics, which make them less suited to their environment, may die off, especially when there is a change in environmental conditions or competition.
Q3: How are favourable characteristics passed on to the next generation? A3: In Darwin’s theory of natural selection, organisms that survive due to favourable characteristics reproduce and pass on the allele for the favourable characteristic to their offspring, leading to a higher proportion of individuals with that trait in the next generation.
Q4: How does natural selection differ from artificial selection in terms of the selective force? A4: In natural selection, the environment or nature is the selective force, determining which traits are favourable for survival. In artificial selection, humans represent the selective force, choosing specific traits to propagate.
Q5: In what context does natural selection occur, and how does this compare to artificial selection? A5: Natural selection occurs within a species, with selection in response to suitability to the environment. Artificial selection may involve one or more species (as in crossbreeding) and is driven by human needs.
Q6: How do natural selection and artificial selection differ in their goals? A6: Natural selection aims to promote traits that enhance an organism’s ability to survive and reproduce in its natural environment. Artificial selection, on the other hand, focuses on traits that satisfy human needs or desires, such as in agriculture or pet breeding.
Q7: What is the ultimate result of natural selection, as described by Darwin? A7: The ultimate result of natural selection is the adaptation and evolution of species, where favourable characteristics become more common in a population over generations, shaping the species to be more suited to its environment.
Q8: How does competition play a role in Darwin’s theory of natural selection? A8: In Darwin’s theory, competition among individuals for limited resources is a driving force. Organisms with favourable characteristics have a competitive edge, allowing them to survive, reproduce, and pass those traits to the next generation.
Q9: What’s the significance of the environment in natural selection? A9: In natural selection, the environment acts as the selective force. Organisms that are best suited to the environment survive and reproduce, while those less suited may die off, leading to evolutionary changes in the population over time.
Q10: How does artificial selection lead to the development of new breeds or varieties? A10: Through artificial selection, humans selectively breed organisms with desirable traits, often over several generations. This focused selection leads to the development of new breeds or varieties that exhibit those specific traits.
Q11: Why do organisms with unfavourable characteristics die according to Darwin’s theory? A11: Organisms with unfavourable characteristics are less suited to their environment, which may lead to their inability to compete for resources, survive environmental changes, or escape predators. Consequently, they may die off.
Q12: Can artificial selection occur across different species? If so, how? A12: Yes, artificial selection can occur across different species, especially in crossbreeding. Humans may selectively breed organisms from different species to produce hybrids that possess desired traits from both species.
Q13: How do favourable characteristics become more common in a population through natural selection? A13: Favourable characteristics become more common through natural selection as organisms possessing these traits are more likely to survive, reproduce, and pass the traits to their offspring. Over generations, the proportion of individuals with these characteristics increases in the population.
Q14: How does Darwin’s theory of natural selection explain the adaptation of species? A14: Darwin’s theory explains adaptation as a process where favourable traits that enhance survival and reproduction become more common in a population over time. This leads to the species becoming better suited to its environment.
Q15: What ethical considerations might arise from artificial selection? A15: Artificial selection may raise ethical considerations related to genetic diversity, animal welfare, and environmental impact. The focused breeding for specific traits might lead to unforeseen consequences, such as health problems in the organisms or ecological imbalances.
Q16: How is Darwin’s theory of natural selection supported by modern science? A16: Modern science, including genetics and molecular biology, supports Darwin’s theory by providing evidence of genetic variation, mutations, and the mechanisms by which traits are inherited, all of which underlie the process of natural selection.