Topic 4B – Diversity and Classification and Variation Flashcards
What is meiosis?
Meiosis is a type of cell division that reduces the chromosome number by half, creating four genetically diverse daughter cells (gametes).
How does meiosis contribute to genetic variation?
Meiosis introduces genetic variation through crossing over (exchange of genetic material between homologous chromosomes) and independent assortment (random distribution of chromosomes).
What is the difference between meiosis I and meiosis II?
~Meiosis I: Homologous chromosomes are separated into two daughter cells.
~Meiosis II: Sister chromatids are separated, resulting in four non-identical haploid cells.
What is a mutation?
A mutation is a change in the DNA sequence that can lead to genetic variation. Mutations can be beneficial, harmful, or neutral.
How do mutations contribute to genetic diversity?
Mutations introduce new alleles into a population, increasing genetic variation and providing a raw material for natural selection.
What is natural selection?
Natural selection is the process by which organisms with advantageous traits survive and reproduce more successfully, passing those traits to the next generation.
How does natural selection lead to evolution?
Over time, beneficial mutations accumulate in a population, leading to gradual changes in species characteristics and eventually to the formation of new species.
What is evolution?
Evolution is the change in the inherited characteristics of a population over successive generations.
How can scientists investigate selection in a population?
Scientists can investigate selection by observing changes in allele frequencies in a population over time and comparing survival and reproduction rates of different phenotypes.
What is directional selection?
Directional selection occurs when individuals with one extreme phenotype are favored, causing a shift in the population’s phenotype distribution.
What is stabilizing selection?
Stabilizing selection favors individuals with average phenotypes and selects against extremes, maintaining the status quo in the population.
What is disruptive selection?
Disruptive selection favors individuals with extreme phenotypes and selects against the average, potentially leading to two distinct groups within a population.
What is classification in biology?
Classification is the process of organizing organisms into groups based on shared characteristics and evolutionary relationships.
What is the binomial nomenclature system?
Binomial nomenclature is a system of naming species using two Latin words: the genus name (capitalized) and the species name (lowercase), e.g., Homo sapiens.
What are the main taxonomic ranks used in classification?
The main taxonomic ranks are:
* Domain
* Kingdom
* Phylum
* Class
* Order
* Family
* Genus
* Species
What is the difference between prokaryotic and eukaryotic organisms?
Prokaryotic organisms lack a membrane-bound nucleus and organelles, while eukaryotic organisms have a membrane-bound nucleus and organelles.
How does DNA technology aid in classification?
DNA technology, such as DNA sequencing and comparison of genetic markers, helps identify genetic relationships between species, improving classification accuracy.
What is phylogenetics?
Phylogenetics is the study of the evolutionary relationships among species, often using DNA sequence data to build phylogenetic trees.
What is cladistics?
Cladistics is a method of classification based on shared derived characteristics, used to construct evolutionary trees (cladograms).
What is genetic variation?
Genetic variation refers to differences in DNA sequences among individuals within a population, leading to variation in traits.
What are the two main sources of genetic variation?
~Mutations: Changes in DNA that can create new alleles.
~Recombination: The reshuffling of genes during meiosis (crossing over and independent assortment).
What is environmental variation?
Environmental variation refers to differences in traits caused by environmental factors, such as diet, climate, or lifestyle.
What is biodiversity?
Biodiversity refers to the variety of life forms in a particular habitat or on Earth, including the diversity of species, ecosystems, and genetic variation.
Why is biodiversity important?
Biodiversity is essential for ecosystem stability, resilience, and the provision of ecosystem services such as pollination, clean air, and water.
What is species diversity?
Species diversity refers to the variety of different species within a particular ecosystem or on the planet.
What is genetic diversity?
Genetic diversity refers to the variation in genetic makeup within a species, contributing to a population’s ability to adapt to environmental changes.
What are the threats to biodiversity?
Major threats include habitat destruction, climate change, pollution, overexploitation, and invasive species.
What is conservation?
Conservation is the protection and preservation of biodiversity, including the management of species, habitats, and ecosystems
What is DNA technology?
Techniques such as DNA sequencing and polymerase chain reaction (PCR) that are used to manipulate and study DNA for classification and other applications.
