evolution Flashcards
define gene
It’s a segment of DNA that contains instructions for building specific proteins or RNA molecules. Genes are passed from parents to offspring.
define allels
An allele is a variant form of a gene.
Each gene has at least two alleles.
You inherit one allele from each parent.
These alleles can be the same or different.
define genetic variation
Genetic variation refers to the differences in DNA sequences among individuals of the same species. It’s the reason why we all look different and have unique traits.
It’s a result of a sexual reproduction.
how does a new allele form?
Mutations are the primary source of new alleles.
define mutations
A mutation is a permanent alteration in the DNA sequence of a gene. It can involve changes in single nucleotides (point mutations) or larger segments of DNA (chromosomal mutations). that can occur randomly during DNA replication or due to exposure to certain environmental factors (like radiation or chemicals
define phenotypic variation
Phenotypic variation refers to the observable differences among individuals within a population in terms of their physical appearance, behavior, and other characteristics. These traits are collectively known as the phenotype.
define fitness
an organism’s ability to survive and reproduce in a particular environment. It’s a measure of reproductive success, not physical strength or athleticism.
define natural selection
“survival of the fittest”
Natural selection is the process by which organisms better adapted to their environment tend to survive and produce more offspring. This leads to the gradual evolution of populations over time.
Favorable traits are passed on to offspring - increase the frequency of advantageous alleles and reduce the frequency of disadvantageous alleles.
define evolution
Evolution is a fundamental principle in biology that represents the change in the heritable characteristics of biological populations over successive generations. This means that species change over time, and these changes are passed on to their offspring.
what are the seven properties and processes that are associated with life?
- Order: Living organisms exhibit complex organization at various levels, from atoms to molecules, cells, tissues, organs, and organisms.
- Regulation: Organisms maintain internal conditions within a stable range, a process known as homeostasis.
3.Growth and Development: Organisms increase in size and complexity over their lifespan, following specific patterns (that genes control).
- Energy Processing: Organisms acquire and use energy to perform various activities. they emit energy in the form of heat.
- Response to Stimuli: Organisms can detect and respond to stimuli in their environment.
- Reproduction: The ability to produce offspring, either sexually or asexually.
- Evolution and Adaptation: organisms adapt to their environments, ensuring survival and reproduction.
explain the endosymbiotic theory
The endosymbiotic theory suggests that some of the organelles present in eukaryotic cells, specifically mitochondria and chloroplasts, were once free-living prokaryotic organisms.
are the host cells in endosymbiosis prokaryotic or eukaryotic?
The host cell in endosymbiosis is a eukaryotic cell.
define endosymbionts
Endosymbionts are organisms that live within the body or cells of another organism.
define algae
Algae are a diverse group of photosynthetic organisms that primarily live in water. They range from microscopic single-celled organisms to large, multicellular seaweeds.
what’s the primary endosymbiosis
Primary endosymbiosis is the evolutionary process where a eukaryotic cell engulfed a prokaryotic cell, which eventually became an organelle. This event is believed to be the origin of mitochondria and then chloroplasts.
Mitochondria are thought to have originated from an engulfed aerobic bacterium.
Chloroplasts are believed to have evolved from a photosynthetic cyanobacterium.
what’s the secondary endosymbiosis
Secondary endosymbiosis is a more complex process than primary endosymbiosis. It occurs when a eukaryotic cell engulfs another eukaryotic cell that has already undergone primary endosymbiosis. it’s endosymbiosis happening twice.
what is the difference between living and non-living?
The primary distinction between living and non-living things lies in their ability to exhibit the characteristics of life.
define species
A species is the basic unit of biological classification. It is a group of organisms that can interbreed and produce fertile offspring.
define ecosystem
An ecosystem is a community of living organisms (plants, animals, and microbes) interacting with each other and their non-living environment (weather, earth, sun, soil, climate, atmosphere).
define biodiversity
Biodiversity refers to the variety of life in an ecosystem.
define population
A population is a group of individuals of the same species living in a specific area and function as a community.
define taxonomy
Taxonomy is the science of naming, describing, and classifying organisms.
what are the 3 domains of life?
Archaea: These are single-celled prokaryotic organisms that often live in extreme environments, such as hot springs, salt lakes, and deep-sea vents. They were once classified as bacteria but have distinct genetic and biochemical characteristics.
Bacteria: Another group of single-celled prokaryotic organisms, bacteria are incredibly diverse and found in almost every habitat on Earth.
Eukarya: This domain includes all organisms with eukaryotic cells, which have a nucleus and membrane-bound organelles. This domain encompasses animals, plants, fungi, and protists.