Biology - Chapter 17 Flashcards
Ecology
The branch of biology dealing with the relations and interactions between organisms and their environment, including other organisms.
Biological Evolution
simply put, is descent with modification. This definition encompasses small-scale evolution (changes in gene frequency in a population from one generation to the next) and large-scale evolution (the descent of different species from a common ancestor over many generations).
Coevolution
WHen two species evolve together and in each other’s favours
Natural Selection
The theory holding that competition exists within species, determining which species live to have offspring, and pass their traits onto those offspring
Stabilizing Selection
When selection pressures favour the average form of the trait.
Directional Selection
When selection pressures favour one extreme of the trait distribution. Giraffe and moth.
Disruptive Selection
In disruptive selection, selection pressures act against individuals in the middle of the trait distribution.Grey-white- Grey-white Rabbits.
Artificial Selection
Selection by humans for desired traits. Also called domestication or breeding. cattle breeding, crop breeding.
Sexual Selection
The selection of traits based on their role in courtship and mating.
Choice
In sexual selection, the competition for attention from the opposite sex.
Contest
In sexual selection, fights or aggressive displays between same-sex individuals of the same species; contests usually determine possession of territory or mates.
Trait
A particular characteristic of an individual plant or animal.
Fitness
The probability that an individual will contribute its genes to the next generation.
Morphs
The different physical forms a trait may have. Long necks and short necks are examples of morphs.
Polymorphic
A trait that exists in several different morphs is polymorphic.
Species
The lowest taxonomic rank, and the most basic unit or category of biological classification. An individual belonging to a group of organisms (or the entire group itself) having common characteristics and (usually) are capable of mating with one another to produce fertile offspring.
Supplement
A species is given a two-part name: the generic name and the specific name (or specific epithet). For example, Allium cepa (commonly known as onion).
Population
A group of organisms of one species that interbreed and live in the same place at the same time (e.g. deer population).
Gene pool
All genes or their different set of alleles present in interbreeding population or collective genetic information of a group of organisms.
Allele Frequency
The commonness of the occurring of a particular allele in a population.
Genetic drift
Genetic drift describes random fluctuations in the numbers of gene variants in a population.
Organism
: Living things that are capable of reacting to stimuli, reproduction, growth, and homeostasis. Supplement Plants, animals, fungi and microorganisms are examples of organisms. They all consist of monomeric units called cells. Some organisms may function independently or singly (unicellular) whereas others may form many units (multicellular) divided into specialized tissues and organs. Based on cell type, organisms may be divided into prokaryotes and eukaryotes.
Abiotic factors
are nonliving environmental factors that can affect the organisms in ecosystems. Examples of abiotic factors are light intensity, soil moisture level, soil pH, temperature.
Biotic Factors
are interactions associated with living organisms Examples of biotic factors are competition for environmental resources, grazing, parasitism (where one organism, the parasite, benefits from harming another organism, the host).