Evolution Flashcards
What Is Independent Assortment?
Independent assortment occurs during meiosis where the homologous chromosomes align along the equator of the cell, independent of each other. They then separate and different combinations of each are possible in the sex cells produced.
What Is Crossing Over?
Crossing over is a process that occurs during meiosis where two homologous chromosomes pair up and exchange segments of their DNA. This causes variation in the sex cells produced.
What Is Random Union Of Gametes?
Since there are so many different forms of sperm cells from a male individual and egg cells from a female individual, the resulting offspring of different combinations of these would look similar but not identical (like siblings).
What Is A Mutation?
A mutation is a permanent change to the DNA sequence. (This is the only process that may introduce new genes.)
Are All Characteristics In Humans Determined By One Gene?
No, there aren’t many examples of characteristics determined by one gene in humans and most are determined by several genes. E.g. height, weight, hair, skin colour.
What Factors Affect The Variation In A Population Of Organisms?
The environment and the genetic make-up.
What Is The Variation In Population, In Terms Of Natural Selection?
There is a variation in any population (e.g. long beak, medium beak, short beak).
What Is Environmental Selection Pressure, In Terms Of Natural Selection?
Biotic agent and abiotic agents affect the ability of organisms to survive and reproduce.
What Is Survival Of The Fittest, In Terms Of Natural Selection?
Those individuals with favourable characteristics are better adapted to that particular environment, and have a greater chance of survival.
What Is Reproduction Of The Survivors, In Terms Of Natural Selection?
Those who survive, reproduce, and pass on the gene of their favourable characteristics.
What Is Change In The Population, In Terms Of Natural Selection?
The population changes over time and has a greater proportion of individuals with favourable characteristics. The population as a whole is now better adapted to that particular environment.
What Is An Abiotic Agent?
Abiotic factors are all the non-living things that interact with an organism. For example, temperature, light, humidity, the availability of air, water, and nutrients.
What Is A Biotic Agent?
Biotic factors are all the living things that interact with an organism. For example, competition, availability of food, predators, and disease.
What Is A Species?
What Is Evolution?
