Topic 14 Flashcards
What is variation in a population?
Differences in the characteristics of individuals in a population
Variation may be due to genetic causes, environmental causes, or a combination of both.
What typically causes genetic variation within a species?
Mutations
Most mutations have no effect on phenotype; some influence it, and very few determine it.
Define evolution in the context of natural selection.
A change in the inherited characteristics of a population over time
This process may result in the formation of a new species.
How does evolution occur through natural selection?
Individuals with characteristics suited to the environment are more likely to survive and breed successfully
Their genes are then passed on to the next generation.
What is the significance of Charles Darwin’s work?
Proposed the theory of evolution based on observations from his expedition
He published ‘On the Origin of Species’ in 1859.
True or False: The theory of evolution by natural selection was immediately accepted.
False
It faced controversy and required time for acceptance due to insufficient evidence and challenges to existing beliefs.
What is a major factor contributing to the rapid evolution of bacteria?
Their fast reproduction rate
This allows mutations to produce new strains, some of which may be antibiotic resistant.
List factors that may contribute to the extinction of a species.
- Changes to the environment over geological time
- New predators
- New diseases
- New, more successful competitors
- Catastrophic events
What are fossils?
Remains of organisms from millions of years ago found in rocks
Fossils can be formed from decayed remains, mineral replacements, or preserved traces.
What is selective breeding?
The process by which humans breed plants and animals for particular genetic characteristics
It involves selecting parents, breeding them, and repeating the process over generations.
Fill in the blank: Genetic engineering involves modifying the _______ of an organism.
genome
This is done by introducing a gene from another organism.
What are genetically modified (GM) crops generally designed to achieve?
Increased yields
Characteristics may include larger fruits, disease resistance, or herbicide resistance.
Name two methods of plant cloning.
- Tissue culture
- Cuttings
What is the binomial system of classification?
A method of naming organisms using genus and species
Developed by Carl Linnaeus.
Who developed the three domain system of classification?
Carl Woese
This system includes Archaea, Bacteria, and Eukaryota.
