Unit A Biological Diversity: Section 4.0 Flashcards
What is extinction?
Extinction is the disappearance of every individual of a species from then entire planet
What percent of species do scientist think are extinct?
Scientists estimate that 99% of all the species that have ever existed are now extinct. Extinction is natural.
What were most mass extinctions caused by?
Catastrophic events
When was the last major environmental change?
1.8 million years ago, called the ice age
What is extirpation?
Extirpation is a local extinction or the disappearance of a species from a particular area.
What are endangered species?
Endangered species are ones that are in immediate danger of extinction or extirpation.
What are threatened species?
Threatened species are likely to become endangered if their current declines are not reversed
What are species of special concern?
Species that are of special concern are ones that are particularly vulnerable to natural events or human activities.
Overspecialization
When organisms have adaptations that suit them to only a narrow set of environmental conditions.
Why does overspecialization happen?
This probably happens because the environment that the organism inhabits remains unchanged for a very long time.
What are the natural causes of extinction?
- catastrophic events such as volcanic eruptions, floods, or fires
- lack of food due to overpopulation
- disease
Human causes of extinction and extirpation?
Habitat Destruction
Introduction of Non-Native Species
Over-Hunting
Explain habitat destruction
Construction of buildings, agricultural development, logging, and the damming of rivers all change environments. These activities are necessary to meet human needs
Explain introduction of a non-native species
When introduced species use the same resources as native species, they compete with the native species and cause the number of native species to decline, simply because there is less of everything.
Explain Over-hunting
Over-hunting was the major cause of the decline and eventual extirpation and extinction. Basically when people killed certain species until they all died
What are the effects of extinction and extirpation?
Reduced biological diversity. When an organism disappears locally or globally, many other species are affected.
May not be enough predators so you can get overpopulation.
What is artificial selection?
Artificial selection is the process of selecting and breeding individuals with desirable traits to produce offspring that have these desired traits
What is biotechnology?
The use of living things to make agricultural, industrial, or medicinal products
What was a way people practiced biotechnology?
Native peoples practiced an early form of biotechnology when they gathered seeds from the biggest and healthiest corn plants
What is a downside to biotechnology?
It takes a very long time generations
How do farmers create plant clones?
The simplest way to create a clone is by taking a cutting from a plant and growing an identical plant from the cutting.
Why would a farmer want to create a plant clone?
Because the plant has desirable traits
What is the drawback to cloning plants?
The drawback is that this ideal plant has only so many leaves that can be cut off to use as cuttings.
What way does scientist make clones?
They take cells from the desired plant and are placed in a Petri dish with all the chemicals needed. Once they develop into seedlings they are put in soil
What is artificial reproductive technology?
It refers to any artificial method of joining a male and female gamete
What are the 2 ways of artificial reproductive technology and explain both
Artificial insemination- When sperm is harvested and inserted into a female
In-vitro fertilization- Sperm and eggs are harvested and placed in a petri dish and fertilized. Then placed into cows
Explain genetic engineering
Genetic engineering refers to any technology that directly alters the DNA of an organism. Takes a gene from one organism and implants it into another organism
What some risks of cloning?
Unsuccessful pregnancies, birth defects, and deaths among clones.
What are genetic engineering risks in plants?
The plants are able to breed with weeds and then become resistant to herbicides
What are the strategies to conserve biological diversity?
Protected Areas
Restoration of Ecosystems and Species
Resource Use Policies
Controlling the Spread of Exotic Species
What is in-situ conservation?
In-situ conservation refers to the maintenance of populations of wild organisms in their functioning ecosystems. Eg protected land
What is ex-situ conservation?
Ex-situ conservation refers to the conservation of components of biological diversity outside of a natural habitat. eg. zoos