Environmental Science A - Unit 4 Exam Flashcards

Questions and Answers

Which statement best describes natural selection?

It is the process by which populations of living organisms adapt and change.

Which option describes a condition required for natural selection to occur?

Production of more offspring than can survive.

How does genetic variation help individuals in a population?

It increases the chances of survival and reproduction in a changing environment.

What best defines the fitness of an organism? (Select all that apply)

Ability to reproduce Signup and view all the answers

How will natural selection affect the frequency of the trait in the rabbit population with two coat colors?

Brown-colored rabbits will increase in number due to lack of predation. Signup and view all the answers

What is biodiversity?

The term describes the variety of life on Earth. Signup and view all the answers

What defines a mutation?

Any change in the nucleotide sequence of the genome. Signup and view all the answers

Which type of speciation is present in apple maggots and hawthorn maggots?

Sympatric Signup and view all the answers

What is the likely significance of low genetic variation in a population?

The population cannot evolve in response to changing environments. Signup and view all the answers

What best defines a genetic disorder? (Select all that apply)

Abnormality of a chromosome Signup and view all the answers

What are the causes of biodiversity loss in a given area? (Select all that apply)

Invasive species Signup and view all the answers

What is habitat fragmentation?

The process in which a larger habitat gets divided into smaller habitats. Signup and view all the answers

What will reduce the population of the red-eyed tree frog?

Clearing of forest land. Signup and view all the answers

What option best defines invasive species?

An organism that is not native to a particular area. Signup and view all the answers

Which of these is an invasive species?

Kudzu Signup and view all the answers

How has the introduction of the zebra mussel impacted the ecosystem of the Great Lakes?

It increases algal blooms. Signup and view all the answers

What will be the effect of zebra mussels on the food web if they are introduced into Seneca Lake?

The number of nutrients in the lake will decrease. Signup and view all the answers

What does it mean to hybridize an organism?

The act of breeding individuals of two different species. Signup and view all the answers

What categorizes a species as endangered?

The species is likely to become extinct either in a specific area or worldwide. Signup and view all the answers

Which of these is an endangered species?

Cross River Gorilla Signup and view all the answers

What is the Endangered Species Act?

It is a program for the conservation of endangered species and their habitats. Signup and view all the answers

What is a gene drive?

It is a genetic engineering technology that guarantees the inheritance of a specific gene in the next generation. Signup and view all the answers

What are the potential uses of a gene drive? (Select all that apply)

Eliminating an invasive species Signup and view all the answers

How does a gene drive work?

It increases the chances of a gene being passed on to the next generation by creating an organism that is homozygous for a desired gene. Signup and view all the answers

How are genes inherited in organisms that are diploid?

A set of genes is passed from each parent organism to the resulting offspring. Signup and view all the answers

Study Notes

Natural Selection and Evolution

Natural selection is the process allowing living organisms to adapt and change over time.
For natural selection to occur, a key condition is the production of more offspring than can survive, leading to competition.
Genetic variation among individuals enhances the chances of survival and reproduction in changing environments.
Fitness of an organism encompasses both its ability to survive and reproduce successfully.

Population Dynamics

In a scenario with rabbits of varying coat colors, natural selection would favor brown rabbits, increasing their population due to reduced visibility to predators.

Biodiversity

Biodiversity is defined as the variety of life on Earth, crucial for ecosystem resilience.
A mutation is any alteration in the nucleotide sequence of an organism's genome, potentially affecting traits and functions.

Speciation

Sympatric speciation occurs when two species, such as apple maggots and hawthorn maggots, evolve from a common ancestor while living in the same area without overlapping food sources.

Genetic Variation and Evolution

Inbreeding reduces genetic variation, making populations less adaptable to environmental changes and hindering evolution.
Genetic disorders are caused by mutations in genes or abnormalities in chromosomes.

Threats to Biodiversity

Major causes of biodiversity loss include invasive species, climate change, and habitat fragmentation, which divides larger habitats into smaller, isolated areas.
Habitat fragmentation disrupts the ecosystem and threatens species survival.

Invasive Species

Invasive species, like kudzu and zebra mussels, are non-native organisms that can harm local ecosystems by outcompeting native species and disrupting food webs.
The introduction of zebra mussels increases algal blooms, negatively impacting aquatic ecosystems by depleting essential nutrients.

Conservation Status

A species is categorized as endangered when it faces a high risk of extinction in a specific area or globally, such as the Cross River gorilla with fewer than 2,500 mature individuals.

Endangered Species Act

The Endangered Species Act is a program aimed at conserving endangered species and their habitats, protecting biodiversity.

Genetic Engineering and Gene Drive

A gene drive is a technology that ensures a specific gene is inherited in future generations, potentially useful for eliminating invasive species or reducing pesticide use.
Gene drives function by creating homozygous organisms for desired traits, enhancing their inheritance likelihood.

Inheritance Patterns

In diploid organisms, genes are inherited from both parents, contributing to offspring genetic diversity and trait expression.

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Description

Test your understanding of natural selection and the conditions required for it to take place with these flashcards. This study tool covers key concepts in environmental science, specifically Unit 4. Get ready for your exam by reviewing these essential definitions and processes.