What is hybridization?

• The mating or genetic mixing of two distinct species

• The process of natural selection

• The adaptation of species to new environments

• The extinction of a species

According to the Biological Species Concept, what defines a species?

• Organisms that can mate and produce fertile offspring

• Organisms that share similar physical traits

• Organisms that live in the same habitat

• Organisms that have the same number of chromosomes

What is a backcrossed hybrid?

• An offspring resulting from a hybrid mating with one of its parent species

• A hybrid that cannot reproduce

• A hybrid with equal genetic material from both parent species

• A hybrid that is sterile

Why are mules generally infertile?

• They have an odd number of chromosomes

• They are a result of human intervention

• They are not adapted to their environment

• They have weak genetic material

What is introgression?

• The incorporation of genetic material from one species into another through repeated backcrossing

• The extinction of a species due to hybridization

• The process of natural selection favoring hybrids

• The adaptation of hybrids to new environments

Which concept uses DNA sequencing to define species?

• Genetic Species Concept

• Biological Species Concept

• Morphological Species Concept

• Ecological Species Concept

Explain generally how a species is defined, and how hybrids may be an exception to that rule.

Why don't ligers (or tigons) exist in the wild?

• Ligers and tigons are only found in zoos due to their size.
• Ligers and tigons are too weak to survive in the wild.
• Ligers and tigons are protected species and cannot roam freely, because they have been over hunted.

• Ligers don't exist in the wild because lions and tigers do not share the same habitat; generally they live on different continents.

Recall and build: Changes to our DNA happen all the time. What determines whether a genetic mutation is passed down or not?

What are three reasons that hybrid species may be beneficial to agriculture?

• Increased yield potential due to larger fruit sizes or number of kernals (like an ear of corn)

• (Often) sterile offspring don't allow for the crop to regenerate on its own.

• Reduced genetic diversity.
• Greater adaptability to environmental changes, as you can cross an existing plant with something more heat or water resistant.

• Enhanced disease resistance, because of a larger genetic diversity