Population Genetics: Why do we have different skin colors?: Crash Course Biology #14

What is the primary focus of population genetics?

• Studying individual organisms in isolation.

• Examining similarities and differences within and among groups that make up populations.

• Analyzing the genetic makeup of single cells.

• Investigating the physical characteristics of different species.

In biology, what defines a population?

• Any group of organisms living in the same area.

• Organisms of different species that interact in a habitat.

• Organisms of the same species living in the same place at the same time that can feasibly make fertile babies with each other.

• A collection of organisms that share similar physical traits.

Why is high genetic diversity beneficial for a population?

• It makes individuals more identical to each other.

• It reduces the population's ability to reproduce.

• It makes the population more vulnerable to diseases.

• It increases the population's ability to adapt and survive environmental changes.

What percentage of human genes are the same across all individuals?

• 50%

• 75%

• 99.9%

• 100%

What are two important effects of ultraviolet (UV) light on the human body?

• It helps produce Vitamin C and destroys calcium.

• It helps produce Vitamin D and destroys folate.

• It helps produce Vitamin A and destroys melanin.

• It helps produce Vitamin B and destroys bone density.

How does skin color generally adapt to different levels of ultraviolet (UV) light around the world?

• Darker skin is common in areas with low UV light, while lighter skin is common in areas with high UV light.

• Darker skin is common in areas with high UV light, while lighter skin is common in areas with low UV light.

• Skin color is not affected by the amount of UV light in an area.

• All skin colors produce the same amount of melanin regardless of UV exposure.

What term describes gradients of change on a continuum, used to represent genetic diversity like skin color?

• Categories

• Races

• Clines

• Traits

What is the scientific understanding of "race" as discussed in the video?

• Race is a biological category defined by distinct genetic markers.

• Race is a social construct, an idea created and agreed upon by society.

• Race is determined by a single gene that reliably distinguishes different groups.

• Race is primarily based on hair texture and eye color, which have clear biological boundaries.