Adaptations, Variations And Natural Selection And Selective Breeding

1. Over time, a certain species of hummingbird has developed traits including a small body, brightly colored feathers, a long, narrow beak, and the ability to drop its body temperature while it sleeps. Which of these characteristics is most likely a trait that developed in response to reach available food sources inside small knot holes in trees?

Small size

Bright coloration

Long, narrow beak

Body temperature decrease

The beaks adapted the long narrow beaks needed to fit inside the knot holes to get to food sources.

Explanation

The beaks adapted the long narrow beaks needed to fit inside the knot holes to get to food sources.

2. Which internal structures of animals are specifically adapted to use contraction to cause movement?

Blood cells

Muscles

Bones

Skin

Muscles are inside organisms and allow them to move.

Explanation

Muscles are inside organisms and allow them to move.

3. Galapagos finches are birds that live on islands off the coast of South America. The finches on the various islands are very different from each other. As a result of the different food resources on the islands, which of the following structures of the Galapagos finches experienced the greatest change through natural selection?

Head size

Eye shape

Feather color

Beak shape

The Galapagos finches have different beaks sizes and shapes depending on what food they eat.

Explanation

The Galapagos finches have different beaks sizes and shapes depending on what food they eat.

4. A farmer wants to increase the amount of food produced by corn crops. If the farmer selectively breeds the plants, for which trait should the farmer select?

Taller stems

Deeper roots

More cobs on the plant

Resistance to pesticides

The cob is the part of the corn plant that is picked and eaten. More cobs on the plant equals more food.

Explanation

The cob is the part of the corn plant that is picked and eaten. More cobs on the plant equals more food.

5. What environmental condition is likely to increase the frequency (more) of brightly colored and highly scented flowers in a species of plants over many generations?

Increase in shade

Heavy precipitation

Higher soil nutrient levels

Insects that pollinate plants

Insects are required to move pollen (male plant sperm) from plant to plant to seed the plants so more plants can grow.

Explanation

Insects are required to move pollen (male plant sperm) from plant to plant to seed the plants so more plants can grow.

6. In a population of desert plants, the timing of their blooming varies greatly. Some bloom early in the morning, others at mid-day, and others after dark. What environmental factor might have caused it to be an advantage to those plants that have adapted to blooming after dark.?

There is an increase in the population of insects that pollinate at night

There is a decrease in the strength of solar radiation

There is an increase in herbivores that look for food at night

There is a decrease in water for root absorption

The plants that have adapted to blooming after dark may have an advantage because there is an increase in the population of insects that pollinate at night. These plants are able to attract and rely on these nocturnal pollinators for successful reproduction. By blooming at night, they increase their chances of being pollinated and producing offspring, compared to plants that bloom during the day when there may be fewer or no pollinators available. This adaptation allows them to maximize their reproductive success in their environment.

Explanation

The plants that have adapted to blooming after dark may have an advantage because there is an increase in the population of insects that pollinate at night. These plants are able to attract and rely on these nocturnal pollinators for successful reproduction. By blooming at night, they increase their chances of being pollinated and producing offspring, compared to plants that bloom during the day when there may be fewer or no pollinators available. This adaptation allows them to maximize their reproductive success in their environment.

7. A table of the physical traits of chickens is provided. A breeder records the average data on three generations of a chicken population that has been bred. For which trait is the breeder most likely selectively breeding?

Heavier body weight

Longer beaks

More white feathers

More tail feathers

Weight is the ONLY trait in the table that increases from Generation 1, to Generation 5, to Generation 10.

Explanation

Weight is the ONLY trait in the table that increases from Generation 1, to Generation 5, to Generation 10.