Sci 7 Q4 W8

A student observed that the early embryos of all of these five organisms look similar to each other. Which statement is the most likely explanation for this observation?

• They have all originated in the same habitat.

• They are all classified in the same genus.

• They have all developed from a single parent.

• They have all evolved from a common ancestor.

Analyze the photographs of the four animals in their embryonic stages. What pattern of similarity helps explain their embryological development?

• A. Each animal develops similar parts in the same order.

• B. Each animal begins similarly to its adult form and then grows larger.

• C. Each animal begins development with similar structures and then develops its characteristic parts.

• D. Each animal develops in a unique way, with random similarities.

Scientists have discovered a fossil skeleton of a whale-like creature that lived in the early Eocene epoch. The skeleton shows an organism with large fore and hind limbs with distinct toes. Fossil skeletons of closely related species from later periods show organisms lacking hind limbs.

• A. Ancestors of whales had fewer bones than modern whales.

• B. Whales and their ancestors have always been ocean dwellers.

• C. Whales and their ancestors have always been the largest living animals.

• D. Ancestors of whales may once have been able to walk.

An adult pig and an adult chicken look very different from one another. How do their embryological developments suggest similarities between them?

• Both embryos develop external structures like wings and hooves early in development, which later differentiate into species-specific features.

• Both embryos show similar developmental stages, such as the presence of pharyngeal pouches and tails, indicating common ancestry.

• Pig embryos develop feathers before losing them, while chicken embryos briefly develop mammalian-like hair follicles.

• Their embryological developments are entirely different, showing no shared traits at any stage.

Which type of structure is similar across multiple species and shows an evolutionary relationship?

• adaptive

• analogous

• homologous

• metamorphic

The feathers of male goldfinches become brightly colored each spring. Which best describes why the color of the feathers changes each year?

• a genetic mutation

• a learned behavior

• a behavioral adaptation

• a physical adaptation

Which of these adaptations is least important for human survival?

• having thumbs

• eye color

• walking upright

• developing language

In the early 1800s, light-colored moths could be found resting on light-colored trees in England. At the beginning of the Industrial Revolution, the trees began to turn dark because of black soot from factories. By 1898, most of the moths found in England were dark in color. Which most likely enabled the dark-colored moths to survive and reproduce more than the light-colored moths?

• Dark-colored moths were covered by pollution and were no longer threatened by predators.

• Dark-colored moths were able to convert the soot to a chemical that was toxic to the predators.

• Dark-colored moths were faster than light-colored moths and therefore able to escape predators.

• Dark-colored moths were able to blend into the dark background and were not easily detected by predators.

A mild environment begins to experience a gradual decrease in temperature resulting in much colder winters than previous years. Which variation would most likely be selected for in an organism that lives in this environment?

• one that reduces fat and builds lean muscle

• one that produces longer, more dense coats of fur

• one that results in larger ears allowing for more efficient heat loss

• one that requires an organism to nest in trees instead of on the ground

The cheetah population around the world has decreased because of poaching and loss of habitat. The surviving population is found to have similar alleles. Which factor is endangering the species’ survival the most?

• harmful genetic mutations

• shrinking of the gene pool

• decrease in competition

• increase in adaptations