Life Science
Life Processes Standard (2.4)
The student will investigate and understand that plants and animals undergo a series of orderly changes as they mature and grow. Key concepts include
a) animal life cycles; and
b) plant life cycles.
a) animal life cycles; and
b) plant life cycles.
Understanding the Standard (background information)
- Throughout their lives, plants and animals undergo a series of orderly and identifiable changes.
- Changes in organisms over time occur in cycles and differ among the various plants and animals.
- Some animals, such as mealworms, pill bugs, frogs, and butterflies go through distinct stages as they mature to adults. Other animals, such as crickets, praying mantises, gray squirrels, and white-tailed deer, resemble their parents from birth to maturity and do not have distinct stages.
- White-tailed deer are the largest herbivores in Virginia. They are found in all areas of Virginia including forests, open fields, mountain tops, coastal islands, and in cities and towns. Their diet consists of grasses, leaves, nuts, fruits, and fungi. Virginia’s white-tailed deer have few predators. Fawns may be taken by bobcat. Other mortality factors include hunting, motor vehicles, poaching, and trains.
- Newborn white-tailed deer are called fawns. They become yearlings at 14 to 18 months of age. As adults, males are called bucks and females are called does. White-tailed deer are tan or reddish brown in the summer and grayish brown in the winter. The underside and throat are white, and the tail is brown above and white below.
- A white-tailed deer’s lifespan averages eight years.
- Of the more than 200,000 kinds of vascular plants in the world today over 95 percent flower at some time in their lives. The best-known flowers are bright and colorful but others, like those of grasses, are small and inconspicuous.
- The basic stages in the life cycle of flowering plants include: seeds,germination of the seed, growth of the stem and roots, growth of leaves, growth of flowers, fertilization (pollination) of the flowers, production of fruit/new seeds, and death.
Living Systems Standard (2.5)
The student will investigate and understand that living things are part of a system. Key concepts include
a) living organisms are interdependent with their living and nonliving surroundings;
b) an animal’s habitat includes adequate food, water, shelter or cover, and space;
c) habitats change over time due to many influences; and
d) fossils provide information about living systems that were on Earth years ago.
a) living organisms are interdependent with their living and nonliving surroundings;
b) an animal’s habitat includes adequate food, water, shelter or cover, and space;
c) habitats change over time due to many influences; and
d) fossils provide information about living systems that were on Earth years ago.
Understanding the Standard (background information)
- Living organisms are dependent on other living organisms and their nonliving surroundings for survival.
- All of the interactions between and among living organisms and their nonliving surroundings are referred to as a system.
- Shelter may be living (coral, tree) or nonliving (caves, houses).
- The habitat of an animal includes adequate food, water, shelter or cover, and space. If any of the basic elements of an animal’s habitat are absent, the animal’s survival is threatened. The animal may adapt or leave the area.
- The habitats of living organisms, such as forests, grasslands, rivers, and streams, change due to many human or natural influences (e.g., forest fires, hurricanes, and droughts). Habitats change from season to season.
- Fossils found provide scientists with information about plants and animals that lived on Earth many years ago. (e.g., The rise and fall of sea level is recorded in the richly fossiliferous rocks of Virginia’s coastal plain. An abundance of marine fossils – fossil clams, snails, sand dollars, shark’s teeth, and whalebones – can be found in Virginia’s coastal plains.)
- Virginia’s state fossil, Chesapecten jeffersonius, is a large extinct species of scallop that dates to approximately 4.5 million years ago. It was the first fossil ever described in North America and is named after Thomas Jefferson, one of our founding fathers, and an amateur paleontologist.