What are the building blocks of life? All living things are made of cells. A cell is the smallest unit of a living thing. Cells are too small to be seen without a microscope. All plant and animal cells have a CELL MEMBRANE, cytoplasm, and a nucleus. The nucleus of a cell controls the cell’s activity. Cells that look similar can have different jobs. To study the small details of a cell you would use a microscope.

How are living things grouped? Scientists use a classification system to study, compare, and identify living things. An organism may be classified according to the number of cells and cell parts it has, where it lives, and how it obtains food. Scientists organize living things into six major categories called kingdoms. The 1 st part of an organism’s name is the genus and the 2 nd part is the species.

Ancient Bacteria Ancient bacteria have only one cell and no separate nucleus. These organisms may live on land or in water, and many of them live in extremely hot or salty habitats. They make their own food.

True Bacteria True bacteria are also one-celled organisms that have no separate nucleus. They live on land or in water. Some of these bacteria must get food. Others make their own food.

Protists Most protists are one- celled. They have a nucleus and other cell parts. They live in water and moist environments. Many must get their food, but some make their own. Algae, amebas, and paramecia are protists

Fungi Most fungi are many- celled organisms. Each cell has a nucleus and other cell parts. Fungi live on land and need to get food from other living or nonliving things. Mushrooms, yeasts, and molds are fungi.

Plants Plants have tissues and organs that are made of many cells. Each cell has a nucleus and cell wall. Most plants live on land, but some live in water. They use the Sun’s energy to make their own food.

Animals Animals are many-celled organisms with tissues, organs, and systems. They live in land or water environments. Animals do not make their own food. They get energy by eating plants or other animals.

Vascular and Nonvascular Plants Vascular plants have tube like structures that transport water and nutrients within the plant. Vascular plants can grow tall. Examples are grass, ferns, dandelions, celery, and trees. Nonvascular plants grow low to the ground and can pass water and nutrients only from one cell to the next. Nonvascular plants DO NOT have true roots, stems, or leaves. Liverworts, hornworts, and moss are all examples of nonvascular plants.

How Plants Make New Plants Flowering plants like fruit trees, cactus, and wheat reproduce by producing new seeds. Cone-bearing plants like pine trees reproduce by producing new seeds. They make seeds but DO NOT have flowers. Ferns and mosses DO NOT make seeds. They reproduce by producing spores.

Vertebrates and Invertebrates Animals that have a backbone are vertebrates. Fish, amphibians, reptiles, birds, and mammals are all vertebrates. Animals that DO NOT have a backbone are invertebrates. Most of the world’s animals are invertebrates. Arthropods(spiders), sponges (Spongebob), sea stars(star fish), worms, and mollusks(snail) are all invertebrates.

How do animals adapt? Adaptations are physical features or behaviors that help organisms survive and reproduce in an environment. Markings on a butterfly that scare away predators is an example of an adaptation. Birds knowing how to migrate is a behavior they are born knowing. Bears knowing how to fish is a behavior they learn from their parents.

Essay question Compare and contrast the life cycle of a Burmese python and a garden snail. Both mate and lay eggs. The snail leaves, but the python stays until the eggs hatch. When the eggs hatch, the young of both species are on their own. The python lives much longer than the snail.