Characteristics of Living Things

It’s Alive!!!!

Objectives & Vocabulary Objectives •  To know if something

is living based on the six characteristics of living things

•  To understand different types of reproduction

•  To understand how organisms keep a balanced environment

Vocabulary •  Characteristic •  Biology (bio, ology) •  Cells •  Sexual Reproduction •  Asexual Reproduction •  Binary Fission (bi, fissure) •  Mitosis •  Meiosis •  Stimulus •  Homeostasis

What Does “Alive” Mean?

•  Biology = study of life •  Before we can study living things, we have to

be able to tell what is alive and what isn’t. •  Sometimes it’s easy, and sometimes it’s not

quite so simple. –  Rock: not living –  Fish: living –  Bacteria: living –  Virus: ______________

Qualifications for Living

To be alive, the object has to meet ALL of these qualifications:

1.  Made of 1 or more cells 2.  Obtains and uses energy 3.  Grows and develops 4.  Can reproduce 5.  Sense/respond to change 6.  Has DNA or RNA

Living Things Have Cells

•  Cells are the basic part of all living things. •  Different kinds of cells have different jobs •  Some organisms are single-celled

–  Bacteria •  Others are multi-cellular

–  Humans, plants, etc.

Living Things Use Energy •  Living things require energy in the form

of a chemical called ATP •  Energy is used to do digestion,

respiration, and movement •  Plants get ATP Energy from the Sun •  Most Animals get ATP Energy from food

Living Things Grow & Develop

•  All living things grow and change •  When cells divide to form new cells, the

organism becomes more complex •  Growing, changing, and becoming more

complex is called development

Living Things Reproduce

•  All living things reproduce to continue the species

•  Sexual Reproduction – offspring will have some characteristics of mother and some of father, therefore there’s greater variation among offspring –  Happens through fertilization and

mitosis •  Asexual Reproduction – offspring is an

exact copy of the first –  Happens through Binary Fission

Asexual Reproduction •  Binary Fission is the

process of asexual reproduction.

•  Bi = two •  Fission = split/divides •  One cell divides into two

equal parts that are identical.

•  Happens in single-celled organisms (bacteria)

Sexual Reproduction – Growth in Cells

•  Mitosis - cell division in non-sex cells

•  It results in two daughter cells from a single parent cell.

•  The daughter cells are identical to each other and to the original parent cell.

•  Similar to Binary Fission, but happens in multi-cellular organisms

Sexual Reproduction – Making Sex Cells

•  Meiosis – a specialized cell division that happens in sex cells

•  Sex cells are eggs and sperm

•  Two divisions occur, resulting in four daughter cells with half the number of chromosomes as the parent.

Living Things Sense/Respond to Change

•  Living things respond to a stimulus with change to maintain a balanced environment (homeostasis) Example: When it gets too hot, we sweat to cool down

•  When the stimulus is too much, it becomes stressed and could die or will have to adapt Example: If we don’t sweat, we die of over heating!

Living Things Have DNA/RNA

•  DNA/RNA - genetic material •  Located in the nucleus of

cells •  Job - Gives cells their identity •  That’s how kids inherit traits

from their parents - it’s held in their DNA!