Cell theory

Cell division, sexual vs. Asexual reproduction,

Cell meaning

Cell meaning

A cell is the simplest form of life that can live and function independently. Molecules and atoms do not show the 7 functions that living organisms do. Every living organism I made of one or more cells. The cell is the basic unit of structure and function. All cells arise from pre-existing cells.

Cell division meaning

process by which a cell divides into 2 new cells

Reasons cells divide

• Living things grow by producing more cells, NOT because each cell increases in size

• Repair damaged tissue (nerve cells cannot be repaired)

• If cells get too big, it cannot get enough nutrients into the cell and wastes out of the cell

Differentiation meaning

the process by which cells, tissue, and organs acquire specialized features, especially during embryonic development.

Totipotent Cell meaning

Potential to be any type of cell. (blank slate)

Mitosis stages

Interphase

Prophase

Metaphase

Anaphase

Telophase

Interphase (mitosis)

step 1: when the cell becomes bigger

Prophase (mitosis)

Step 2: the cell makes protein. DNA doubles

Metaphase (mitosis)

Step 3: DNA (chromosomes) line up in the equator (center)

Anaphase (mitosis)

step 4: spindle fibers pull & split chromosomes

Telophase (mitosis)

step 5: cytoplasm divides (Cytokinesis)

Asexual reproduction factors:

• Requires only 1 parent

• Offspring have 100% the same chromosomes as the parent

• Clones

• Most unicellular organisms reproduce this way

• Mitosis

Sexual reproduction factors

• Requires 2 parents

• Not identical to the parents

• The offspring has chromosomes from both parents

• Most multicellular organisms reproduce this way

• Meiosis

All cells have:

• Ribosomes

• Cytoplasm

• DNA (chromosomes)

• Cytoskeleton

• Cell membrane

Ribosomes

They make protein for use by the organism

Cytoplasm

It is a fluid material within the cell

DNA (chromosomes)

(Deoxyribonucleic acid)

Genetic material

Cytoskeleton

Internal framework of the cell

Cell membrane

Outer boundary, some things can cross the cell membrane

Living system characteristics

MRSGREN

Movement

Respiration

Senses

Growth

Reproduction

Excretion (Co2, urine, sweat)

Nutrition

Examples of unicellular organisms

Bacteria, fungi, yeast

The organizational hierarchy of organisms

Cells → tissue → organs → organ systems → orgnisms

Tissue

A group of cells in the body that perform the same function. i.e. bone marrow

Organs

Part of an organism with a specific function, made up of tissue. i.e. skin, heart, brain

Organ system

An organ system is composed of a group of organs that work together to accomplish one or multiple functions. i.e. digestive system, cardiovascular system, pulmonary system…

Organism (multicellular)

An organism is composed of multiple organs systems that work together to function as an individual entity.

Cellular membrane

The cellular membrane is the boundary that controls what enters or leaves the cell. It separates the inside from the outside. What goes in (O2, glucose), what comes out (CO2, waste). All cells have a cell membrane. It surrounds the cytoplasm.