Cells The Basic Unit s of Living Things

Organization of Life Cells: Tissues: cells working together Organs: Organ System: start out small; two or more tissues working together plant leaf Ø ~stomach Ø ~ basic unit of living things organs working together in groups

We all began as… A single cell Now we are MULTICELLULAR. We are made up of about 100 trillion cells

Cells: All cells are surrounded by a cell membrane All cells have DNA. Chromosomes are organized structures of DNA It holds the parts of the cell together.

Unicellular ~a single cell that is living on its own

Cytoplasm ~the jelly-like fluid that surrounds everything within the cell ?

Steps of Mitosis 1. 2. 3. 4. 5. DNA makes a copy of itself Nuclear membrane breaks down Chromosomes line up in middle of cell Chromosomes pulled to opposite ends Nuclear membrane reforms and two new cells are formed

vacuole mitochondria (holds water) (make energy) cell wall (strengthen/support ) chloroplast (photosynthesis occurs)

Locate: cell membrane, nucleus, and cytoplasm Cell membrane nucleus cytoplasm

10 Question: If a parent cell has 10 chromosomes before dividing. How many chromosomes will each new cell have after the parent cell divides? Ø Ø A. 10 B. 5

Why use stains when looking at cells? Because many slides are clear and would not be visible.

Is this cell eukaryotic or prokaryotic? How do you know? Eukaryotic – it has a nucleus

Is this cell likely to be a plant or animal cell? Animal Cell 1. Has NO cell wall 2. Has NO chloroplasts 3. Has NO large vacuole