High School Biology

Cell Theory

Cell Theory

• The cell is the smallest living unit in all organisms

• All living things are made of cells

• All cells come from other pre-existing cells

Nucleus

Membrane bound organelle, contains the cells DNA

Rough ER

contains ribosomes; proteins are synthesized

Smooth ER

Phospholipids, fats, and sterols are synthesized

Ribosomes

location of protein synthesis; is mostly made of mRNA

Golgi Complex/body/apparatus

modifies, processes and sorts protein products from the ER

Mitochondria

POWER HOUSE OF THE CELL!! Main role is the production of ATP energy through cellular respiration

Plasma/cell membrane

Lipid bi-layer, surrounds the cell and is responsible for transport in/out of the cell

Cytoplasm

cell shape, material transport like genetic material and products for cellular respiration, and storage

Lysosome

Cell organelle filled with enzymes needed to break down certain materials in the cell

Cell Wall

Surrounds plant, fungal, and bacterial cells, provides strength and rigidity to the cell

Central Vacuole

stores water, dissolved substances, and wastes: also maintains correct water pressure within the cell

Chloroplast

carry out the process of photosynthesis

Flagella

Whip like tail used to move; found in some bacterial cells, sperm cells, some protists

Chromosomes

a threadlike structure of nucleic acids and protein found in the nucleus of most living cells, carrying genetic information in the form of genes

Heredity

passing traits down from one generation to the next

Gregor Mendel

Considered the father of genetics

Genes

code for a specific trait

Alleles

variations of a trait (2 alleles per trait)

Homozygous

same allele (BB or bb)

Heterozygous

different alleles (Bb)

Dominant

One variant of a gene on a chromosome masking or overriding the effect of a different variant of the same gene

Recessive

Is expressed only if both the alleles are homozygous and NOT dominant

Genotype

Genetic description (Bb or bb)

Phenotype

physical features (Brown eyes/blue eyes)

Mutations

alterations that occur within a DNA sequence. They can cause diseases and conditions, but are also key in the development of new traits or even species!

Natural Mutations

mutations can occur during cell mitosis or meiosis when DNA is being copied

Environmental Mutations

mutations can be caused by environmental factors such as chemicals or from ionizing radiation from the sun

Substitution

when one base is changed for another

Insertion

when an extra base is added to the copy

Deletion

when a base is removed from the copy