Biological membranes consist of
lipids, proteins, and carbohydrates.
The fluid mosaic model describes a
phospholipid bilayer in which
membrane proteins move laterally
within the membrane.
Peripheral proteins attach to the surfa
Class 10 Genes
1. Recap of DNA
Made of: nucleotides
Nucleotide sequence = A,G,C,T (links through hydrogen bonds)
Looks like: twisted ladder
DNA contains genetic information
Particular sequence of DNA encodes for a specific protein: gene
Class 7 Mitosis
1. Cell Division
Unicellular organisms uses cell division
1. Mainly for reproduction
Multicellular organisms uses cell division:
1. For reproduction
2. For tissue growth
3. For reparation of tissue
Two types of cell division
Class 6 Cells
How did the First Cells Originate?
Lipid bilayer formed by fatty acids
Small molecules that allows sugars and nucleotides to pass through
Presence of nucleotides in protocells results to new polynucleotide chains
2. Cell Siz
Class 13 Patterns of Inheritance
Genetic diseases can be caused by defects on genes located on regular chromosomes
1. Autosomal diseases
Genetic diseases can be cause by defects on genes located on sex chromosomes (almost
always the X)
Class 8 Meiosis
Nuclear division for the formation of haploid reproductive cells (egg & sperms: spores) in
Produces cells that are genetically different from the parents, and also from each other
which causes genetically differen
Class 11 Mendelian Genetics
1. Important Terms
P Generation = First set of parents crossed in which their genotype is the basis of
predicting the genotype of their offspring
F1 Generation = First filial generation of offspring distinctly different paren
The Cell Cycle and
Cell division is necessary for reproduction,
growth, and repair/regeneration of an
Unicellular organisms use cell division
primarily for reproduction.
In multicellular organisms, cell division
Life and Chemistry:
Large Molecules #2
Carbohydrates: Sugars and Sugar Polymers
Carbohydrates are carbon molecules with hydrogen
groups and hydroxyl groups
They act as energy storage and transport molecules.
They also serve as carbon skeletons
Inheritance, Genes, and
The Foundations of Genetics
The foundation for the science of genetics was
laid in 1866, when Gregor Mendel used varieties
of peas to conduct experiments on inheritance,
but was generally ignored until the early
Biology and the Tree of Life
What is Life?
Life can be defined as an organized genetic unit
capable of metabolism, reproduction, and evolution.
What is Life?
An organisms metabolism is its total chemical
activity and consists of thousands of indiv
Cells #2: The Working Units
The endomembrane system includes the
plasma membrane, nuclear envelope,
endoplasmic reticulum, Golgi apparatus,
Tiny, membrane-bound vesicles shuttle
substances between the various
Early Atmosphere &
Water and the Origin of Lifes Chemistry
The earliest chemical signatures of life on Earth
are about 4 billion years old.
The presence of water, possibly brought by
comets striking the Earth, was critical in making
Evidence and Mechanisms of
Charles Darwins Theory of Evolution
Darwin observed that slight variations among
individuals can significantly affect:
the chance that a given individual will
the number of offspring it will produ
Cells #1: The Working Units
Cell theory was the first unifying theory of
biology. It states:
Cells are the fundamental units of life.
All organisms are composed of cells.
All cells come from preexisting cells.
Implications of cell theory:
Life and Chemistry:
Large Molecules #1
Theories of the Origin of Life
Living things are composed of the same elements as
the inanimate universe.
But, the arrangement of these elements in biological
systems is unique.
There are two theories for the
Species and Their Formation
What Are Species?
In 1940 Ernst Mayr proposed the
biological species concept: Species are
groups of actually or potentially
interbreeding natural populations which
are reproductively isolated from other such