Summary genetics

LESSON 2 GENETICS


 Metabolism/ homeostasis/respond to
environment

 reproduction

Basic parts and functions of a cell
 Cell membrane
 Nucleus
 cytoplasm




Cell membrane
What are Cells?
 Physical integrity of a cell
 Basic building blocks of life-define
 Plasma membrane, double layer of
structure and function of an organism
lipids and proteins
 Unit of reproduction
 Surrounds cells
 Microscopic and macroscopic
 Separates the cytoplasm fro its
Cell functions surrounding environment

 Structural and support unit of the body  Selectively permeable

 Contain body’s genetic material and can  Mechanical structure
make copies of it
 Cytoskeleton
 growth and development
 help define and maintain cell
 apical meristems, cell shape
multiplication, specialization of
 Extracellular matrix
tissues
 interaction of cell membrane
 Transport
with adjacent cells
 active and passive transport of
 Protection
nutrients, water
 Active transport
 Energy production

,LESSON 2 GENETICS


 movement of molecules against  Medium for chemical reaction- dissolve
concentration gradient and nutrients and waste product breakdown
requires energy
 Platform for other organelles operate
CM functions within the cell

 Bulk Transport: Exocytosis &  Home of the cytoskeleton
Endocytosis
 Cytosol
 Exocytosis
 cytoplasm part with no
 a cell moves the contents of organelles
secretory vesicles OUT of the
 Protoplasm
cell via the cell membrane.
 Endocytosis  made up of cytoplasm, nucleus
 is the opposite process by and other living cell
which the contents of secretory components
vesicles are moved INTO the  Hold components of the cell
cell via the cell membrane.  Protection of cell from damage
 Cell expansion and shape
 Markers & Signaling
 Growth
 surface protein markers embedded in  Replication
the cell membrane identify the cell,
Nucleus
enabling nearby cells to communicate
with each other.  Membrane bound organelle in most of
eukaryotic cells
 Cell membranes often include receptor
 Largest organelle(10% of cell volume)
sites for interaction with specific
 Houses the genome
biochemical
 Coordinates cell activities
 hormones, neurotransmitters
 Control of genetic information
and immune proteins.
 In this way the cell can  Control of protein and enzyme
recognize and process some synthesis
signals received from the
extracellular environment.  Control of cell division and cell growth

 Metabolic Activities  Storage of nucleic acids and ribosome

 Plasma membranes include as  Regulation of transcription of mRNA to
part of their structures certain protein
proteins and enzymes that are  Ribosome production
involved in some of the
metabolic processes of the cell. Chromosome Structure

Cytoplasm  E. Strasburger(1875)- discovered the
threadlike structures during cell division
 Gel like fluid inside the cell
 Has affinity for basic dyes

, LESSON 2 GENETICS


 Chroma- color Chromosome number

 Soma- body

 Term first used by Waldeyer (1888)

 Contribute to cell division and carry the
genes

 Located in the nucleus

 Made up of protein and DNA

 Passed on to generations

 Chromatin

 DNA-protein complex, relaxed Examples:
form of the chromosome • Man – 23 pairs of chromosomes
• Fruit fly- 4 pairs
 Chromosomes • Rice plant- 12 pairs
• Dog – 39 pairs
 condensed state of chromatin,

 Compactness Chromosome Functions in Human-somatic
 defining feature of any
chromosome, organize genetic
material during cell division and
fit inside the nucleus

Chromosome types and number

 Types

 Somatic or body chromosome
 Sex or gametic chromosomes
 Number

 Constant in a given species

 Somatic chrom. Number

 found in the body cells of
species
 2Z (diploid-two copies of each
chromosome)

 Gametic chrom. Number

 half of somatic chrom number,
n(haploid-found in gametes of a
species)