Genetics
MONTHLY PROJECT IDEAS
Gregor Mendel
DNA structure - Adenine, Guanine, Cytosine, Thymine
DNA mapping
The Human Genome
Genetic Code/DNA sequencing
Nature vs. Nuture
Family traits - heredity
Cloning
Mutations/Diseases
Evolution/Natural Selection
Chromosomes/proteins
Mitosis/Meiosis
Genetic Research - Plant modification, Medical,
STUDY GUIDE
Vocabulary:
Geneticist
stamen, pistil
pollination - self and cross
truebreeding and/or purebred
not truebreeding and/or hybrid
parent, filial
genes
dominant, recessive
sex cells - sperm/egg
incomplete dominance
punnett square
allele
homozygous, heterozygous
phenotype, genotype
chromosomes - x and y
mutations
mutagens
DNA, RNA - what, who, when
double helix
genetic code, start and stop codes
asexual and sexual reproduction
centromere
replication
heredity
gametes
mitosis and stages of
Essay:
Explain what Mendel did, what were his results and what were his hypothesies from each experiment
Three laws of genetics
Six basic principles of genetics
How to make a Punnett Square - for one and two traits
How are mutations both good and bad
Diagram, label, explain the stages of mitosis
Draw and label a DNA molecule
What do proteins do?
Given an example, explain incomplete dominance
Main functions of chromosomes
NOTES
Genetics - study of heredity
heredity - passing of traits from an organism to its offspring
Gregor Mendel - father of genetics
worked with pea plants
grow quickly and reproduce quickly
have many characteristics or traits (height, color of seeds, shape of seeds, etc)
stamens - male part of flower - produces pollen
pistils - female part of flower - pollination
self-pollination - pollination within same plant
cross-pollination - pollination between different plants
Mendel's work
began with 2 short plants
results were short offspring - called this truebreeding
believed always produced offspring with same traits as parents
next tried tall plants to see if they were truebreeding as well
results - some produced tall, some short
must be two kinds - truebreeding and not
next - took pollen from only truebreeding tall and dusted short truebreeding
named parents the P generation, first offspring filial or f1 generation
results - all plants in F1 were tall - mendel was amazed!
could not explain this result
next - allow f1 to self-pollinate, expecting f2 to be all tall
results - 3 talls and 1 short
conclusions - f1 not truebred(purebred) tall, had to contain characters for both tall and short (hybrid)
called factors for traits genes - units of heredity
dominant - expressed trait
recessive - unexpressed trait
every organism has 2 forms of the gene for each trait
geneticist - scientist who studies genetics
Mendel's hypothesis - each pea plant had a pair of "factors" for each trait
each plant could contribute only one gene for each pair to next generation
offspring gets one from each parent
sex cells - sperm for male, egg female- unite form fertilized egg
Law of Segragation - one gene from each pair goes to each sex cell
each fertilized egg contains one gene for each trait from each parent
Law of independent assortment - each gene pair for a trait is inherited independently of the gene pairs for all other traits
Law of incomplete dominance - neither gene in a gene pair hides the other
traits carried by the 2 genes appear to be blended
Basic principles of genetics
traits are passed from one generation to the next
traits are controlled by genes
organisms inherit genes in pairs - one from each parent
some genes are dominant, some recessive
when both inherited, dominant hides recessive
some are neither dominant or recessive
Punnett square - used to visually demonstrate genetic crosses- probable results
Phenotype - physical genetics
Genotype - genetic make-up
Chromosomes - rod shaped structures found in nucleus
Genes located on chromosomes
Chromosomes control all traits of organism
main function of genes to produce proteins - control production of specific proteins
proteins determine size, shape and other physical traits
chromosomes found in pairs
chromosomes X and Y shaped - XX female, XY male
Proteins - long molecule made of smaller molecules called amino acids (20 different amino acids)
build repair cells
most chemical reactions controlled by protein
hormones made of proteins
made in cytoplasm
dna controls how 20 amino acids put together
Meiosis - produces sex cells
Mutations - sudden change in a gene or chromosomes
takes place in body cell, if happens in sex cell passed onto offspring
two kinds - harmful - reduce chance of survival - helpful improve chance of survival
mutagens - cause mutations
DNA - deoxyribose nucleic acid
1953 by james watson and francis crick
dna stores genetic information and passes along from one generation to next
makes up genes
looks like twisted ladder
sides are sugar molecules and phosphates(hydrogen, phosphorus, oxygen)
steps formed by pairs called nitrogen bases
4 bases - adenine, guanine, cytosine, thymine
a-t and g-c always pair together
dna molecule makes a single chromosome - may have thousands of pairs
genetic code - order of nitrogen bases
possibilities limitless - explains diversity of life
3 letter code words
start code aug - stop codes uaa, uag, uga
RNA - ribose nucleic acid - carries genetic code from dna to ribosomes
mrna - is the messenger - trna reads code and begins putting together proteins
Cell division
2 ways
sexual formation of new cell through union of 2 cells(gametes) - sperm/egg
asexual production of offspring from one parent
genome - collective name for genetic information area
Prokaryotic cell division - diagrams
Mitosis - cell division in eukaryotic cells
interphase - primary growth, replication of genome(centromere and chromatid), organelle replication
prophase - early, middle, late -- chromatid divide
metaphase - chromatid line up at middle
anaphase - chromatid move towards poles
telophase chromosomes form from chromatid
cytokinesis - cell divides
Diagram hand outs