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