1. Genetics
Chapter

2. Character Traits (p.350) Humans are different in many ways.
Character traits are the physical, psychological, and physiological attributes that vary from individual to individual.

3. Chromosomes Most eukaryotic cells contain a nucleus.
The nucleus contains the genetic information.
The main component of the nucleus is chromatin.
Chromatin is a mass of DNA and proteins.
Humans have 46 chromosomes.

4. Chromosomes are visible under a microscope.
They are formed when chromatin contracts.
Chromosomes are the carriers of the gene or unit of heredity.

5. DNA p.353 (Deoxyribonucleic Acid)
GENES – a DNA segment that contains info for making proteins which CODE FOR A SPECIFIC TRAIT
DNA is made up of repeating molecules called NUCLEOTIDES

6. DNA Nucleotide O O=P-O N CH2 O C1 C4 C3 C2 Phosphate Group
Nitrogenous base
(A, G, C, or T)
CH2 O C1 C4 C3 C2 5
Sugar
(deoxyribose)

7. Watson & Crick proposed…
DNA had specific pairing between the nitrogen bases:
ADENINE – THYMINE
CYTOSINE - GUANINE
DNA is made of 2 long strands of nucleotides arranged in a specific way called the “Complementary Rule”

8. DNA Double Helix “Rungs of ladder” Nitrogenous Base (A,T,G or C)
“Legs of ladder”
Phosphate &
Sugar Backbone

9. PROTEINS (p.355)
Proteins are responsible for our physical appearance, they also make sure that our body can function.
The human body has more than proteins each with a specific role.
Genes provide the information to make proteins.

10. Example of Protein Tasks
Support: Elastin is a protein that make our skin firm yet elastic.
Transport of substances: Hemoglobin is a protein that carries O2 in the blood.
Immunity: Antibodies are proteins that protect us from disease.

11. Control and Message Relay: Hormones areproteins that help make the body develop properly.
Catalysis: Enzymes are proteins that speed up biochemical reactions in the body.

12. Protein Structure p.356
Proteins are made up of one or more chains of small units called amino acids.
There are 20 different amino acids.
Some chains are very long, containing 600 amino acids.
Usually proteins have an average of amino acids.

13. Protein Synthesis
Our cells have the ability to make the proteins they need.
The genes that have the instructions to make the proteins are in the cell nucleus.
The actual process is carried out by ribosomes, which are outside the nucleus.

14. Since DNA cannot leave the nucleus, a messenger is needed to bring the information from the DNA to the ribosome.
This messanger is RNA-ribonucleic acid.
RNA is a single strand.
In RNA, Thymine(T) is replaced with Uracil (U).
The sugar in DNA is deoxyribose but in RNA it is ribose.

15. Two types of RNA
Messanger RNA (mRNA) is the messenger for carrying the instructions from the gene to the ribosome.
Transfer RNA (tRNA) transfers the amino acid in the cell’s cytoplasm to the ribosomes in order to make proteins.

16. DNA RNA  protein: and overview of information flow in a cell
Making a protein from the instructions in the DNA is a two step process:
Transcription and
Translation
Read p

17. Principals of Heredity p.358
There are similarities between members of the same family.
Heredity is the transmission of parent’s character traits to their offspring.

18. Gregor Mendel “father of genetics”

19. Please copy
Mendel studied the inheritance of one trait. (for example plant's height, color of  flowers or shape of seeds).
Crossbreeding: Is the exchange of gametes between 2 different individuals during sexual reproduction.

20. Steps of Mendel's Experiment- crossbreeding p.360-361

21. Alleles p.362
When Mendel was doing his research he did know about chromosomes or genes.
He did know that there must be several possible alternatives for each “gene”. These different forms are called alleles.
An allele is a possible form of a gene.

22. Homozygotes and Heterozygotes p.362
When both alleles for a certain character trait are identical, this is a homozygote. (e.g. RR or rr)
When both alleles are different for a given trait, this is a heteozygote. (e.g. Rr)

23. Dominant and Recessive Alleles p.363
Mendel discovered that some alleles are dominant and others recessive.
The allele that is expressed is the dominant allele.

24. Genotype and Phenotype p.364
A genotype is the person’s genetic inheritance.
A phenotype is the way a genotype expresses itself.
Each allele is represented by a letter.
A dominant allele uses a capital letter and a recessive allele a lower case letter.

25. Cloning p.369
There are 2 natural methods of reproduction: sexual and asexual.
Until now, we have the transmission of heredity through sexual reproduction.
Asexual reproduction involves only one parent.

26. Cloning is the reproduction of an individual, part of that individual or one of its genes in order to obtain an exact copy.
There are 2 types of cloning: natural and artificial.

27. When cloning happens in nature without any human intervention it is called natural cloning. (p.369)
There are 3 forms of natural cloning:
Budding
Layering
Propagation by cutting
Natural cloning produces genetically identical individuals through asexual reproduction.

28. Artificial Plant Cloning p.370
Have you or your parents or grandparents ever taken a cutting from a plant, put it in water until roots grow and then transfer it to a pot. This is an example of artificial plant cloning.
Farmers often use the in vitro method to clone crops.
Read p.371 carefully.

29. Animal Cloning p.372 To clone animals artificially the steps are:
1) remove a cell containing the DNA of the animal to be cloned.
2) take an ovum from another animal and remove its nucleus
3) combine the DNA cell and the DNA-less ovum
4) implant the new cell in the uterus of a surrogate mother
5) A clone of the target animal will develop in the surrogate mother.

31. Who did they clone?
In 1997, they successfully cloned the first animal- a lamb named Dolly.
Why do they want to clone animals?
They do this to study genetic disorders and disease susceptibility.
It is done strictly for medical research.

32. Human Cloning p.373 There are 2 forms of human cloning:
REPRODUCTIVE cloning: Using cloning techniques to obtain a new individual genetically identical to the one being cloned.
Therapeutic Cloning: Using cloning techniques to obtain tissues or organs genetically identical to those of the person in need of a transplant.