GENETICS

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We are made up of….

Unit 3

Unit title: GENETICS

Area of interaction:Human Ingenuity

MYP unit question: Should we be concerned

about the human influence on our future genetics?

What is GENETICS?• The study of genes and the inheritance of traits.

• The study of variation and inheritance

DNA, RNA and proteins

The basic behind genetics

• DNA is a nucleic acid, made of long chains of nucleotides

DNA and RNA are polymers of nucleotides

Figure 10.2A

Nucleotide

Phosphate group

Nitrogenous base

Sugar

Polynucleotide Sugar-phosphate backbone

DNA nucleotide

Phosphategroup

Nitrogenous base(A, G, C, or T)

Thymine (T)

Sugar(deoxyribose)

• DNA has four kinds of bases, A, T, C, and G

Figure 10.2B

Pyrimidines

Thymine (T) Cytosine (C)

Purines

Adenine (A) Guanine (G)

The following diagram shows a short stretch of DNA. What bases are indicated by labels Y and Z?

Y ZA. thymine adenineB. thymine guanineC. uracil guanineD. uracil adenine

• RNA is also a nucleic acid– different sugar

– U instead of T

– Single strand, usually

Figure 10.2C, D

Phosphategroup

Nitrogenous base(A, G, C, or U)

Uracil (U)

Sugar(ribose)

• James Watson and Francis Crick worked out the three-dimensional structure of DNA, based on work by Rosalind Franklin

DNA is a double-stranded helix

Figure 10.3A, B

A definition….• Protein: A large molecule composed of one or

more chains of amino acids in a specific order. Molecules that carry many life-related processes.

blogs.discovermagazine.comhttp://www.uscnk.com/directory/P-Protein%28P%29-0256.htm

www.license.umn.edu

– The DNA is transcribed into RNA, which is translated into the protein (The sequence of amino acids in a protein is defined by the sequence of a gene, which is encoded in the genetic code)

Figure 10.6A

DNA

RNA

Protein

TRANSCRIPTION

TRANSLATION

• The information constituting an organism’s genotype is carried in its sequence of bases

U C A G

U

C

A

G

GACU

GACU

GACU

GACU

UUUUUCUUAUUG

CUUCUCCUACUG

AUUAUCAUAAUG

GUUGUCGUAGUG

phe

leu

leu

ile

met (start)

val

UCUUCCUCAUCG

CCUCCCCCACCG

ACUACCACAACG

GCUGCCGCAGCG

ser

pro

thr

ala

UAUUACUAAUAG

CAUCACCAACAG

AAUAAC

AAGAAA

GAUGACGAAGAG

tyr

stopstop

his

gln

asn

lys

asp

glu

UGUUGCUGAUGG

CGUCGCCGACGG

AGUAGCAGAAGG

GGUGGCGGAGGG

cys

stoptrp

arg

ser

arg

gly

First Base T

hird Base

Second Base

Virtually all organisms share the same genetic code “unity of life”