Genetics (MR. Maher Nayef) PDF

 Genetics (MR. Maher Nayef) Genetics:- is known a branch of Biology that deals with inherited variations of an organism or a group of organisms,, as well as how the expression of genes responsible for those variations.. *The first person who named this...

 Genetics (MR. Maher Nayef) Genetics:- is known a branch of Biology that deals with inherited variations of an organism or a group of organisms,, as well as how the expression of genes responsible for those variations.. *The first person who named this branch of science as Genetics was an English researcher called Bateson in 1906that helped in the progress of this science.. two scientists James Dewey Watson and Francis Crick in 1953 describe the molecular structure of DNA These scientific researchers showed the way to solve the genetic code.. * In 1986 the idea of using DNA in applied fields has started due to the DNA have a number of characteristics,, including:- 1- DNA has ability to be transported from one organism to another by some transporters such as viruses and plasmids.. 2- It has ability to modulate the recipient cell functions.. 3- It has ability to replicate inside a cell naturally and also outside,, through the use of Polymerase Chain Reaction ((PCR)).. - In seventies they were able to hybrid DNA of different types? A: :-- In order to find very effective drugs,, at the same time they succeed in discovering the genes that cause most rare genetical diseases caused by a single gene.. Mendelian genetics:- Explain \The result of Mendel research remained under wraps for a period of 34 years from the date of publishing? A: : Because the scholars were preoccupied with the theory of Darwin in organic evolution. Q\ What are the properties of living organisms used in genetics 1 -Short life cycle.. 2 -High number of offspring 3 -Having the possibility to get variations and genetic mutations when organ- - isms are exposed to unsuitable environmental conditions such as radiation and chemicals.. 4- Ability to control fertilization or mating of the organism.. 5 -Easy to breed and maintenance..  Genetics (MR. Maher Nayef) 6 -Ability to produce new structures as a result of sexual reproduction or delivery ( (Transduction) ) by viruses. Explain \ The success of Mendel in his experiments despite of failure of other scientists?(2007) A: 1- Chosen best model in design and analysis of genetic experiment it is Pisum sativum which has genetic variation, , ability to grow easily and susceptibility to hybridization artificially.. 2- Mendel limited his research on one pair of traits or less in each experiment.. 3- Keeping accurate records and relied upon in the statistical analysis of his experiences. Explain: - Chosen of Pisum sativum plant by Mendel?(1\2005) (1\2003 ) (2\2000) A: : Because it has genetic variation, , ability to grow easily and susceptibility to hybridization Artificially Q\ the chromosome number of the following :- Mosquito 6 – Fruit Fly 8 - Bee ( Male 16 – Female 32 ) – Cat 38 – House Mouse 40 – Human 46 Pea 14 – Corn 20 – Bean 22 – Rice 24 – Grain 28 - Sunflower 34 Some genetic terminologies and symbols 1. Allele Different form of mutation of a gene.. One of the different forms of a gene that can exist at a single locus.. 2..Genes Is a sequence of DNA that has a specific function, , for example, , turning the genetic code to a protein or controlling the expression of character and can prove itself throughcontrast alleles.. 3. Gene Expression It is the process of using DNA information by cells in the manufacturing of a particular protein.. 4. Genotype ( (G) ) it reflects the composition or structure of the genetic of individual.. It expresses the genetic codes together in a particular individual.. 5. Phenotype or phenotypic category ( (P) ): : It refers to the properties or observed signs of the organism which is genetically controlled.. monohybrid cross (2013\2, 2019\3)a genetic hybridization between two individuals and includes a pair of opposing traits such as aa X A.. Thus it reveals how transmission versions of these qualities through the generations take place.  Genetics (MR. Maher Nayef) Reciprocal cross :- Crossing gets between two individuals, , one carrying a dominant pure trait and the other carries the recessive pure trait or vice versa * If the results in both cases are similar then the gene for that falls on the somatic chromosome.. * If the results were different at the opposite type, , it means that the trait gene located on sex chromosome or in the cytoplasm of organelles. Q\ Explain: scientist used reciprocal cross? Or what is the purpose of reciprocal cross? (2016\2(2019\1) A\ for the purpose of making sure that certain trait has the gene located on either the somatic chromosome or sexual chromosomes, , or located in cytoplasmic organelles such as mitochondria. Mendel first law, , which is called " "Law of Segregation" " (1\2014)(1\2005)(1\91) The paired genetic factors in an individual split from each other when the gametes are formed.. After it formed in pairs again during fertilization when the genetic individuals are created.. Hybrid trait (1\2007)(2\2002) It is a trait that is represented by a pair of non- -identical ( (homologous) ) genetic factors carried by an individual resulting from the mating of two pure parents who differ in a certain trait. Test cross( 2006 – 2011 -2014 ) The aim of this crossing is to identify the genotype of the individual which holds dominant unknown purity.. It crossed with another recessive individual for that trait.. If all the members were carrying the dominant trait, , then this member must be pure in that trait.. If either 50%of the members were dominant and 5 50 0% % recessive, , that means that the individual hybrid in trait. Q\ Using Test Cross or what is the purpose of test cross? (2015\3) (2016\ ‫)خ‬ A: to identify the genotype of the individual that holds dominant unknown purity. Back cross :- ( 2007)(2\2014 )(2014 \‫ ) ن‬It is a cross between hybrid members of the first generation with a parent or with an individual similar to one of them.  Genetics (MR. Maher Nayef) Dihybrid cross :- it is a crossing between hybrid members of the first generation with one of the parents or with an individual similar to one of them The Law of independent assortment and also known as Mendel second law (2\2016) ( 5002\‫)خ‬ (00\2):- The isolated pairs of genetic factors are distributed independently from each other during gametogenesis Chromosome: This is the installation of composite linear shape of the DNA molecule, , Ribonucleic acid ( (RNA) ) and protein, , which contains the coded genetic information sequence and can be viewed through the process of cell division. The gene :- is a part of DNA chromosome that controls at least in specific genetic trait Probability: is the likelihood of the occurrence of a specific event by estimation or calculations.. It can be expressed as the number of decimal, , percentage or number of fractional and determined by the following equation Post Mendel genetics :- 1- Properties that Deviate Mendelian ratio 3:1  Genetics (MR. Maher Nayef) a. Incomplete dominance:-Phenotype of the hybrid individual is different than the parents.. This takes a compromise between the two types.. This is the average between the two phenotypes for the two pure opposite traits as a result of mixed cross for these two traits.. This situation is different from thecase of full purity of the traits studied by Mendel. Q\ what is the type of genetic that study the pink color in the flowers of Snapdragon plant? A: Incomplete dominance Q\ What is the genetic phenotype of the following organisms? Are there pure individuals? And why? Snapdragon plant pink flowers (2000\1) A:The genotype is R𝑹∕, and there are no pure individuals of it, , because it is an incomplete dominance trait or because pink flowers are a hybrid trait and represent an intermediate state between the state of the two pure parents ( (red flowers and white flowers) ) b. Codominance (91\2, 92):- This is the case in which expression of two alleles seen together in the phenotype of the hybrid individual.. Neither one of the traits is dominant or recessive. Q\ What is the genetic phenotype of the following organisms? Are there pure individuals? And why? Dust color cattle? A\ C R CW , and there are no pure individuals of it, , because it is a Codominance trait  Genetics (MR. Maher Nayef) Lethal alleles (1\2006 )(1\2005 )(2\2002)(1\96)( 1\94):- These alleles will cause the affected member to suffer if the member carries it.. This expression leads to death of an individual which inherit a pure dominant in some cases or recessive in Q\ what is the reason for Sickle-cell Anemia ?A: recessive mutant allele (H ) Q\ explain: Sickle-cell Anemia allele has many effects? Or what are the effects of Sickle-cell Anemia allele? A: affects the quality of hemoglobin Hb.. It becomes some kind of abnormal type ( (Hemoglobin S) ).. It also affects the shape of red blood cells they become scythe shape instead of the normal disc shape.. Explain \1- When multiplication a creeper chicken with a creeper rooster quarter the result was dead? A: because creeper chicken have the lethal allele ( (C) ) which is become lethal or killer when it found in a pure individual ( (CC) ) which result from multiplication a creeper chicken with a creeper rooster.. 2 - Death of a quarter of individuals resulting from internal mating of creeping chickens? (1\2002)? A: Because the two lethal alleles combine in the pure state ( (CC) ) because the parents are hybrids (Cc) Penetrance Gene: : (2014) This is the probability of an individual inherits allele and possess phenotypic trait which is related to allele.. For example recessive allele that causes cystic fibrosis with complete penetrance of 1 10 00 0% % of pure individuals ( (cc) ) has the disease.. As well as the dominant allele to acquire extra fingers ( (Polydactyl) ) in the hands or feet is incomplete penetrance.. This is because some individuals which inherit this allele have ten normal fingers, while others have more than ten.. The expressive: : ( 2013\2,2015\ ‫ت‬,2018 ‫ ) خ‬It means an allele could produce a heterogeneous range of phenotypic types.. An example of this is pure insect for the recessive gene for the mutation of eyeless which gives phenotype with various ranges between the existences of normal eye to partial loss in the eye size in one or both eyes. Q\ when rabbits fed on plants containing the yellow color, then this color will appear in their fat‫؟‬ (2000\1, 2007\1) A: because of the presence of a recessive gene ( (vy) ) rabbits carrying this gene suffer from a lack of enzymatic and thus become unable to demolish the yellow color which can be found in the carrots and in other plants so the color will appear in their fat. Q\ give one evidence of the genetic affect by environment factors? (2000\2)  Genetics (MR. Maher Nayef) A: human body weight and the color of fat in Rabbits Q\ who is responsible for yellow fat in rabbits? (2015\3, 2019\2) A: recessive gene ( (yy) ) and food with yellow color which found in the carrots Gene interaction :- This is producing new phenotype by interaction alleles peculiar to different genes.. Multiple alleles:- This is the availability of alternatives or various alleles for the same gene, , as a result ofmutation happened the molecule of ( (DNA) ) genetic material.. This cause variety in the Phenotype. Some examples of Multiple alleles:- 1- ABO System in Human 2- RH antigens 3- About the blood group Rh Explain \ The availability of alternatives or various alleles for the same gene? ( 1\2019 ,1\2016 ,2\2006 ,2\98 ,1\96) A: as a result of mutation happened the molecule of ( (DNA) ) genetic material.. This cause variety in the phenotype Example \1- ABO System in Human Q\ Explain the following :- 1-It is possible that type O blood when transferring it to carriers of other groups?( 2\2005 ,2\99) A: This is because there is no antigen on the surface of type O red blood cells for antibodies to interact with in plasma. 2- It is not possible to give blood from group A to a person whose blood type is (B) advice versa?(2/2009) A: Because the antigens on the surface of the donor’s red blood cells are ( (A) ) and the antibodies present in the recipient’ s blood serum are ( (A) ) and thus this causes clumping or clotting the donor' 's red blood cells in the recipient' 's blood vessels 3 Blood clotting occurs when blood is transfused from one person to another with a different blood group?( 2011\2)  Genetics (MR. Maher Nayef) A: Due to clotting or aggregation and adhesion of the donor' 's red blood cells inside therecipient' 's blood vessels as a result of a reaction between antigens and antibodies between the donor' 's blood and the recipient' 's blood. Rh antigens * It was dis covered by two scientist called Landsteiner and Weiner in1940. Q\ Explain: It was given a great deal of attention to the Rh antigens? A: that because of their direct emergence of a case of anemia for some newborn babies Q\ the blood groups ABO and the Rh have to be tested on the verge of marriage?( 2010\2) A; This is to exclude the emergence of Erythroblastosis Fetalis disease in their children and to take the necessary precautions.. Q\ explain: the mothers will be given Anti-Rh immediately after birth antimatter's (Anti-Rb) Ri+? A; These kinds of antibodies destroy cells of RH+ + type, , which has passed to the mother' 's blood circulation.. So she is unable to produce antibodies for the recipient.. Q\ explain: In the city of Basrah, it has been found that 93%of the sample studied possessed Rh+ and 7% of all was Rh? A: It has found that the negative type is less in the Eastern societies perhaps because of the election against negative alleles.. Q\ In which case is the fetus’s life in danger? Explaining the reason when the fetus isRh+ 1- When a man is Rh- and a woman is Rh+ 2- When the man is Rh+ and the woman is Rh- 2/2015 A: : 1- There is no risk because the woman is Rh+ + and she is the one that forms the antibodies if she is Rh negative.. 2-There is a risk because the woman is Rh and the fetus is Rh.. When blood is transferred from the fetus to the mother through a placenta that is defective due to a genetic reason, , antibodies will be present to it.. In the second pregnancy, , the concentration of antibodies will rise within the mother’s body.. When the antibodies pass through the placenta to the fetus, , they begin to break down the fetus’ ’ s red blood cells.. Causing him anemia locally called ( (Abu Saffar) Q\Explain: If the mother is Rh- and the father is Rh+ , the mother is injected immediately after birth with an anti-Rh substance?  Genetics (MR. Maher Nayef) A: Because this substance helps the mother get rid of any blood that had leaked to her from the fetus, , and thus antibodies do not form and the risk to the child disappears in the second pregnancy.. Q\ If a person needs blood type (A-) 1/2015 1 - What type can be save him by writing their genotypes? Mention the antibody in the serum for each possible species? A: Possible type : Type ( (A- -) ) and ( (O- -) ).. Genotypes: 1- Ttype A- - rhrh IA i , , rhrh IA IA 2- Type O- - ii rhrh The antibodies in the serum of type A antibody is b.. The antibodies in the serum of type ( (O) ) are a, , b. Q\ What are the alleles responsible for inheriting fur color in rabbits? 2004\2 A: Allele C is responsible for the gray ( (wild) ) fur color.. The allele is responsible for the silvery fur color.. The allele is responsible for the color of Himalayan fur.. The allele is responsible for the color of the albino fur. Mutation :- is sudden change in succession of nitrogen bases of a gene or of a molecule of DNA; ; this change is associated with appearance of new phenotype and genotype on the base of the quality of cells. *There are mutations happens in the germ cells which is represented by the * gametes of organism, , the mutations of reproductive cells don' 't effect the organism itself but it may transfers to his children. * There are mutations happens in the somatic cells of the organism * then effects it, , for example some types of skin cancer and blood cancer in human, , this type of mutation doesn’t inherits.  Genetics (MR. Maher Nayef) Harmful mutations as in the case of wings reduction in Drosophila melanogaster, , shorten legs in sheep and many of diseases and syndromes in human Lethal mutation can be lethal which leads to the death of embryo before birth.. Useful mutation which leads to increase the animal and plant production and improve the quality. First Chromosomal mutations:- Chromosomal mutations divide into two main types: 1. Mutations because of changes in the number of chromosomes: A. Aneuploidy, , in this case there is one missing chromosome or one extra chromosome.. B. Polyploidy, , this is an increase in complete chromosome group so the organism has triple chromosome ( (3 3n) ). 2. Mutations because of changes in structure of chromosomes: A) Change in the number of genes that includes deletion which means losing part of chromosome.. B) Change in the order of genes that includes inversion which is part of a certain chromosome breaks and reverses, , then unites again with the chromosome itself and the transition which part of a certain chromosome breaks and unite with another not identical chromosome. Second genetic mutation includes two type :- A- point mutations:- It is the product mutation from deleting or adding or exchange one nucleotide with another one which belongs to one genetic location ( (Locus) ).. 1- Deleting mutation: : In this one nucleotide will be missing from a certain gene.. This mutation may leads todangerous affects in the function of protein. Codon( 1\2006)(2\2005 ):- three nitrogenous bases or three nucleotides in a DNA or RNA molecule that relate to or encode information for one amino acid. 2- Insertion Mutation: : This is to insert one nucleotide into a certain gene which may leads to displace mutation too 3 - Substitution Mutation: : One nucleotide replaces with another one ( (B) ).. If this Substitution happens in a certain codon, , the amino- -acid changes B-Duplicate Mutation :-This includes affect more than one pair of nitrogen base for the gene, , this happens through repetition of copying part of gene. 1- the average of mutation for the one gene in drosophila melanogaster is nearly ( - 2- The total average of mutation in these insects is around (% - 1%).  Genetics (MR. Maher Nayef) Explain :- the scientist have found recently ant mutagens material for some mutations? Because of the problems which mutation causes, Anti- -mutagens :- 1) Bio anti- -mutagens: These are stopping factors, , it has role within multiplying the DNA or other factors which has role within the operation of repairing the damage. 2) Des- -mutagens: : This is like finding anti- -material which works directly on mutagens such asanti- - oxidation or finding Blocking Agents. Define Mutagens (2009\1) :-are chemical or physical factors that help increase the average of mutation occurrence when an organism exposure to it like radiation with high energy such as ultra violet rays and ionic radiation like x-rays or some chemicals like nitric acid, metallic salts and Explain\ Down syndrome is a chromosomal mutation? A: because the person with down syndrome have additional copies of chromosome ( 21) results in 47 chromosomes instead of 46. Q\ blank: Genetic mutation includes two types Point mutations and Duplicate Mutation ( (2015) ) Q\what is reason of shorten legs in sheep? (2009, 99, 2007) A: mutations Q\ what are the difficulties which facing the researches in Human genetics field? (‫\ت‬5002)(2\2010)) I. The small size of the human families don' 't allow all the possibilities to appear, , so it is difficult to make sure of the purity of the parents traits, , so the big size families are more desirable in the genetic studies, , but the number of the biggest human families is much less than the right number to put genetic ratios statistically testable.. 2. The age of one generation since the birth until it reaches the age of adolescence are many years, so following the traits in the next generation takes long time.. 3. The marriage in human is regarded as private issue which is impossible to control it or direct it according to the marriages which are controlled by experiments.. 4. Many of human traits are not controlled by Mendel' 's genetics but they are controlled by non- - Mendel' 's genetics such as an accompanying dominant, , in- - complete validity, interference the genetic action, , multi genes with an accumulated affect which is impossible to study the effect of each one individually. 5. Large number of chromosomes in human comparing to the other organisms Pedigree:- IT is a diagram shows the producer of a certain trait' 's genetic throughout many generations.. The squares in this diagram refers to males, , the circles refers to females. The square or the dark circle means the presence of the trait or the case with the person in a certain generation and  Genetics (MR. Maher Nayef) vice versa for the light color symbol.. The horizontal line which connects the male to the female refers to the marriage.. The vertical line refers to the children which have been arranged from left to right according to the order of the birth disrespect of the sex. The Roman numbers refers to concession of generations. The standards of dominant traits which are the responsible gene for each trait is located on body chromosome:- 1-The trait transfers in male and female by equal frequency.. 2 - The consecutive generations are infected.. 3 - Stopping the transfer after the generation which there isn' 't any affected one.. The standards of the recessive traits are the following: 1- The male and female are frequently affected at the same level, , and the affected memberscan transfer the gene except in the case of death before the age of adolescence.. 2 - The traits can disappear for number of generations.. 3-The parents of the affected person are heterozygote or carrier of disease. Human Chromosomes The chromosomes which are not directly related by determination the sex in human are called Autosomes and they are 22 pairs and the remaining pair as we know it represents the sex chromosome ( (one pair represents the sex) ). Chromosomes of human may differentiate according to centromeres location to the following types: a-Metacentric Chromosome; ; centromere is located at the center and the locus of chromosome at the same size b-Sub metacentric Chromosomes; ; centromere is closed to one of the poles and louses are in different sizes.. C-Acrocentric Chromosome; ; centromere more closed to one of the poles and look as "I" during cell division.. d-Telocentric Chromosome; ; centromere located at one of the poles.. On the bases of the length of chromosome and centromere' 'slocation, , the chromosomes of human can be ordered in 7 7groups of Autosomes from A - - G, , and one pair of sexual chromosome either (XY) ) or ( (XX) ).. On that base so the 23 pairs Chromosome A B C D E F G X Group 1-3 4-5 6-12 13-15 16-18 19-20 21-22 XX and XY  Genetics (MR. Maher Nayef) Q\Who is the Diagnosing the genetic diseases :- A- -Method of Amniocentesis.. B- -Method of examine of Chorionic villi which are located in the lining of uterus Q\ what are the Reducing the symptoms of some genetic diseases 1. Diet: : This described for some genetic metabolism diseases such as phenyl Ketonuria.. 2. Physiotherapy: : This described for cystic fibrosis patients, , so the patients have many sessions which hitting on the back and the chest will be used to get the sticky mucus from the lungs.. 3. Using certain injections for some diseases such as insulin injection which are used to treat urine diabetes and the injection of blood clotting protein to treat Hemophilia. Important questions Diagnosing the genetic diseases Reducing the symptoms of some genetic diseases 4. Using some surgical operations for the embryo ( (limited cases) ) to repair some genetic abnormalities.. 5. Treatment by the genes, , exchanging the gene which suffers problems in function, , that' 's by reducing the symptoms of disease which the original gene is responsible for it Genetic counseling :-Many people with a family history of a genetic disease also undergo genetic counseling, , the process of informing a person or couple about their genetic makeup.. Genetic counseling is a form of medical guidance that informs individuals about problems that might affect their offspring.. By studying the data from genetic screening tests and the family' 's pedigree, , a genetic counselor can predict the likelihood that a couple will produce an affected child.. For diseases that have both genetic and environmental influences, After a half century of discover 1-Know the range of affecting some members of the family by one of the genetic diseases.. 2 -Know what leads to ( (relative marriage) ) possible genetic diseases.. 3 3.. Know the causes of irregular sexual formation or late sexual maturity.. 4- Give advises in case of frequent miscarriages.. 5- In case of identifying the father.. 6 -In case of finding out the danger of medicines and radiation. Human genome:- Ait’s an genetic order of about 3, 3 billion pairs of nitrogen' 's bases in human chromosomes. Genetics (MR. Maher Nayef)  Genetics (MR. Maher Nayef) Molecule base for genetic (( Detection of DNA)) Scientists depended on three studies definite that DNA is the genetic material: : 1- Krevet experiments on bacteria, , so he explained that there is genetic factor which did the Transformation; ; he could transfer the ability of killing between types of bacteria cells.. 2 -The experiments of Avery showed that DNA and not the protein are responsible of Transformation in bacteria.. 3-The experiments of Hershey and Chase, , these two scientists in ( (1 19 95 52 2m) ) had a test to know if ( (the DNA or the protein) ) is the genetic material which the virus transfer it or bacteriophages. Can explain this experiment in three steps: A-Radiation was used to distinguish DNA from the protein in virus, , so radiated phosphor (P) was used for the DNA and the radiated sulphur ( (S³³) ) was used for the protein.. After that thetwo scientists left the virus which contains the radiated phosphor and the one which contains the radiated sulphur individually to affect the bacteria ( (Escherichia coli) ).. B- The layers of virus were removed from the cells by certain processer.. C- The viruses were separated from bacteria by using Centrifuge.. The result was all viruses' ' DNA a little bit of protein interred to bacteria.. On that base it was concluded that the part of virus which affected bacteria cell and multiply- - ing its DNA not its protein. The Structure of DNA Each Nucleotide consists of three simplest molecules connected with each otherdirectly it is from out to inside as follows: 1. Pentose sugar which called Deoxyribose, , the molecule form is ( (C6 6 H1 12 2 O6 6) ).. 2. Phosphate group: : This consists of an atom of phosphate ( (P) ) is connected by four atoms of oxygen ( (O) ). Types of Nitrogenous Bases :- A- -Pyrimidine: : includes the following normal bases 1 -Thymine ( (T) ) it is available in DNA only.. 2 -Cytosine ( (C) ) it is available in both nucleic acids.. 3 -Uracil ( (U) ) it is available in RNA only..  Genetics (MR. Maher Nayef) B-Purines: : includes two buses 1 -Adenine ( (A) ) it is available in DNA and RNA.. 2 -Guanine ( (G) ) it is available in DNA and RNA.. * In (1949 ) the scientist Chargaff ingratiate that the percentage for Adenine equals the percentage for Thymine, also the percentage for Guanine equals the percentage for Cytosine Complementary base pairs are important in DNA' 's structure and function for two reasons:- 1 -Because the bonds between the base pairs helps to hold the two DNA chains.. 2 -Because of complementary nature for the DNA helps to explain how it is replication before the cell division. RNA TYPES We will mention three types of RNA and all of them are made in nucleus of the cell and transferred to cytoplasm, , so it has role in protein synthesis and they are: 1 -Messenger ( (mRNA) ); ; it is a molecule transfer genetic message from DNA which is available in the nucleus to the ribosomes which is available in the cytoplasm in the cells of eukaryotes. 2 -Ribosomal ( (RNA) ): : it is part of the structure of ribosome; ; it shares with protein in its 3 -Transfer ( (tRNA) ) it transfers amino acids to the ribosome for protein synthesis.. It was noticed the amino acids connect to this acid ( (tRNA) ) before transfer it to the ribosome. Q\ what is the chemical structure of ribosomes? A: protein and rRNA Q\ what is the origin of chromosomes (5102\‫) ت‬ A: from chromatin network Q\ define the following - Nucleotides 2 20 01 19 9\ \1 1: : it is the building block of nucleic acids DNA and RNA and it consists of three simplest molecules connected with each other directly are Pentose sugar, , Phosphate and Nitrogenous Base.. - Nucleosome: : it is units that form the chromatin material that forms chromatin reticulum, , consist of four molecules of histone each one presents in dual case  Genetics (MR. Maher Nayef) Q\ blank: Pyrimidine includes nitrogen bases Thymine ( (T) ) , ,Cytosine ( (C) ) and Uracil ( (U) ) Q\ what is the feature of adenine? A: don’ ’t contain oxygen Q\ give an example of nitrogen base lack of oxygen? A: Adenine Q\ what is the importance of the DNA? 2008\1 A: The substance that makes up the genes and the sequences of nitrogen bases in it determine the features of the organisms.. Q\ where is the location of hydrogen bonds?( 2010\1 )Q\ what is the location and function of hydrogen bond?( 2015\2) A: location: :- - between nitrogen bases in the DNA molecules Function: :- - connect the nitrogen bases to each other’ s and the bonds between the base pair that help hold the two chains of DNA Q\ what is the importance of mRNA? 2010\2, 2016\2 A: transfer genetic message from DNA which is available in the nucleus to the ribosomes which is available in the cytoplasm in the cells of eukaryotes.. Q\ explain: The linkage of the bases between two chains is not random? A: because adenine in one of the chains always connects with thymine in the other chain by two hydrogen bonds, , and cytosine in one of the connects with guanine in the other chain by three hydrogen bonds.. Define uracil ( 2005\2):- it is a nitrogen base found in the RNA and it one of the pyrimidine (monocyclic) contains nitrogen in addition to carbon, , hydrogen and oxygen.. Q\ blanks: - two scientist Watson and Crick put the idea for DNA structure  Genetics (MR. Maher Nayef) Genetic Code :- points out the succession of nitrogen' 's bases in mRNA ( (Messenger RNA) ) so three nearby nucleotides represents Codons and deter- - mine an amino acid or points to the beginning of Initiation or to stop the translation.. DNA Polymerase ( 99\ 2): - The enzymes that add completing nucleotides which are inside nucleus to each one of the original chains and off course the covalent bonds form between nearby new nucleotides. Q\ what is The main property for the genetic material DNA? A: is the ability to replication in the beginning of each cell division Explain \DNA replication called Semi-Conservative Replication. A: Because of produces two separated molecules in each chain; ; one of them is original and the other one new by DNA polymerase which mostly repairs the mistake Explain \ The replication is carefully done, so one mutation can happen for each one billion of added bases pairs? A: the reason is the presence of DNA polymerase enzymes which mostly repairs the mistake.. Q\ what is the function of the following 1- Helicase enzymes: : separate the DNA' 's chain for replication 2- DNA Ligase: : holes get connected in between the chain which is forming recently 3- DNA Polymerase : a-adds completing nucleotides to each one of the original chains b- - Ends the replication and then separate from it and produces two separated molecules in each chain c- - Repairs the mistake  Genetics (MR. Maher Nayef) DNA translation: regarded as a step in protein synthesis and it happens in the ribosomes and codons have been used in mRNA molecule for the determination of amino acids succession in polypeptides chain and include three main steps 1- initiation stage 2- Elongation stage 3- Termination stage Q\ explain\ In prokaryotic can start the translation before the transcription ends? A: that because prokaryotic don’ ’t have nucleic membrane separates its nucleic acid (DNA) from ribosomes which is present in the cytoplasm. Define Polysome : it’s the translation that can many ribosomes may translate the same copy of mRNA happened in prokaryotic. Q\ Translation is regarded as a step in protein synthesis( 2016 \ ‫( خ‬ Genetic Engineering It is the techniques of changing the genetic structure for the living cells or the individuals through removing some genes or hybrid a new molecule of DNA or altering it to enable the cell or the organism to gain the desirable traits.. The following are main needs for the technique of genetic engineering: 1- A method of cutting down the molecules of DNA which carries the required gene to transfer by one of the restriction enzymes.. 2-A suitable carrier which carries the new piece of DNA.. This take place through its unite with DNA carrier with the help of DNA Ligase enzyme, , so the hybrid piece ( (rDNA) ) marked by its ability to replication inside the recipient cell.. 3-A method to enter the hybrid piece of ( (rDNA) ) including the carrier piece for the gene that is going to be transferred to the recipient cell.. 4-A method of finding the recipient cell and its generations which carry the desirable hybrid piece and separate it from the rest of colonies members who doesn’t' 't contain that piece Restriction enzymes :-These are bacterial proteins which are used to know the certain succession of nitrogen base for the DNA molecule and it' 's cutting down.. Also these enzymes break the internal phosphate bonds for the DNA.. Phages:- are simple structured viruses which affect the bacteria or remains inactive.. It contains single or double DNA strips or it may contain single RNA.. An example for this is the phagelambda..  Genetics (MR. Maher Nayef) Plasmid :- It is a small circular from the additional DNA molecule which is present in many bacteria. Q\ what are the characteristics of plasmid? (2015\1) 1- It carries a small number of genes which are responsible for some traits like Bacterial resistance for the antibiotic.. 2- It replicates itself independently from the bacterial chromosome.. 3- It can be transferred from one bacterium to another and for many organisms such as yeast, , fungus and insects Genetic practices Determine the succession of complete nucleotides ( (Human genome) ) to know the genetic map.. Genetic practices :- what are the Genetic practices 1 -is the molecule of DNA or RNA which is mono- -chain and it is marked by radioactive phosphor and complement for the DNA desirable succession and it is required to find it, , as a result of connection between the probe with complementary DNA piece will form a double radioactive spiral. 2 - it’s used in justice field.. 3- it’s used in the field of following the human immigration and some other organisms from its environments especially the ones threatened by extinction.. 4 -Producing human insulin hormone, , protein interferon material, , clotting factors number ( 8) blood protein and different vaccinations.. 5 -Transferring the trait of nitrogen fixation to other types of bacteria.. Q\ what is the function of the following:- 1- Restriction enzymes: These are bacterial proteins which are used to know the certain succession of nitrogen bases for the DNA molecule and it' 's cutting down.. Also these enzymes break the internal phosphate bonds for the DNA.. 2- Probe is the molecule of DNA or RNA which is mono- -chain and it is marked by radioactive phosphor and complement for the DNA desirable succession and it is required to find it as a result of connection between the probe with complementary DNA piece will form a double radioactive spiral..