名词解释

1. Dominant:
   1. dominant allele:the allele that is expressed when two different alleles or two dominant alleles are present
   2. symbol: Uppercase letters
   3. Dominant trait/character: to cross two homozygous parents with a pair of relative character, the trait that is presented in F1
   4. essence:it depends on the nature of the protein that is, or is not made

2. Pyrimidine:
   1. Definition: it is a kind of heterocyclic compound
   2. Components: Thymine ,Cytosine and Uracil
   3. Characteristics: their bases have single carbon rings

3. Base-pairing rule:
   1. Definition:thymine(T) always pair with adenine(A), and cytosine(C) always pair with guanine(G).
   2. Principle: the sizes and the ability of the bases to form hydrogen bonds with each other
   3. Paring method: A-T-two hydrogen bond, C-G-three hydrogen bond
   4. Founder: Chargaff’s rules (all four base are found in each organism, and the proportion of the four bases are different)

4. Recessive:
   1. Recessive allele: that expressed only when two copies are present.
   2. Symbol: lowercase letters
   3. Recessive trait/character: to cross two homozygous parents with a pair of relative character, the trait that is not presented in F1
   4. essence:it depends on the nature of the protein that is , or is not made

5. Gene:
   1. Definition: it’s a piece of DNA that provides a set of instructions to a cell to make a certain protein
   2. Function: instructions to a cell to make a certain protein
   3. Locus: a specific position on a pair of the homologous chromosomes

6. mRNA:
   1. Definition:is an intermediate message that is translate to form a protein
   2. Production: in control dogma, transcription of DNA.
   3. Characteristics: Single strand+ A\U\C\G+
   4. Function: as a temporary copy of DNA that is used and then destroyed

7. Genotype:
   1. Definition: refers to the genetic make up of a specific set of genes.
   2. Characteristics:includes both of the genes that code for one traits, even if one of these genes is masked.
   3. Classification:homozygous/heterozygous
   4. Function:determines phenotype

8. DNA polymerase
   1. Definition: is a group of enzyme that bond the new nucleotides together
   2. Function: can form bond between nucleotides during replication
   3. Position: moves along a DNA strand
   4. Characteristics: it needs a primer; from 5’ to 3’ direction

9. Bacteriophage:
   1. Definition: is a type of virus that can infect bacteria
   2. Components: protein coat + DNA
   3. Ways to infect: adhere to the bacteria . Inject the DNA, copy DNA and protein,

10. Primer:
    1. Definition: short, single strand DNA or RNA that serves as an attachment point for DNA polymerase
    2. Production: another enzyme( primase )starts making them after DNA strands are separated
    3. Function: exposed nucleotide bases on a single strand of DNA form hydrogen bonds with complementary bases of primer

11. Semiconservative replication:
    1. Definition:describes the process of DNA replication in which one strand of each copy of a DNA molecule is new,and the other is a strand of the original DNA
    2. Purpose: assures that every cell has a complete set of identical genetic information
    3. Time: during S(synthesis) stage of the cell cycle

12. Phenotype:
    1. Definition: the physical characteristics, or traits of an individual organism make up it.
    2. Expression in different individuals:Recessive/Dominant character
    3. Characteristic: determined by genotype; the phenotype is for visible traits, the hidden genes doesn’t matter to this phenotype.

13. Segregation of characters:
    1. Definition:The offspring emerges an new trait that haven’t shown among its parents.
    2. Application: the new appearing character must be recessive trait
    3. Characteristic: parents must be heterozygous
    4. Foundation: law of segregation

14. Homozygous:
    1. Definition:it describes two same alleles at a specific locus.
    2. Characteristic: the genes in two locus of a pair of homologous chromosomes are the same
    3. Relationship with allele: only have recessive/dominant allele

15. Heterozygous
    1. Definition:it describes two different alleles at a specific locus.
    2. Characteristic: the genes in two locus of a pair of homologous chromosomes are different
    3. Relationship with allele: Have both Recessive/ Dominant allele

16. Multiplication rule:
    1. Definition: multiply the probability of each event
    2. Function:the calculate the probability that two independent events will happen together
    3. Application: to calculate how many kinds of germ cell that can be produced; to calculate the probability of the offspring that will be heterozygous/homozygous

17. Addition rule
    1. Definition: plus the probability of each event
    2. Function:the calculate the probability that one of the independent events will happen.
    3. Application: to calculate the probability of the offspring that will be heterozygous/ homozygous