名词解释
- Dominant:
- dominant allele:the allele that is expressed when two different alleles or two dominant alleles are present
- symbol: Uppercase letters
- Dominant trait/character: to cross two homozygous parents with a pair of relative character, the trait that is presented in F1
- essence:it depends on the nature of the protein that is, or is not made
- Pyrimidine:
- Definition: it is a kind of heterocyclic compound
- Components: Thymine ,Cytosine and Uracil
- Characteristics: their bases have single carbon rings
- Base-pairing rule:
- Definition:thymine(T) always pair with adenine(A), and cytosine(C) always pair with guanine(G).
- Principle: the sizes and the ability of the bases to form hydrogen bonds with each other
- Paring method: A-T-two hydrogen bond, C-G-three hydrogen bond
- Founder: Chargaff’s rules (all four base are found in each organism, and the proportion of the four bases are different)
- Recessive:
- Recessive allele: that expressed only when two copies are present.
- Symbol: lowercase letters
- Recessive trait/character: to cross two homozygous parents with a pair of relative character, the trait that is not presented in F1
- essence:it depends on the nature of the protein that is , or is not made
- Gene:
- Definition: it’s a piece of DNA that provides a set of instructions to a cell to make a certain protein
- Function: instructions to a cell to make a certain protein
- Locus: a specific position on a pair of the homologous chromosomes
- mRNA:
- Definition:is an intermediate message that is translate to form a protein
- Production: in control dogma, transcription of DNA.
- Characteristics: Single strand+ A\U\C\G+
- Function: as a temporary copy of DNA that is used and then destroyed
- Genotype:
- Definition: refers to the genetic make up of a specific set of genes.
- Characteristics:includes both of the genes that code for one traits, even if one of these genes is masked.
- Classification:homozygous/heterozygous
- Function:determines phenotype
- DNA polymerase
- Definition: is a group of enzyme that bond the new nucleotides together
- Function: can form bond between nucleotides during replication
- Position: moves along a DNA strand
- Characteristics: it needs a primer; from 5’ to 3’ direction
- Bacteriophage:
- Definition: is a type of virus that can infect bacteria
- Components: protein coat + DNA
- Ways to infect: adhere to the bacteria . Inject the DNA, copy DNA and protein,
- Primer:
- Definition: short, single strand DNA or RNA that serves as an attachment point for DNA polymerase
- Production: another enzyme( primase )starts making them after DNA strands are separated
- Function: exposed nucleotide bases on a single strand of DNA form hydrogen bonds with complementary bases of primer
- Semiconservative replication:
- 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
- Purpose: assures that every cell has a complete set of identical genetic information
- Time: during S(synthesis) stage of the cell cycle
- Phenotype:
- Definition: the physical characteristics, or traits of an individual organism make up it.
- Expression in different individuals:Recessive/Dominant character
- Characteristic: determined by genotype; the phenotype is for visible traits, the hidden genes doesn’t matter to this phenotype.
- Segregation of characters:
- Definition:The offspring emerges an new trait that haven’t shown among its parents.
- Application: the new appearing character must be recessive trait
- Characteristic: parents must be heterozygous
- Foundation: law of segregation
- Homozygous:
- Definition:it describes two same alleles at a specific locus.
- Characteristic: the genes in two locus of a pair of homologous chromosomes are the same
- Relationship with allele: only have recessive/dominant allele
- Heterozygous
- Definition:it describes two different alleles at a specific locus.
- Characteristic: the genes in two locus of a pair of homologous chromosomes are different
- Relationship with allele: Have both Recessive/ Dominant allele
- Multiplication rule:
- Definition: multiply the probability of each event
- Function:the calculate the probability that two independent events will happen together
- 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
- Addition rule
- Definition: plus the probability of each event
- Function:the calculate the probability that one of the independent events will happen.
- Application: to calculate the probability of the offspring that will be heterozygous/ homozygous