Bio U5 Flashcards
Formation of glucose (photosynthesis)
6CO2 + 6H2O ➡️ C6H12O6 + O2
What is a morphogen
Substance that governs the pattern of tissue development by activating the homeobox genes
What are transcription factors
Polypeptides expressed by homeobox genes that bind to other genes further along the DNA from homeobox genes and switch them on
Influence the development of the embryo
Maternal effect genes
Determine the embryos polarity
Segmentation genes
Determine the polarity of each body segment
Define mutation
Change to the base sequence of DNA
Define mutation
Change to the base sequence of DNA
Gene
Sequence of DNA coding for a single polypeptide
Allele
Different version of a gene
Genotype
Alleles an organism has
Phenotype
Characteristics produced by alleles
Observable characteristics
Dominant
Allele whose characteristics appear in the phenotype even if it’s one copy
Shown by a capital letter
Recessive
Allele who’s characteristics are shown in the phenotype if there are two copies
Shown by lower case
Codominant
Alleles both expressed in the phenotype
Neither one is recessive
Locus
Fixed position of a gene on a chromosome
Alleles of a gene are found at the same locus on each chromosome in a pair
Homozygote
Organism that carries two copies if the same allele
Heterozygote
Organism carrying two different alleles
Bb
Carrier
Person carrying an allele which is not expressed in the phenotype but can be passed on to the offspring
Monohybrid phenotypic ratio
3:1
Dihybrid phenotypic ratio
9:3:3:1
Codominant phenotypic ratio
1:2:1
Epistatic recessive allele ratio
9:3:4
Dominant Epistatic allele ratio
12:3:1
Epistasis
Interaction of genes concerned with the expression of one characteristic
One gene may mask the expression of another gene
Continuous variation
Individuals in a population vary within a range
No distinct categories
Discontinuous variation
Two or more distinct categories
Each individual falls into ONE category -there are no intermediates
Homeotic selector genes
Specify the identity of each segment and direct the development of individual body segments
Hardy Weinberg principle
Predicts the frequency of alleles in a population won’t change from one generation to the next
Only true if: Large populations No immigration No emigration No mutations No natural selection Needs to be random mating
Hardy Weinberg equation to predict allele frequency
p+q=1
p=frequency of dominant allele
q=frequency of recessive allele
Hardy Weinberg equation to predict the genotype frequency
(p) 2+2pq+(q)2=1
(p) 2= frequency of the homozygous dominant genotype
2pq=frequency of heterozygous genotype
(q)2= frequency of homozygous recessive genotype
What is p stand for in the hardy Weinberg principle for allele frequencies
Frequency for dominant allele
What does q stand for in the hard Weinberg principle for allele frequencies
Frequency of recessive allele
p2 for genotype frequencies
Frequency of homozygous dominant genotype
2pq for genotype frequency
Frequency for heterozygous genotype
q2 for genotype frequency
Frequency for homozygous genotype
Species
Group of organisms that can breed to reproduce fertile offspring
Speciation
Development of a new species
When does speciation occur
When populations of the same species become reproductively isolated
Phylogenetics
The study of the evolutionary history of groups of organisms
Cloning
Process of producing genetically identical cells or organisms from cells of an existing organism
Reproductive cloning
Cloning used to make a complete organism genetically identical to another organism
Non reproductive cloning
Cloning used to make embryonic stem cells that are genetically identical to another organism
Advantages of cloning
Desirable genetic characteristics are always passed on to clones
Infertile animals can reproduce
Animals can be cloned at any time
Disadvantages to cloning
Undesirable genetic characteristics are always passed on
Reproductive cloning can be time consuming, expensive, and difficult
Clones may not live long
What are ethical issues with human cloning
Embryos are destroyed after harvesting the stem cells which is beloved by some to be destroying a human life
Cloned humans may have a lower quality of life
Cloning humans undermines natural sexual reproduction and traditional family structures
Vegetative propagation
Natural production of plant clones from non-reproductive tissues
Advantages of plant cloning
Desirable characteristics are ways passed on
Plants can reproduce in any season because tissue culture is carried out indoors
Sterile plants can be reproduced
Plants can reproduce quickly
Disadvantages of plant cloning
Undesirable genetic characteristics are always passed on
Cloned populations have no genetic variability
Production costs a very high due to high energy use and training workers
Outline artificially cloning through nuclear transfer
Body cell take from sheep A-nucleus extracted and kept
Egg cell is taken from sheep B and enucleated
Nucleus from A is inserted into enucleated egg cell from B
Egg cell stimulated to divide
In REPRODUCTIVE CLONING embryo is implanted into surrogate mother. Offspring produced genetically identical to A
In NON-REPRODUCTIVE CLONING stem cells are harvested from the embryo. Stem cells are genetically identical to A
How is bacteria used to produce human insulin
Gene for human insulin is identified and isolated using restriction enzymes
Plasmid is cut open using the same restriction enzymes that’s was used to isolate the insulin gene
The insulin gene is inserted into the plasmid and form RECOMBINANT DNA
Plasmid is take up by bacteria and any transformed bacteria are identified using marker genes
Bacteria is grown in a fermenter and human insulin is produced as they grow and divide
The human insulin is extracted and purified for human use
Outline the process used to make golden rice
psy gene and crtl gene are isolated using restriction enzymes
Plasmid is removed from the agrobacterium tumefaciens bacterium and cut open with the same restriction enzymes
Psy, crtl and a marker gene are inserted into the plasmid
The recombinant plasmid is put back into the bacterium
Rice plants are incubated with the transformed a. Tumefaciens bacteria which infect the rice plants
A. Tumefaciens inserts the gene into the plant cells fan creating transformed rice plant cells
Rice plants are grown on a selective medium where only transformed rice plants will be able to grow because they contain the marker gene needed to grow on this medium
Xenotransplantation
Transfer if cells, tissues, or orphans from one species to another
Ecosystem
All organism living in a particular area and their non-living conditions
Habitat
Place where and a organism lives
Population
All the organisms of one species in a habitat
Abiotic factors
Non living ratites of the ecosystem
Biotic factors
Livin features of the ecosystem
Producer
An organism that produces organic molecules using sunlight energy
Consumer
Organism that eats other organisms
Decomposer
Organism that breaks down dead or undigested organic material
Trophic level
A stage in a food chain occupied by a particular group of organisms
