General Biology 2 Finals

Genetics

Genetics

a branch of biology that deals with heredity and variation of organisms

GREGOR MENDEL(1822-1884)

Father of modern genetics

GREGOR MENDEL(1822-1884)

An Austrian botanist and an Augustinian monk in the monastery of St. Thomas in Brun (now Bruno, in the Czech Republic), teacher, and biologist.

ALLELE

One of two alternative forms of a gene; any of the alternative forms of a gene that may occur at a given locus

DOMINANT TRAIT

Trait that is expressed; relating to a characteristic or condition that a child will have if one of the child’s parents has it

F₁ GENERATION

“first filial” or first generation of offspring

F₂ GENERATION

Generation produced by interbreeding individuals of the F₁ generation

GAMETE

Reproductive or sex cell; one of the cells that join together to begin making a person or other creature

GENOTYPE

Genetic composition of an individual

HETEROZYGOUS

Organisms that have two different alleles for the same trait

HOMOZYGOUS

Organisms that have two identical alleles for a particular trait

PHENOTYPE

Observable characteristics of an individual

PUNNET SQUARE

Diagram used to predict an outcome of a particular cross or breeding

RECESSIVE TRAIT

Trait that is masked in the presence of a dominant trait

Punnett square

used in genetics to calculate the frequencies of the different genotypes and phenotypes among the offspring of a cross

Monohybrid cross

Parents differ by a single trait

Dihybrid Cross

determines the genotypic and phenotypic combinations of offspring for two particular genes that are unlinked

Genotype

refers to the entire set of genes in a cell, an organism, or an individual.

Phenotype

the physical appearance or other characteristic of an organism as a result of the interaction of its genotype and the environment.

Law of Segregation

Law of Independent Assortment

Law of Dominance

LAWS OF INHERITANCE

Law of Segregation

When gametes are formed, the pairs of hereditary factors (genes) become separated, so that each sex cell (egg/sperm) receives only one kind of gene

Law of Independent Assortment

“Members of one gene pair segregate independently from other gene pairs during gamete formation”

Law of Dominance

One allele masked another, one allele was dominant over the other in the F1 generation.

INCOMPLETE DOMINANCE

CODOMINANCE

Non-Mendelian

Incomplete Dominance

Form of Gene interaction in which both alleles of a gene at a locus are partially expressed, often resulting in an intermediate or different phenotype. It is also known as partial dominance

Codominance

In codominance, both alleles contribute to the phenotype of an organism

PEDIGREE CHART

it is one of the important tools in studying human genetics and patterns of inheritance

PEDIGREE CHART

it uses symbols that show one’s family history

PEDIGREE CHART

it also shows the family relations and the phenotypes of each member.

SEX LINKAGE

special pattern of inheritance

SEX LINKAGE

applies to genes located on the sex chromosomes

SEX CHROMOSOMES

determine if an individual is male or female

KARYOTYPE

The chromosomes of a cell, systematized arrangement of chromosome pairs in descending order of size.

X chromosome

Different kinds of sex-linked genes are found on the

COLOR BLINDESS

COLOR VISION

DUCHENNE MUSCULAR DYSTROPHY

HEMOPHILIA

Sex x-linked genetic disorder

TRICHOMACY

ANOMALOUS TRICHOMACY

DICHROMACY

MONOCHROMACY

TYPES OF COLOR BLINDESS

TRICHOMACY

Normal color vision uses all three types of light cones correctly and is known as trichromacy.

ANOMALOUS TRICHOMACY

People with ‘faulty’ trichromatic vision will be color blind to some extent

DICHROMACY

have only two types of cones which are able to perceive color.

MONOCHROMACY

can see no color at all and their world consists of different shades of grey ranging from black to white, rather like only seeing the world on an old black and white television set.

PROTANOPIA

DEUTERANOPIA

TRITANOPIA

Protanomaly

Deuteranomaly

Tritanomaly

TYPES OF COLOR VISION

PROTANOPIA

unable to perceive any ‘red’ light

DEUTERANOPIA

unable to perceive any ‘green’ light

TRITANOPIA

unable to perceive any ‘blue’ light

Protanomaly

a reduced sensitivity to red light

Deuteranomaly

a reduced sensitivity to green light and is the most common form of color blindness

Tritanomaly

a reduced sensitivity to blue light and is extremely rare

DUCHENNE MUSCULAR DYSTROPHY

A genetic disorder characterized by progressive muscle degeneration and weakness

HEMOPHILIA

this disorder related to blood clotting

Central Dogma

-It is the basic underlying principle in the field of Genetics.

-This explains that DNA codes for RNA, which codes for the proteins.

DEOXYRIBONUCLEIC ACID

RIBONUCLEIC ACID

PROTEINS

COMPONENTS OF CENTRAL DOGMA OF LIFE

DEOXYRIBONUCLEIC ACID

is the genetic material passed on from parents to offspring. It contains the instructions necessary for the survival of every organism.

deoxyribose

The sugar group in the DNA

Purines

-adenine and guanine

-have doubled-ring structure

Pyrimidines

-cytosine, thymine and uracil

-contain only one ring in their structure

RIBONUCLEIC ACID

is a single stranded molecule that is also composed of nucleotides with a few modifications.

ribose

The sugar backbone of RNA

Messenger RNA (mRNA)

Translates the genetic code into protein with the help of ribosomes

Transfer RNA (tRNA)

helps in transferring amino acids to the correct sequence in mRNA

Ribosomal RNA (rRNA)

structural component of ribosome

PROTEINS

These are the final products of central dogma of molecular biology.

PROTEINS

also called the “building blocks of life”

PROTEINS

are composed of polymers of numerous amino acids known as “polypeptides”.

genetic code

The language of instruction

codon

read using a combination of only three letters at a time

DNA REPLICATION

The DNA molecules separate into two complementary strands. Both can serve as a template for the new strand.

DNA REPLICATION

Enzymes unzip DNA molecules by breaking down the hydrogen bonds between base pairs.

helicase

unwinds and separates the DNA into two single strands.

RNA primase

binds the RNA nucleotides to 3’-5’ parent strand.

primers

temporary complementary base pair that is attached to the two-template strand of DNA in aid of the replication process

adenine and thymine

origin of replication

DNA polymerase

adds DNA nucleotides to the 3’ end of the newly synthesized strand.

DNA polymerase

it gives the complementary base pair for the two-template strand of DNA during the elongation process in replication.

exonuclease

strips the RNA primers away

ligase

seals up the sequence into two continuous double strands, resulting in two DNA molecules

DNA TRANSCRIPTION

The process by which RNA is synthesized from DNA

RNA polymerase

binds to DNA, separating the DNA Strands.

promoters

RNA polymerase binds at this1 specific sequence in the DNA nucleotides

Elongation

-happens when different nucleotides from cytoplasm are added to growing RNA chain.

-RNA is also synthesized in the 5’-3’ direction.

INITIATION

-Requires an RNA polymerase, which is similar to DNA polymerase.

Termination

-happens when RNA polymerase reaches the terminator site which contains a specific sequence of nucleotides that signals the end of transcription.

DNA TRANSLATION

Happens when the message carried by the mRNA is decoded into a protein or a polypeptide chain.

anticodon

complementary base pair of the codons in the mRNA transcript that is being delivered by the tRNA

Initiation

Where mRNA transcribed inside the nucleus is released into the cytoplasm.

Elongation

Is the formation of the growing polypeptide chain by bringing in the proper tRNA to translate the mRNA into a protein.

Termination

continuous attachment of tRNA to the mRNA allows the polypeptide chain to elongate until it encounters a stop codon (UAA, UAG, or UGA), which terminates and completes the process of translation.

Stewart Linn and Werner Arber (1960)

discovered restriction enzymes known as endonucleases.

Endonucleases

cut DNA at specific sites where there are adjacent base sequences. They also create sticky ends on the cut DNA sites, allowing certain DNA fragments to be joined together.

Boyer and Cohen in 1973

developed Recombinant DNA technology

Stanley Cohen (1935)

who received the Nobel Prize in Medicine in 1986 for his work on discoveries of growth factors.

Herbert Boyer (1936)

who constructed the first recombinant DNA using bacterial DNA and plasmids.

recombinant technology

allows DNA to be produced via artificial means.

Genetic Engineering

is a process of making changes on the genetic code of an organism.

DNA Recombination

is a process of modifying the genes of organisms for practical purposes. It is done when a piece of DNA is combined with another DNA from another source. and the resulting genetic product is called recombinant DNA.

Polymerase chain reaction (pcr)

DNA SEQUENCING

TECHNOLOGIES AND TOOLS USED IN RECOMBINANT DNA TECHNOLOGY

Polymerase chain reaction (PCR)

is a commonly laboratory technique used to make many copies of a particular region of DNA. This DNA region can be anything the experimenter is interested in.

Primers

are short strands that provide a place for the DNA polymerase to start working.

DNA SEQUENCING

Is a method used to provide the identity and order of nucleotides in a DNA strand.

Vectors

is the means by which DNA from another species can be carried into the host cell.

Plasmid

a selected portion of the foreign DNA is inserted into a small, circular DNA molecule in the transformation process which is naturally found in bacteria.