DNA

Nucleic Acids

Nucleic Acids

What are the building blocks of DNA?

Nucleic Acids

Long, slightly acidic molecules originally found in cell nuclei

Nucleotides

Make up nucleic acids, linked together to form long chains

Adenine

Type of nucleotide (A)

Guanine

Type of nucleotide (G)

Cytosine

Type of nucleotide (C)

Thymine

Type of nucleotide (T)

T

A always goes with…

G

C always goes with…

A

T always goes with…

C

G always goes with…

Purines

Nucleotide (hexagon+pentagon)

Prymidines

Nucleotide (hexagon)

Chargaff’s Rule

The percent of A=T and G=C

Rosalind Franklin

Used a technique called Xray defraction to find the structure of DNA

Double helix

Structure of DNA

Watson and Crick

Who discovered DNA?

Building models

How did Watson and Crick discover DNA?

Double helix

2 strands in a spinning, spiral ladder

Hydrogen bonds

The 2 strands of DNA are held together by…

Base pairing

The nucleotide of one strand bonds with the corresponding nucleotide on the other strand

DNA to RNA to protein

Central dogma of Biology

DNA Helicase

Enzyme the splits the double helix into 2 strands that are complimentary

DNA Polymerase

Enzyme that starts to build the complimentary nucleotides onto the seperate strands

Telemerase

Enzyme that makes telomeres, adds DNA back to the telomeres to protect the information

5’ to 3’

Polymerase only works from…

Primase

Enzyme that starts the copy of DNA so polymerase knows where to start building

Leading strand

5’ to 3’

Polymerase starts building DNA on it very fast

Lagging strand

Polymerase has to wait for a primer to make a DNA base that goes from 5’ to 3’

Okazaki fragments

Fragments of DNA that polymerase builds in between the primers

Exonuclease

Enzymes that removes the primers so that polymerase can build in those spots

Ligase

Enzyme that seals up the 2 strands on DNA

Semi-conservative

DNA replication is ________

This means that one strand is conserved from the old DNA and one is newly built

Gregor Mendel

Father of Genetics

Pea plants

What did Mendel study?

Fertilization

Plant sex

1) Bees go into flowers for necter

2)The pollen sticks to the bees

3) The pollen gets dropped off into the next flower the bee goes into

Cross pollination

When plants get pollinated with pollen from a different plant. This produces more diversity.

Trait

A specific characteristic of an individial (ex: eye color, height, nose shape, etc)

True breeding

Self pollinating, produces offspring with identical traits to the parents

Cross breeding

When you make 2 distinct true breds breed with each other

Hybrid

Offspring of the crosses between parents with different traits (product of cross breeding)

Genes

Factors passed from parents to offspring (category)

Alleles

Forms of a gene (trait)

Mendel’s 1st principle

An individiual’s characteristics are determined by the factors passed down from their parents

Principle of dominance

Some alleles are more dominant and others are recessive. This is Mendel’s 2nd principle.

2

Each gene has how many alleles?

True

The organism will always show the DOMINANT trait unless it has 2 recessives. (True/False)

Gametes

Sex cells (eggs and sperm)

Law of Segregation

When they’re made, 2 alleles seperate. There are 2 kinds, dominant and recessive, but only one is passed on from each parent.

Punnett sqaures

How we represent the way alleles are passed down (in letters and probability)

Probablity

The likelihood that a paticiular event will occue

Homozygous

Organisms that have 2 identical allels for a paticular gene (TT or tt)

Heterozygous

Organisms that have 2 different alleles for a paticular gene (Tt)

Phenotype

Physical trait (manifestation of the genotypes)

Genotype

Genetic makeup (homozygous dominant/recessive or heterozygous)

Dihybrid

2 factor cross

Principle of Independent assortment

Genes for different traits can segregate independently during the gamete formation. In other words, the inheritance of genes are not connected. Mendel discoverd this from dihybrid crossing.

Heterozygous

Homozygous Dominant x Homozygous Recessive=

Incomplete Dominance

1 allele isn’t completely dominant over the other. The heterozygous is a MIX.

Incomplete Dominance

Examples of what alternate pattern of inhertiance?

Red flower x white flower= pink flower (Snap-dragons)

White spotted dog x black dog= gray spotted dog (dalmations)

Codominance

When the phenotypes produced by the alleles are both clearly expressed

Codominance

Examples of what alternate pattern of inheritance?

Black chicken x white chicken= black and white speckled chicken

Brown cow x White cow = brown and white spotted cow

Multiple alleles

A gene with more than 2 alleles is said to have _______ ____

Multiple alleles

Example of what type of alternate pattern of inheritance?

Blood types, rabbit fur

Polygenic traits

Traits that are controlled by 2 or more genes. Shows a wide range of phenotypes

Polygenic traits

Example of what kind of alternate pattern of inhertiance?

Skin colors

Multiple alleles and polygenic traits

In humans, what types of alternate patterns of inhertiance are the most prevelant?

Sex linked inheritance

Traits that are found on the sex chromosomes. Affects men more than women since women have a back up X chromosome

Sex linked inheritance

Examples of what kind of alternate pattern of inheritance?

Red/green color blindness, baldness, myopia, hemophilia, and night blindness

Pedigrees

A genetic family tree that shows how prevelant a trait is in a family from generation to generation. They are often used to trace the expression of genetic conditions/disorders.

Squares

On a pedigree, men are represented by _______

Circles

On a pedigree, women are represented by _______

Carrier

On a pedigree, a ½ shaded shape means that person is a ______. They carry the alleles for that recessive trait.

Affected

On a pedigree, a fully shaded shape means that person is ________

Autosomal dominance inhertiance

Autosomes (Chromosomes 1-44)

Refers to situations in which a single copy of an allele is enough to cause the expression of a trait.

Examples: progeria, huntingtons

Enviroment

The characteristics of an organism are affecetd by both genes and its _________