A3 Diversity

Classification of Organisms Criteria

Classification of Organisms Criteria

• Feeding habits

• Habitats

• Movement

• Risk

• Anatomy

• Daily Activity

Discontinuous

Distinct Categories

Continuous

Wide range of possibilities

Taxon

Boxes of classification

Domain

Largest Taxon

Binomial Naming System

Linnaeus

first name = genus

second name = species

Objectives of binomial naming system

1. Unique name so no confusion

2. Universal understanding

3. Stability (no random name changing)

Biological Species Concept

Mayr 1942

Same species requires individuals to breed together and produce fertile offspring

Characteristics of what counts as a species

• ecological niche

• genetics types of molecules

• types of molecules an organism can produce

• extinct species lineages

Speciation

Process where population is separated in 2 groups that can no longer reproduce

Diploid

Nucleus that has chromosomes in double (homogenous) pairs

Haploid

Nucleus with singular chromosomes

These are gametes

Characteristic of species

# of chromosomes

Not all cells have chromosomes like red blood cells

Karyotypes

Representation of chromosome found in a cell arranged by a standard format

Placed according to shape and size

Process of karyogram

1. Cells strained, prep on a glass slide to see chromosome in light microscope

2. Photomicrograph obtained of chromosome during mitotic phase (division phase)

3. Image cut out and separated

4. Placed in decreasing length size

Evolution of chromosome 2 theories

1. complete chromosome disappeared

2. 2 chromosomes from earlier common ancestor fused to become 1

Evidence for second theory

Positioning of centrosome in the middle (metacentric chromosome) suggest fusing of 2 other chromosomes

Similarities in banding patterns

• Long arm of human chromosome 2 has similar banding patterns to long arm of chromosome 12 with a common ancestor of chimpanzee

• Arm of human chromosome 2 has similar banding pattern with chromosome 13 with a common ancestor of chimpanzee

Repeating sequences of telemetric DNA in human chromosome 2

• present at tips

• also present in the center (fusing of two other chromosomes)

Alleles

Different versions of existing genes

Single Nucleotide Polymorphism

(SNP) varies in base pairs

around 100 - 300 contain SNP

• help determine ancestry or risk of genetic disease

5% of SNP’s are dangerous most are neutral and dont impact phenotype

Phenotype

Physical expression of a gene

Human Genome Project

Venture set out to sequence the entire human genome

Map to show positioning of genes

Ways to compare genetic diversity in eukaryotes

Through mitochondrial DNA

Genetic Differences

Expressed in amino acid sequence coded for by an organisms DNA

Comapring Genetic Differences

• DNA Code

  or

• Amino acid sequences

Phylogenetic

Comparison of whole genome sequence to understand relation of organism

Benefits of genenome sequencing in medicine

• information about a persons genetic makeup to be applied when prescribing treatments

• Increase efficiency of treatments relating to certain genetic sequence

  • better for dynamic diseases

• Decrease undesired side effects

Advantages of use of human genome

Find beneficial molecules produced naturally in people

Which gene controls synthesis for a desirable molecule

Copy of genes + using it to instruct synthesis in labs

Distribute beneficial therapeutic protein as a new medial treatment