Biological diversity

its 3am guys.

Mammals  

• Posses hair 

• Three middle ear bones 

• Neocortex (region of the brain) 

• Brain regulates body temperature and circulatory system 

Variation within species

Differences in characteristics of organisms caused by genetic and environmental factors 

Species  

• A group of organisms that share similar characteristics 

• Generally, organisms can interbreed and produce fertile offspring  

Adaptation 

• Evolutionary process 

• Organisms have a higher chance to live and reproduce in it’s habitat 

• Identified as structural or behavioral  

• Ex: natural selection 

Structural adaptation and behavioral adaptation 

• structural: An inherited physical characteristic 

• behavioral: An inherited characteristic behavior 

Ecosystem  

living organisms and abiotic factors interacting that are living in an ecological community 

Ecological community 

All organisms of all species that inhabit and interact in geological area 

Ecological niche 

species use of biotic and abiotic resources

Generalist  

• Organism with generalized requirements 

• Adaptations that allow it to survive in various conditions 

• Depend on variety of food source 

• Broad niche 

Specialist  

• Organism adapted to very specific environments 

• Narrow niche 

Specialization  

adaptations for surviving in very specific environments 

Variation 

• Refers to a distribution in genetics within a species 

• Ex: chromosomes, DNA 

symbiosis  

• Interaction between different species living near each other in a relationship that lasts over time 

• Can be positive, negative, or neutral 

Commensalism  

One organism benefits, the other is unaffected 

Mutualism 

Both organism benefit  

Parasitism  

One partner benefits, while the other is harmed 

Reproduction 

• Produces new individual of a species 

• determines the variation it will have 

• Can be identical or different 

Asexual reproduction 

• Only one parent 

• All offsprings identical to parent 

• Same characteristics 

Binary fission  

• Single celled organisms 

• Cell splits exactly into two, making them identical 

Budding  

• Parent produces a small bud, smaller version of itself 

• Eventually detaches and becomes a new individual, identical to parent

Spore reproduction 

• Produced by division of cells of the parent 

• Individual will produce many of them, each will develop into a new individual 

Vegetative  

• In plants that does not require seed 

• Runners  

• Tubers  

Sexual reproduction 

• Involves two parents 

• Offsprings will be mixed throughout each generation 

• Join gametes  

• New individuals share traits from both parents 

• Will not be identical to parents 

Gametes 

• Reproductive cells 

• form zygote 

• Female – ovum 

• Male – sperm 

Fertilization  

• male and female gamete join to make a zygote  

• 1N -> 2N 

Zygote 

Cell created by two gametes joining together 

Embryo 

• Result of continued cell division 

• Multicellular life 

• Developed in female 

Reproduction process

Female gamete + male gamete -> fertilization -> zygote -> cell division (cleavage) -> continued cell division -> embryo 

Haploid  

• N 

• one set of chromosomes 

• half 

Diploid  

• 2N 

• two sets of chromosomes 

Somatic  

Other cells that are not reproductive 

Mitosis 

• Cells multiplying 

• 2N -> 2N 

• Non-reproductive - cell division in all multicellular organisms 

• All organisms (ex: skin cells) 

• Reproductive – some unicellular and multicellular organisms 

Meiosis 

• Cell division  

• 2N -> 1N 

• Only reproductive 

Sexual reproduction in plants 

• Male gamete and female gamete joining to make zygote 

• Some with female and male, some just female, some just male 

• Some characteristics of both parents 

• Not identical 

• New embryo may not begin to grow 

• Embryo produced in a seed 

plant gametes

• pollen

  • Male gamete 

  • Found in stamen 

• ovules

  • Female gamete 

  • Found in pistil 

Pollination 

• Pollen transferred to another plant 

• Fertilization – male and female gamete fuse 

Natural selection and Artificial selection 

• Natural selection 

  • Happens within ecosystem 

  • No human intervention 

• Artificial selection 

  • Humans choosing the traits 

Genetic material

All inherited genetic characteristics are determined by info coded in DNA 

Hierarchy (largest to smallest) 

Chromosome -> alleles -> genes -> DNA  

DNA, chromosome, allele, gene 

• DNA 

  • Passed down from parent to offspring

• chromosome

  • Structure found inside the nucleus of a cell 

  • Carry DNA instructions for some trait or characteristic allele 

• allele

  • Matching genes together – grouped 

  • Determines characteristics 

  • One dominant  

  • One recessive  

• gene

  • Passed down from parent to offspring 

  • One gene -> one trait 

Dominant allele and recessive allele 

• Dominant allele 

  • Characteristic that will be expressed even when present on only one parental chromosome 

• Recessive allele 

  • Characteristic that will be expressed only when present on both parental chromosomes 

Pure-bred and mix-bred

• Pure-bred 

  • One allele 

• mix-bred

  • two alleles 

Phenotype and genotype  

• Phenotype

  • visible

• genotype

  • Not visible 

  • Two alleles 

  • Ex: Bb 

Homozygous  

• Both alleles are the same  

• BB = brown eye alleles – homozygous dominant 

• bb = blue eye alleles – homozygous recessive 

Heterozygous  

• Both alleles are different 

• Bb = brown and one blue eye allele 

Co – dominance and incomplete dominance 

• Co – dominance 

  • two dominant traits 

• Incomplete dominance 

  • Dominant allele isn’t strong enough to mask recessive, so some recessive traits visible 

  • Some traits are caused by multiple genes 

Mendelian and non – mendelian 

Mendelian 

• one allele, one trait 

• Doesn't cover blood type or eye color 

Non – mendelian 

• multiple dominance, or multiple allele influence