Definition of species
A group of organisms which can reproduce to produce fertile offspring.
Have common genetic, biochemical, physiological, an atomic features.
Definition of classification
The process of sorting organisms into groups based on similarities and differences.
Why do scientists classify organisms?
- to identify species
- to predict characteristics
- to find evolutionary links
What is the biological species concept?
Defines species as a group with similar morphological, physiological, behavioral, biochemical and ecological features.
Can interbreed with each other to produce fertile offspring.
What is the phylogenetic species concept?
Defines a species as the smallest group that shares a common ancestor.
What is the hierarchy of classification?
Domain Kingdom Phylum Class Order Family Genus Species
What is binomial nomenclature?
- the naming system used for classification
- first part of the name is the genus
- second part of the name is the species
Advantages of the international binomial name
- avoids confusion between countries
- avoids ambiguity
Types of adaptations
1 . Anatomical - physical structure 2 . Behavioral - simple reflex response 3. Physiological - biochemical or cellular characteristics
Anatomical adaptations in humans
- Bipedalism
- walking on 2 feet
- allows for tool use
- greater ability to hunt - Brain size
- tripled over the course of human evolution
- more complex info can be processed.
- greater ability to adapt to changing environment
Behavioral adaptations in humans
- Tool use
- improved hunting
- ability to obtain high protein and high energy diet - Social adaptations
- behavior helps maintain larger social groups.
Physiological adaptations in humans
- Lactose tolerance
- source of calcium - Skin pigmentation
- loss of body hair
- provides protection from dangerous UV radiation
Adaptations to temperature in plants
- low growing (minimize risk of freezing.)
- dark in color (help absorb radiation)
- disk shaped flowers (focus heat from the sun)
Adaptations to water in plants
- close stomata when water is limited
- close stomata at the hottest points of the day
- spread long roots over wide area
- hairs on epidermis
- thick waxy cuticle
Adaptations to light in plants
- air spaces in tissues
- seeds and stems contain air spaces
- leaves and stems are flexible
- plants in deeper waters have specialized photosynthetic pigments to absorb specific wavelengths of light.
Adaptations to mineral concentration in plants
- obtain nitrogen from animals they trap and digest
Genetic causes for variation
- Mutations
- changes to DNA sequences - Alleles
- different forms of genes - Meiosis
- random assortment of chromosomes and chromatids in metaphase 1 and 2
- crossing over - Sexual reproduction
- selection of mates is random
- fertilization is random
Environmental causes for variation
Biotic and abortion factors
E.g. light availability, nitrates available
What is a selection pressure?
An environmental factor that drives evolution in a particular direction.
Process of natural selection
- Variation is present within the original population.
- New allele arrives due to mutation
- Selective advantage have increased chances of survival
- Less advantaged will die of or fail to reproduce
- Overtime population will have the selective advantage
What is allopatric speciation?
Caused by geographical isolation.
Different population experience different selection pressures.
What is sympatric speciation?
Caused by reproductive isolation.
Unable to reproduce successfully with each other.
Evidence for evolution
- Palaentology
- study of fossils and fossil records. - Comparative anatomy
- study of similarities and differences in anatomy - Comparative biochemistry
- similarities and differences between the chemical makeup of organisms - Archeological artifacts
- Computer similarities
Evolution of Hominids
- increased brain size
- increased leg length
- bipedalism
- enlarged heels
- upright body position
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Chapter 1 - Cells and Microscopy25
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Chapter 2 - The importance of water12
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Chapter 3 - Proteins and Enzymes28
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Chapter 4 - Nucleic Acids14
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Chapter 5 - The heart and Monitoring heart function25
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Chapter 6 - Transport systems in mammals and plants5
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Chapter 7 - Mammalian Gas Exchange0
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Chapter 8 - The Developing Cell23
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Chapter 9 - Meiosis, growth and development0
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Chapter 10 - Evolution and Classification36
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Chapter 11 - Diseases12
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Chapter 12 - Immunity17
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Chapter 13 - Communicable Diseases24
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Chapter 14 - Non-Communicable Diseases14
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Chapter 15 - Respiratory Diseases20
