Cells and Evolution (Bio 11)

Organisms

• Any living thing

• Can be unicellular or multicellular

Organism needs (4)

Water - carry out cellular activity

Nutrients - provides organism need to grow

Space to Live - place to get food, water and shelter

Air - plants need CO2 and animals need O2

characteristics organism (8)

Cells. Homeostasis. Energy. Reproduce. Traits. Grow. Respond. Change.

Uni vs. Multi cellular

Uni - simple, single called (which carry out all functions) - can be prokaryotes and eukaryotes. - no cellular specialization

Multi - complex, many called. - cells developed differently so they have different appearance for specific function.

Homeostasis

Ability to maintain internal conditions in response to environment

Energy currency

Andenosine triphosphate (ATP)

(Organism characteristic - respond) stimulus - internal vs. external

Response = Action

Is activity that brings response (action)

In - inside

Ex - outside

Levels of organization

Cells —> Tissues —> Organs —> Organ system

Cell (organization)

• Specialized cells carry out specific functions

• Smallest unit of life

Tissues (organization)

Group of cells with similar shape and function

Organs (organization)

Tissues that are organized into large structures that have 1 function

Organ system (organization)

Group of organs that have related functions

Prokaryotes

• Simple unicellular organisms

• All are bacteria

• No membrane bount organells ( no nucleus)

Eukaryotes

• Complex organisms (most living things)

• Can be unicellular or multicellular

• Contains orgenelles surrounded by membrane (has nucleus)

Structure vs. Function

• Structure = appearance

• Function = job

Cell specialization

• Cells specializes to perform specific functions

• Beacuse of cell differential

• Happens only in multicellular organism

Cell specializaion examples (3)

• Neurons - send info from 1 body part to another. - shape —> long and thin

• Red blood cell - cary oxygen through bloodvessle - shape —> flat disck

• Sperm cell - fertalize egg cell. - shape —> stong tail to swim and head to enter egg cell

Cell differentiation

• The process of which cells develop differently

• Result of gene expression (gene on or off)

• Cells only use needed info

Sperm cells (cell diffrentiation)

Can become any cell in body beacuse it havent undergone cell differentiation

Adaptation

• Characteristics that help organism survive and reproduce

• Can be structural and behaviour to find food, mate, shelter, and movement

Adaptations examples (6)

• snake —> smells with tounge

• kangaroo —> strong heind legs to jump far

• spider —> easily sence vibrations

• monkey —> oposable thumbs

• lepord —> teeth for eating meet

• elephant —> trunks to drink water

Orgin of species hypothesis l

• Anestotle

• Believe all plants and animals been placed on earth at begining and nothing changed

• Lasted 2000years

Orgin of species hypothesis ll

• Life changed over time

• 2 major theories by Lemarck and Darwin

Lamarck's Theory (origin of species)

• Law of use and disuse - more use means more developed.

• Inheritance of acquired characteristics - more developed (or undeveloped) traits pass to children

Darwin's theory (origins of species)

• Evolution happened beacuse of natural selection where highly suited characteristics to environment have greater survival and reproduction rates

Natural selection (4 conditions)

1) struggle for survival - result in not all survive

2) inheritable variation (DNA) - different traits in same population. - inheritable traits get passed down

3) variation of fitness - ability reproduce and pass down good genes

4) lots of time - gradual change (at least 100 years)

Evolution

Process of gradual change over many generations in physical and behaviour characteristics

Speciation

Formation of new distinct species

• 2 organism of distinct —> infertile offspring

• 2 organism of same —> fertile offspring

3 types of evolution

1) convergent - 2 or more species share similar genes (no common ancestors. - live in similar environment = similar characteristics

2) divergent - 2 or more species diverge from common ancestor. - become isolated and adapt to new environment

3) coevolution - 2 or more species influence eachothers evolution bescuse of interaction

Inheritable mutations

• Change to DNA in germ cell that gets passed down

Mutation (and 3 types)

• New allele in new populations, leading to gene variation

• Occur from radiation, chemical, and through DNA replication

• 1) beneficial - positive impact on survival

• 2) harmful - negative impact on survival

• 3) neutral - no effect on survival

Gene pool

• All alleles in 1 population

• Where genetic variation is stored

Gene flow

• Exchange between 2 populations (same species)

• Result in increase in genetic variation in both populations

Genetic drift

• Change in gene pool due to random change

• Major effect on small population

Genetic bottleneck vs. Founders effect

1) genetic bottleneck - during natural disasters significantly reduce population. - Surviving alleles changed Gene pool causing decreasing variation

2) founders effect - when small number of individuals (founding population) Move to new habitat and start new population. - new population gene pool depend on founding population alleles (less variation)

Inbreeding

• Reproductionof closely related animals over multiple generations

• Deleterious alleles (recesive) make the less fit

Artificial selection

• Humans selectively breeding useful traits

• Advantages - establish certain traits and passed it down. - for disease resistance, strength, calmness, more meat, and endurance

• Disadvantages - decrease genetic diversity. - undesirable (health problems) may appear

5 Evidence of evolution

• Homology structure

• Versigular structure

• DNA evidence

• Embryological development

• Fossile records

Homozygous structure (evolution evidence)

• Similar structure (same origin) but different functions

• Occur when divergent evolution

Vestigial structure (evolution evidence)

• Structure reduced in size and function

• May have been useful before

DNA evidence (evolution evidence)

Species with closer evolutionary relationships show similarity in DNA

Embryological development (evolution evidence)

When embryos of different species develop in similar ways, suggest they have common ancestor

Fossile records (evolution evidence)

• Fossils - preserved remains of organisms

• Gives time scale of how long evolution take

• Shows similarities between extinct animals and animals today

Gradualism

Gradually change over time, rather than sudden large leaps

Punctual equalibrium

• Little to no change (equilibrium) followed by punctual short and rapid change

• Occurs when big change happened in environment - mass extinction event. - migration to new environment. - isolation of a population

Photosynthesis

• Process which plants use sunlight to make energy

• In cloroplast

• Need CO2 and H2O

• Produce glucose and oxygen

• 6CO2 + 6H20 + sunlight—> C6H12O6 + 6O2

Cellular respiration

• Where stored energy is broken to release energy

• In mitochondria

• Need glucose and O2

• produce CO2 and H2O

• C6H12O6 + 6O2 —> 6CO2 + 6H2O + ATP