Chromosome

thread-like structure located inside the nucleus of the cell

made of protein and a single molecule of DNA

23 pairs or 46 chromosomes in total

[mutants- those who experience complications]

DNA [Deoxyribonucleic acid]

molecule that carries genetic information

Gene is a cut segment of the DNA

Genes

the basic physical and functional unit of heredity

used to determine some characteristics of the offspring

Heredity

passing on traits from parents to offspring

asexual or sexual reproduction

Heredity -traits - sperm and egg- nucleus- chromosomes - DNA- gene- alleles-(dominant and recessive)

Genetic variations

describe the difference in DNA among individuals

Gregor Mendel

“Father of genetics”

initiated the study of genetics through his experimentation on pea plants and proposed 3 laws of inheritance

why pea plants?

1. multiple variation traits

2. generation is short

3. mating is easy to control

Mendel’s 3 important conclusions

1. inheritance of each trait is determined by “units” or “factors” that are passed on to descendants unchanged

2. an individual inherits one such unit from each parent for each trait

3. a trait may not show up in an individual but can still be passed on to the next generation

Alleles

different variations of genes

dominant or recessive

Dominant

show their effect if the individual only has one copy of the allele (capital letters)

Recessive

only show their effect if the individual has two copies of the allele (lowercase)

Allele combinations

Homozygous Dominant (XX)

Heterozygous (Xx)

Homozygous Recessive (xx)

Phenotype

physical characteristics

Genotype

Genetic make up

Laws of Mendel

1. law of segregation

   A person who has 2 letters for a gene can only pass one allele or the other to each offspring

2. Law of independent assortment

   two or more traits are inherited separately from each other; they can’t always occur together

3. Law of dominance

   one dominant allele will take charge over a recessive allele and “mark it

   the only way a recessive allele can be seen is if an individual possesses two copies of the recessive allele

Non-mendelian

any inheritance pattern that don’t follow one or more laws of Mendelian genetics

incomplete dominance (no dominant, no recessive)

blending- the appearance of a certain trait can be a mixture of contrasting characteristics of the parents

the combination of the two traits results in an intermediate expression of both traits that don’t resemble the traits of the parents

law of dominance doesn’t apply

ex. Japanese four o’clock flower [white x red = pink]

codominance

both alleles in heterozygous are fully expressed at the same time

ex. pigs [white x black = white and black]

sex-linked traits

controlled by the genes located on the sex chromosomes

ex. hemophilia and colorblindness

red- green blindness

rarely occurs in females and approx. 8% of males

genes associated with red-green color vision are located in the x-chromosomes

hemophilia

inherited bleeding disorder in which the blood does not clot properly

multiple alleles

can be mendelian and non-mendelian (codominance and dominance)

traits that are controlled by more than one gene

ex. blood type

Species

a group of similar organisms that are able to breed and produce viable offspring under natural condition

Taxonomy of living things

domain(eukarya)

kingdom(Animalia)

phylum(chorelata)

class(Mammalia)

order(primates)

family (Hominidae)

genus(homo)

species (sapiens)

ex. canis familiarise [dogs], heliconius timareta timareta [butterfly], caladiums [plant],

biodiversity

variety of life forms that thrive on earth

describes the differences and relationships within various ecosystems including non-living things and their non-living environments

species-population-community-ecosystem (living or non-living)- biodiversity

measure biodiversity

1. species richness

   number of species in a particular place, most common biodiversity index

2. species evenness (maintain balance)

   extent to which individuals redistributed evenly among species

   gives information about the relative quantities or populations of individuals belonging to different species

drop in species richness or evenness- endangered/endemic- extinction and loss of biodiversity

endemic

specific area where a species can be found exclusively

extinction and loss of biodiversity

occurs when species do not have adaption that enables them to survive environmental changes

a species is extinct when no members remain alive anywhere in the world

causes of extinction

1. natural causes

coextinction

the loss of one species leads to the loss of another, a chain of extinction

uncontrolled predation

exotic and non-active species are introduced to new habitats, if they don’t have natural enemies in their new habitat, then their prey eventually becomes extinct

mass extinction

sharp decrease in the number of species on earth in a short period of time

climate heating and cooling

many species are not used to severe weather conditions and long seasons or the changing chemical makeup of their surroundings

2. anthropogenic causes

habitat destruction, degradation, and fragmentation

habitat serves as a home for countless animal and plant species

these are destroyed due to industrialization and urbanization

invasive species

humans sometimes bring new species to new habitats where they become invasive,

not invasive if it doesn’t harm the community of others

ex. competition for snail food between Chinese turtles and native turtles

population

the demands of the increasing population lead to consuming more of their needs causing the exploration of species

pollution

the destruction and poisoning of the air environment have a disastrous effect on other species

climate change

much of the products of industrialization cause climatic changes in the temperature

[heat enters the earth the blanket [2 types 1. carbon dioxide, 2. ozone layer]

1. ozone layer - blocks the heat, and harmful rays and prevents them from entering the earth

2. carbon dioxide- traps the heat inside the earth causing global warming

over-exploitation

harvesting species in the wild at rates faster than natural populations can recover

a third of the world's endangered vertebrates are threatened by over-exploitation

extinction

loss of an entire species anywhere in the world

generally caused by natural and biological factors that affect the organisms and their habitats

vulnerable (v) high risk of extinction in the wild

endangered (en) very high risk of extinction in the wild

critically endangered (cr) extremely high risk of extinction in the wild

ex. tamaraw, dugong, visayan warty pig, ph crocodile, ph eagle, mindoro hombil

Ordovician-Silurian (change in temp, climatic heating or cooling, coextinction) [fish]

“age of fish”

organisms such as corals and shelled brachiopods filled the world’s shallow water but not land

the climatic shift changed the sea temp. (turned into ice)

at the end of this period, the rapid onset of mass glaciation covered Gondwana (southern supercontinent)

the glaciation locked away high percentages of the world’s water and dramatically lowered global sea levels (destroyed food chains decreased reproductive success and striped vital habitats)

late Devonian (oxygen depletion due to algae) [fish to amphibians]

caused by vascular plants such as trees and flowers

plants evolved roots and transformed the land turning rock and rubble into soil

nutrient soil ran into the world’s oceans causing algae to bloom

algae created a giant “dead zone” where algae strips oxygen from the water suffocating marine life

and wreaking havoc on the marine food chain, (species unable to adapt to decreased oxygen levels and lack of food)

Permian-Triassic (volcanic eruption, climate heating or cooling) [fish- amphibians- reptiles]

“age of reptiles”

“great dying” -largest hit on earth wipes out 90% of species

siberia’s volcanoes erupted and released a large carbon dioxide causing greenhouse effects that hearted the planet causing weather patterns to shift, sea levels to rise, and acid rain to fall on land

the carbon dioxide dissolves into the water (poisoning marine life and depriving them of oxygen-rich oxygen)

Triassic-Jurassic (volcanic eruption, climate heating or cooling)

volcanoes released enormous amounts of carbon dioxide causing climate change

global temp. increased ice melted and the sea level rose and acidified

this killed flying pterosaurs and large prehistoric crocodiles

cretaceous-paleogene (asteroid impact, climate heating or cooling)

“the day the dinosaurs died”

“K-T” extinction

Geologists call it “K-Pg” extinction because the letter C is shorthand for a previous geological period called Cambrian

K from “K-T” is from a German word “Kreide” meaning cretaceous

Stomata

tiny openings present on the epidermis of leaves

Chloroplast

organelle within the cells of plants and certain algae that is the site for photosynthesis

Chlorophyll

pigment that gives plants a green color

Glucose

known as sugar and the end product of photosynthesis

Thylakoid

pouch-like sacs that are bound to a membrane in the chloroplast

Adenosine triphosphate (ATP)

Source of energy for use and storage at the cellular level

Nicotinamide adenine dinucleotide phosphate (NADPH)

essential electron donor in all organisms

photosynthesis

a chemical process that involves the conversion of inorganic matter into organic matter through energy provided by sunlight

importance:

a vital energy source (photosynthesis converts sunlight into chemical energy nourishing plants and initiating food webs on earth )

oxygen production (photosynthetic organisms release oxygen as a byproduct, sustaining the respiration of most living beings and enriching the atmosphere with this gas)

climate regulation: (photosynthesis absorbs carbon dioxide aiding in climate change control and maintaining the balance of the greenhouse effect)

Light-dependent reaction or photochemical reaction

occurs on the Granum [Thylakoid membranes]

requires light

2 absorbing molecules: photosystem 1 and photosystem 2

expected products: oxygen gas (byproduct), NADPH, and ATP

input or raw materials: water and light

Light-independent reaction or Calvin cycle

occurs in the stroma

no presence of photosystems

doesn’t require light

has no byproduct

raw materials: NADPH, ATP CO2

CO2 capture: an enzyme called RuBisCO fixes CO2 into organic compounds

Sugar information: the resulting molecules convert into sugar, utilizing ATP and NADPH from the light-dependent phase

RuBisCO regeneration: molecules enabling CO2 capture to regenerate, ensuring cycle continuity

readying for new cycle: creating sugars and regenerating molecules for CO2 Fixation

expected product: glucose (C6H12O6) and oxygen

similarities: stages of photosynthesis, and happens in the chloroplast

photosynthetic organisms:

microalgae (chlorella vulgaris), plants (the primary terrestrial photosynthetic organisms sustaining life and regulating the climate), macroalgae (kelp), bacteria (chloroflexi)

fluorescence

light re-emitted by chlorophyll molecules during the return from excited to non-excited states

abundant fluorescence indicates active photosynthesis in a well-functioning plant.