DAT Biology Section -

Key Decomposers

fungi & bacteria, mites/springtails, millipedes & earthworms

Biomes

biotic units that are classified by predominant plant types; at least 8 major terrestrial biomes

Tropical Rainforest - Location

rain forests restricted to equatorial zone; cover less than 2% of Earth’s surface

Tropical Rainforest - Climate

warm and very wet year-round

Tropical Rainforest

tall broadleaf evergreen trees, dense vegetation; high diversity of plant and animal life

Tropical Rainforest - Species

high diversity of plant and animal life; home to about 50% of all terrestrial species; most diverse and productive terrestrial ecosystems on our planet

Tropical Rainforest - Plants

evergreen trees, climbing vine, epiphytes, strangler figs; many trees grow buttresses that function as prop roots in shallow soil that offers poor anchorage; ground cover → understory → lower canopy → upper canopy → emergent canopy

Tropical Savanna - Climate & Location

warm, semiarid regions with seasonal rainfall; wet and dry seasons

Tropical Savanna

grasses with scattered drought-resistant shrubs and trees; fire-maintained ecosystem

Tropical Savanna - Animals

large diversity of herbivores that graze or browse on vegetation; supports large number of insects, carnivores (lions, hyenas), scavengers (vultures)

Tropical Savanna - Plants

have 2-layer vertical structure (grasses and trees/shrubs); trees create small microenvironments (rescue hotspots)

Tropical Savanna - Microenvironments

“rescue hotspots;” support more biodiversity than surrounding grassland, soil is richer (more leaf litter and nutrients), shaded ground is cooler, soil holds more moisture

Temperature Deciduous Forest - Climate & Location

Moderate temp + rainfall, four seasons

Temperature Deciduous Forest - Plants

broadleaf deciduous trees dominate; seasonal changes affect plant growth; usually 4 vertical layers/strata: floor → shrubs → understory → canopy

Temperature Deciduous Forest - Nutrients

rich soils and understory of shrubs, ferns, and wildflowers

Temperature Deciduous Forest - Animals

seasonal changes affect animal behavior; diversity of animal life is associated with vertical stratification and plant growth forms; highest diversity occurs on and just below ground layer

Temperate Grasslands - Climate & Location

moderate temp, low precipitation; often experience drought as they occur in regions where annual precipitation is reduced as air masses more inland; original extent of shortgrass, mixed-grass, and tallgrass prairies in North America before arrival of Europeans

Temperate Grasslands - Animals

dominated by herbivorous species; insects, large grazers, burrowing mammals

Temperate Grasslands - Grazing

grasslands evolved under selective pressures of grazing; stimulates primary production; moderate grazing can stimulate grass growth, but heavy grazing reduces productivity

Temperate Grasslands - Plants

3 strata in grassland: herbaceous plants, ground cover, and belowground root layer (can make up more than half of plant biomass and extends deep into soil

Shrublands - Climate & Location

hot, dry summers + cool, wet winters

Shrublands - Plants

shrubs and dwarf trees dominate; plants are adapted to fire and low nutrients; sclerophyllous plants are characteristic of shrublands

Shrublands - Sclerophyllous Plants

have thick, tough, and leathery leaves with waxy coating that helps reduce water loss

Shrublands - Nutrients

soils are generally deficient in nutrients

Shrublands - Animals

drought-tolerant mammals, birds, and reptiles that use shrubs for food and shelter

Deserts - Climate & Location

very low precipitation, can be hot (Sahara) or cold (Gobi); high evaporation rates → extremely dry conditions

Hot Deserts - Plants

plants have adaptations to very arid climate; hot deserts range from those lacking vegetation to ones with some combination of herbs, dwarf shrubs, and succulents

Hot Deserts - Animals

animals have adaptations to very arid climate; animals avoid heat and conserve water; ex: Kangaroo rat gets water from seeds, never drinks

Cold Deserts - Plants

plants have adaptations to very arid climate; cold deserts range from vegetation dominated by sagebush, shadscale, woody shrubs and grasses adapted to cold, dry conditions

Cold Deserts - Animals

animals have adaptations to very arid climate; animals conserve heat and survive long dormant seasons; ex: Bighorn sheep has thick, insulated coat, can go long periods without drinking

Boreal Forest (Taiga) - Climate & Location

cold, long winters, short summers, about 6-10 wks warm enough to photosynthesize; primarily occupies formerly glaciated land; as temp decreases and growing seasons shorten toward Arctic, trees become fewer, shorter, and more widely spaced

Boreal Forest (Taiga) - Plants

dominated by evergreen conifers, needles prevent water loss, conical shape sheds snow; as temp decreases and growing seasons shorten toward Arctic, trees become fewer, shorter, and more widely spaced

Boreal Forest (Taiga) - Animals

unique animal community; herbivores include caribou, moose, snowshoe hare, red squirrels, and porcupine; predators include wolf, lynx, pine martin, and owls

Tundra - Climate & Location

very cold, very low precipitation

Tundra - Plants

dominated by small shrubs, grasses, herbs, mosses, and lichens; vegetation structure is simple; few species and slow growth; only species that can withstand constant soil disturbance, buffeting by wind, and abrasion by wind-carried particles of soil and ice can survive; arctic plants propagate almost entirely by vegetative means

Tundra - Animals

low animal diversity, dominant vertebrates are herbivores

What monosaccharides compose lactose?

Glucose and galactose

What monosaccharides compose maltose?

Glucose and glucose

What monosaccharides compose sucrose?

Glucose and fructose

Porphyrins

In assossiation with lipids, composed of 4 pyrrole rings with a metal atom in the center (e.g. haemoglobin -iron- and chlorophyll -magnesium-)

Disulfide bonds are created by

covalent bonding between 2 R-groups of cysteine amino acids; unique to proteins in organic molecules

kinase

transfers a phosphate from an ATP to a molecule

phosphatease

catalyzes the removal of a phosphate from a molecule

transferase

transfer functional groups to another molecule

hydrolase

category of enzymes that breakdown molecules using water; lipase, peptidase, nuclease, and amylase break down macro molecules

3 high yield petidases:

trypsin, chymotrypsin, and pepsin

synthase

catalyze synthesis of new compounds

ligase

seals together bonds

endonuclease

cuts DNA in the middle of the chain

exonuclease

cuts nucleotides one at a time from the ends of a DNA chain, needs a free 3’ or 5’ end

Phosphofructokinase

rate-limiting enzyme for glycolysis

Melatonin

• Released by pineal gland

• amino acid derivative

• regulates circadian rhythm (sleep cycle)

Oxytocin

• synthesized by hypothalamus and stored in posterior pituitary gland

• peptide hormone

• stims uterine contractions during labor and milk ejection during lactation

• stims emotional bonding and reduces stress; “love hormone”

Vasopressin (ADH)

• antidiuretic hormone

• synthesized by hypothalamus and stored in posterior pituitary gland

• peptide hormone

• increases water absorption in kidneys to maintain blood/water levels

GnRH

• Gonadotropin-releasing hormone

• from hypothalamus, sent to anterior pituitary gland

• peptide hormone

• stimulates APG to release FSH and LH

FSH

• follicle-stimulating hormone

• made in anterior pituitary gland

• peptide hormone

• stimulates spermatogenesis in males and estrogen release in females

LH

• luteinizing hormone

• made in anterior pituitary gland

• peptide hormone

• stimulates testosterone release in males and progesterone release in females, triggers ovulation in females, and forms the corpus luteum (which produces progesterone to support early pregnancy)

TSH

• thyroid-stimulating hormone

• made in anterior pituitary gland

• peptide hormone

• stimulates thyroid gland to release T3 and T4

ACTH

• adrenocorticotropic hormone

• made in anterior pituitary gland

• peptide hormone

• stimulates adrenal cortex (in kidney) to release glucocorticoids

Prolactin

• made in anterior pituitary gland

• peptide hormone

• stimulates mammary gland cells to produce milk

GH

• growth hormone

• made in anterior pituitary gland

• peptide hormone

• stimulates bone and muscle growth and various metabolic functions

MSH

• melanocyte-stimulating hormone

• made in anterior pituitary gland

• peptide hormone

• stimulates melanocytes to produce melanin (protects against UV radiation)

T3 and T4

• thyroid hormones

• increases metabolic rate, requires iodine for synthesis

Calcitonin

• secreted by thyroid gland

• peptide hormone

• lowers blood calcium levels by building up bone, halts osteoclasts and encourages osteoblasts

PTH

• secreted by parathyroid hormone

• peptide hormone

• raises blood calcium levels by breaking down bone, halts osteoblasts, encourages osteoclasts

Thymosin

• secreted by thymus

• peptide hormone

• stimulates T-lymphocyte development

Epinephrine/norepinephrine

• secreted by adrenal medulla (inside adrenal gland on kidneys)

• catecholamines

• raises blood glucose level, increases metabolic activities, alters blood flow to prioritize fight or flight organs

Glucocorticoids (cortisol)

• secreted by adrenal cortex (on kidneys)

• steroid hormone

• raises blood glucose level

Mineralocorticoids (aldosterone)

• secreted by adrenal cortex (on kidneys)

• steroid hormone

• promotes reabsorption of Na+ in kidneys; increases water retention and raises blood pressure

Cortical Androgens

• secreted by adrenal cortex (on kidneys)

• steroid hormone

• low amounts of testosterone and estrogen

Insulin

• secreted by pancreas

• peptide hormone

• lowers blood glucose level and stimulates glucose storage

Glucagon

• secreted by pancreas

• peptide hormone

• raises blood glucose level and stimulates glucose production

Somatostatin

• secreted by pancreas

• peptide hormone

• inhibits release of insulin, glucagon, and GI hormones; decreases gastric motility

Estrogen

• secreted by ovaries

• steroid hormone

• regulates menstrual cycle; promotes development and maintenance of female secondary sex characteristics

Progesterone

• secreted by ovaries

• steroid hormone

• maintains early pregnancy and regulates uterine lining thickness

Testosterone

• secreted by testes

• steroid hormone

• supports sperm formation; increases muscle mass; promotes development and maintenance of male secondary sex characteristics

p53 gene

suppresses tumors by preventing cells with damaged DNA from dividing

Start Codon

AUG

Stop codons

UAG, UAA, UGA

Never Let Monkeys Eat Bananas

Ranking for WBC count from highest to lowest:

Neutrophils > Lymphocytes > Monocytes > Eosinophils > Basophils

IgG

most abundant class of antibody, can cross the placenta

IgA

class of antibody found in breast milk and mucosa

IgM

the first class of antibodies produced after initial exposure to antigens

IgE

class of antibody related to allergies

IgD

class of antibody where function is not fully understood

FLAT PiG

Anterior pituitary hormones:

FSH, LH, ACTH, TSH, Prolactin, Growth hormone (HGH)

Deuterostome cleavage:

indeterminate and radial

Oparin and Haldane’s Hypothesis

Organic molecules formed from inorganic molecules interacting with lightning & UV radiation; most likely caused by tide pools heating up and water evaporating to expose/condense the inorganic molecules

Miller and Urey’s Experiment

confirmed amino acids could be formed from UV and lightning interacting with inorganic molecules similar to early Earth’s atmosphere

Georges Cuvier

Proposed catastrophism: Earth’s history is shaped by major geologic catastrophic events that happened in a short period of time (meteors, super volcanoes, etc) leading to mass extinctions and impacting ecosystems/evolution drastically

Uniformitarianism/Gradualism

U: changes to earth happened via small-scale processes over a long period of time (such as the movement of tectonic plates)

G: evolution of organisms happens via small scale processes (genetic changes) over a long period of time

Inheritance of Acquired Characteristics

Lamarck’s Theory: used traits are passed to offspring and disused traits are not passed to offspring + natural transformation of species

Ex: you build muscle and your children are muscular; you don’t use certain teeth, and your children don’t have those teeth

Natural Transformation of Species

Part of Lamarck’s Inheritance of Acquired Characteristics Theory; proposed that offspring become more complex than their preceding generation and that organisms do not become extinct or split off into more species

Survival of the Fittest

• Natural Selection - Darwin + Wallace:

  • pressure of environment increases fitness by selecting for advantageous traits that are passed to offspring

• Decent with Modification: variation is within populations and traits get selected to eventually produce modified offspring, many changes over a long period of time can give rise to evolved populations or new species

Synthetic Theory of Evolution

• modern understanding of Darwin’s theory

• genetic mutations produce variations

• genes are passed to future generations, not phenotypes

Stabilizing Selection

Narrow bell curve, the average version of a trait is most advantageous

Directional Selection

The bell curve has shifted towards one of the extremes

Disruptive Selection

The bell curve has split into 2 curves that shifted towards the 2 extremes, average trait is not advantageous

Sexual Selection

differential mating of males and females can cause specific traits to be selected more frequently; leads to sexual dimorphism

ex: large antlers on male deer and healthy coats on female deer

Intrasexual Selection

selection within the same sex via competition of mating opportunities; usually male behavior

ex: male deer fighting each other