Biology 30 Diploma

founder effect

genetic drift that results when a small number of individuals separate from their original population and find a new population

gene flow

migration;the movement of alleles from one population to another through the movement of individuals or gametes

sexual dimorphism

striking differences in the physical appearance of males and females not usually applied to behavioural differences between sexes

3 types of population dispersion

1. Clumped

2. Uniform

3. Random

open population

a population in which change in size and density is determined by natality, mortality, immigration, and emmigration

closed population

a population in which change in size is determined by natality and mortality ony

intraspecific competition

an ecological interaction in which individuals of the same species compete for the resources in their habitat

K- selected organism

an organism that is adapted to survive at or near the carrying capacity of it's environment. only a few offspring are produced

r- selected organism

an organism that is addapted to increase population size rapidly

interspecific competition

competition between individuals of different species

interference competition

interspecific competition that involves aggression between individuals of different species who fight over the same resource

exploitative competition

interspecific competition that involves consumption of shared resources by individuals of different species, where consumption by one species may limit the availability for other species

competitive exclusion

the concept that, if resources are limited, no two species can remain in competition for exactly the same niche indefinitely

resource partitioning

avoidance of, o reduction in, competition for similar resources by individuals of different species occupying different non-overlapping ecological niches

succession

the slow, progressive replacement of one community by another during the development of vegetation in any area

primary succession

when a pioneer community inhabits an area not previously occupied by life ( ex. when plants colonize an area where a glacier is retreating)

secondary succession

when small plants begin to grow in an area previously inhabited (ex. plants after a fire in a forest)

Reflex Arc

SIM (sensory, inter, and motor neurons) relay information from the receptors to the effectors. Part of the PNS

function of schwann cells

helps create the myelin sheath; which aids in faster impulse transmission.

how to tell the difference between interneurons and other neurons

interneurons have no schwann cells

CNS vs. PNS

CNS is brain and spinal chord, PNS is nerves outside CNS

function of neurilemma

regeneration of damaged axons

5 parts of transmission impulse

rest, depolarization, repolarization, hyperpolarization, refractory period

depolarization in the neuron

rushing in of Na+ ions

repolarization in the neuron

K- moves out

2 neurotransmitters in the the synapse

acetylcholine- excitory; released by presynaptic membrane, and cholinersterase- inhibitory, to break down acetylcholine

summation in the synaptic cleft

when a neuron is stimulated by 2 or more other neurons

acetylcholine

nuerotransmitter that increases the post-synaptic membranes to sodium

cholinesterase

inactivates acetylcholine

meninges

protective layers around the CNS

frontal lobe

responsible for movement, speech and thought

temporal lobe

responsible for hearing

parietal lobe

sensory (ex. touch, taste, temperature)

occipital lobe

responsible for sight

medulla oblongata

responsible to unconscious activities

hypothalamus

maintains homeostasis; controls the pituitary and the autonomic functions

cerebellum

coordinates motor control

somatic vs autonomic

voluntary processes vs involuntary processes

sympathetic vs. parasympathetic

stress vs. normal

pituitary gland secretions (8)

HGH, TSH, Prolactin, LH, Oxytocin, FSH, ADH, ACTH

Hgh

human growth hormone, from the pituitary; helps in growth

TSH

thyroid- stimulating hormone, from pituitary, stimulates thyroid to release other hormones for metabolism.

Prolactin

stimulates milk production

oxytocin

stimulates milk expulsion and uterine contractions

ADH

antidiuretic hormone, increases the reabsorption of water in kidneys, from pituitary

ACTH

goes to the adrenal cortex, for the release of cortisol, which promotes the use of fats and excess amino acids for energy

aldosterone

salt-retaining hormone; promotes the retention of Na+ by the kidneys which promotes water retention

calcatonin vs. PTH

ca to bones vs. ca to blood

parathyroid secretions (3)

calcatonin , PTH, and thyroxine

insulin vs glucagon

released by pancreas; lower blood sugar vs raise blood sugar

gonads (male vs female)

ovaries- estrogen and progesterone, vs testes- testosterone

type 1 diabetes mellitus

diabetes in which there is no beta cell production of insulin--the patient is dependent on insulin for survival

type 2 diabetes mellitus

diabetes in which the body produces insulin, but the cells don't recognize the insulin

diabetes insipidus

not enough ADH in the body, lower water retention (you'd have to pee more)

adrenal secretions (2)

epinephrine (adrenaline) and norepinephrine (anti-adrenaline)

seminal vessicles

secrete a fluid containing fructose which provide an energy source for sperm

prostate gland

secretes an alkaline fluid that helps protect sperm from the vagina's acidity.

cowper's gland

secretes a mucus just before ejaculation to neutralize any acidic urine that might be present.

epididymus

site of mature sperm storage until discharge.

vas deferens

carries sperm from epididymus to ejaculation duct

seminiferous tubules

place where spermatogenesis takes place.

FSH function (male)

acts on seminiferous tubules to increase sperm production

LH function (male)

acts on interstitial cells to secrete testosterone

hCG

released if a woman is pregnant; it preserves the corpus luteum.

ectoderm

brain, spinal chord, sense organs and outer skin

endoderm

organs

mesoderm

muscles, skeleton, ect.

gastrulation

the process in which a gastrula develops from a blastula by the inward migration of cells

cytokinesis

cell division

mitosis

cell division in which the nucleus divides into nuclei containing the same number of chromosomes

events in mitotic prophase

centrioles move to poles; spindles form

nuclear membrane faddes

chromosomes shorten and thicken

events in mitotic metaphase

chromosomes meet in the middle

events in mitotic anaphase

chromatids separate and begin to move to opposite poles

telophase

nuclear membranes reform

haploid vs diploid

n (gamete) vs 2n (somatic)

autosomes/somatic cells

body cells; they have a full set of chromosomes and are not gender determining.

zygote

the fertilized egg

meiosis

process of creating haploid cells

incomplete dominance

when 2 genes of a pair are equally dominant; so a new phenotype is created.

codominance

a condition in which both alleles for a gene are fully expressed

transcription

(genetics) the organic process whereby the DNA sequence in a gene is copied into mRNA

translation

(genetics) the process whereby genetic information coded in messenger RNA directs the formation of a specific protein at a ribosome in the cytoplasm

centromere

the structure that holds chormatids together

sister chromatids

identical copies of a replicated chromosome connected by a central

centriole

attachment site for for spindle fibre

interphase

cell growth, repair and basic functions occur

g1 phase

growth and development occur

s phase follows

s phase

dna replication

g2 phase

when organelles needed in cell division are made

identical twins

originated form single egg cell after fertilization

fraternal twins

originate from two different eggs and sperm

trisomy

extra chromosome 47

monosomy

missing chromosome 45

haploid

n=23

diploid

2n=46

homologous chromosome

identically paired chromosomes

synapsis

the pairing of homologous chromosomes

prophase I and II

chromosomes pair up in synapsis and crossing over. attaches to spindle

metaphase I and II

chromosomes line up in the middle

anaphase I

chromosome separates from its pair and move to ends