Biology 1010 Final (New Content Only)

Oogenesis

Embryonic females possess oogonia which undergo mitosis, produces primary oocytes. Primary oocytes enter meiosis I, but body arrests Meiosis I, and resumes with the first menstrual cycle.

Follicle

Primary oocyte and the cell layer around it

Follicle-stimulating Hormone (FSH)

Levels increase in the blood at the start of the menstrual cycle, stimulates follicles to grow and race.

Oocyte

Female germ cell that splits into a large secondary oocyte and tiny polar body, then halts in metaphase II.Travels down the oviduct to the uterus

Secondary oocyte

Gets nearly all the cytoplasm, = haploid number of chromosomes. Starts meiosis II

Polar body

Gets almost none of the cytoplasm, small haploid cell that doesn’t have the ability to become a zygote

Menstrual Cycle and Cyclic Changes in the Ovary

Estrogens stimulate growth of endometrium, An oocyte matures and escapes from an ovary

Corpus luteum

Forms from ruptured follicle, secretes progesterone and estrogen. Self destructs in last days of cycle if no egg fertilizes

LH

Hormone that triggers ovulation and formation of the corpus luteum

Blood flowing out of the vagina

Caused by corpus luteum breaking down, progesterone and estrogen levels crashing and endometrium breaking down

Erection

Caused by arousal in males, leads to blood flow in penis which fills spongy tissue

Fertilization

May occur if sperm arrives in the oviducts shortly before or after ovulation. Muscle contractions move sperm through the vagina into the upper oviduct. One sperm fuses with the oocyte.

Zygote

Penetration of the sperm induces the oocyte to finish meiosis II, when the sperm and egg fuse it creates this

Birth Control Options

Condoms, abstinence, vasectomy, IUD, Morning after pills etc…

STDs

Infect 1 out of 4 people who engage in sexual intercourse

Chorionic gonadotropin

Stimulates corpus luteum to produce progesterone, hormone that is detected in pregnancy test

Oxytocin

Near the end of the pregnancy, hormone that causes contraction of the uterus. Also released when newborn suckles on breast, triggers contractions that force milk into the milk duct.

Placenta

After 3rd month of pregnancy, chorionic gonadotropin falters, this starts to produce progesterone

Lactation

Occurs in mammary glands in the breast. Milk produced by removing calcium, sugar, vitamins and water from the blood

Galactorrhea

Allows men to lactate with high prolactin levels

Prolactin

Synthesis of enzymes required for milk production

Colustrum

Produced in the first 3 post pregnancy days, clear yellow fluid that contains antibodies

Dendrites

Extensions where neurons receive information

Axons

Extensions that carry signals away from the neurons

Action potential

Reversal in charge across a neuron’s plasma membrane, how neurons accept and pass signals

Chemical synapse (synaptic cleft)

Narrow cleft between the output zone of a neuron and input zone of adjacent cell

Neurotransmitters

Signaling molecules that diffuse across synaptic clefts

Nerves

Long axons of sensory neurons (detect stimuli) or motor neurons (react)

Reflexes

Automatic movements made in response to stimuli

Sensory neurons

Connected to motor neurons in the spinal cord, detect stimuli

Phineas Gage

Man with rod launched into his skull, changed his personality but he lived after for a while

Central nervous system

Contains the spinal cord and brain

Brain

Control center of the nervous system

Spinal chord

Expressway for signals between the peripheral nervous system and the brain, where sensory and motor neurons connect

Peripheral nervous system

Nerves which thread through the rest of the body

Somatic nerves

Control skeletal muscles (reflex arcs)

Autonomic nerves

Control smooth muscle, cardiac muscle, and glands

Tympanic membrane

Transmits movements (because of soundwaves) to ossicles (3 ear bones)

Malleus, Incus, and Stapes

These ossicles transmit movement to the oval window

Cochlea

Contains fluid, when the oval window moves it moves the fluid within the cochlea

Organ of Corti

Detects movements of fluid within the cochlea and transmits this information to the brain via the auditory nerve

Cornea

Clear covering of the eye

Iris

Muscle that regulates the amount of light that passes into the eye, the colored part

Pupil

Entrance for light

Lens

Focuses images on to the retina

Retina

Thin layer in the back of the eye. Contains two types of photoreceptors, cones and rods

Cones

Photoreceptor used for color and detailed vision, located in area called fovea centralis

Rods

Scattered throughout the retina, photoreceptor for low-light vision

Optic nerve

Carries sensory input from the eyes to the brain

Human population

Root directly or indirectly of many environmental problems. Follows exponential growth curve. Was 2.5 billion in 1950 now 8+ billion. We are now increasing at a decreasing percentage rate.

Logistic growth curve

Has a carrying capacity and trails off

Species

Organisms that can interbreed with one another and produce offspring that can reproduce

Biodiversity

Variety of different species, genetic variability and the variety of ecosystems within one area.

Threats to biodiversity

Introduction of exotic species, commercial harvest, habitat destruction

Ecosystem

Made up of the organisms and the non-living environment within a defined area

Pacific yew

Produces taxol, used to treat ovarion, breast and lung cancer

Malayan pit viper

Produces the chemical ancord, used to prevent blood clots in heart attack and stroke victims

Epipedobates tricolor

Produces epibartine, more effective than morphone at relieving pain and not addictive

Alabama Biodiversity

Ranks 5th in biodiversity,#1 in aquatic biodiversity, more species of mussels, snails, crawfish etc.