scsc7211’s Version of Alan’s DAT Biology Notes
Chapter 1: Basis of Life (1& 2 in Cliff's)
Chapter 2: Reproduction (5-cell division &12-human reproduction in Cliff's)
Chapter 3: Genetics (6&7 in Cliff's)
Chapter 4: Embryology (12 in Cliff's)
Chapter 5: Vascular System in Plants and Animals (10&11 in Cliff's)
Chapter 6: Endocrinology (11 in Cliff's)
Chapter 7: Neuroscience (11 in Cliff's)
Chapter 8: Respiration (3 in Cliff's)
Chapter 9: Autotrophic Nutrition (4 in Cliff's)
Chapter 10: Muscles and Locomotion (11 in Cliff's)
Chapter 11: Digestion (11 in Cliff's)
Chapter 12: Excretion (11 in Cliff's)
Chapter 12.5: Integumentary
Chapter 13: Animal Behavior (13 in Cliff's)
Chapter 14: Ecology (14 in Cliff's)
Chapter 15: Classification (9 in Cliff's)
Chapter 16: Evolution (8 in Cliff's)
Chapter 1 – Basis of Life
Ingestion – acquisition of food
Assimilation – building of new tissues from digested food
Monosaccharide – (carb) single sugar subunit
Disaccharide – glycosidic linkage
Ex:glucose+fructose = sucrose, glucose+galactose=lactose, glucose+glucose=maltose
Polysaccharide – (carb) polymer, insoluble in water;
ex: glycogen (energy storage in animals), starch (energy storage in plants), Cellulose (polymer of beta-glucose/structural), Chitin (like cellulose, but glucose has a nitrogen/structural molecular in fungi and exoskeleton of insects, arthropods, and mollusks)
Lipids – (2:1 H/O ratio) 3 FA bonded to glycerol=triglyceride; chief means of food storage
· Major component of adipose tissue
· Steroids (estradiol, testosterone, cholesterol), waxes, carotenoids, porphyrins
Proteins - polymers of AA joined by peptide bond / 1* = AA sequence, 2* = folding (alpha beta)
· Hormones (ACTH & insulin), Enzymes, structural pro (collagen), transport (hemoglobin), antibodies
Enzymes – lower activation E & inc. rate of rxn / do not affect overall E
· Higher temp = inc enzyme action / optimal pH = 7.2 (except pepsin & pancreas)
· Competitive inhibitors compete w/ substrate for binding at ACTIVE site; can be overcome by adding more substrate; Vmax not affected
· Noncompetitive inhibitors bind at allosteric site; diminishes Vmax
· Holoenzyme: union of cofactor and apoenzyme
· Cooperativity: enzyme more receptive to additional substrate after one substrate molecule attaches to an active site
o Ex: Hemoglobin- binding capacity to additional oxygen increases after first oxygen binds to active site
Prokaryotes – bacteria, cell wall, NO nucleus (instead nucleoid regionà”naked DNA”), NO memb-bound organelles, ribosomes smaller and no mem (70S, w/ 50S and 30S VS 80S w/60S 40S in Euk.), mesosomes (invaginations of membrane), flagella of prokaryotes not constructed of microtubules
Eukaryotes – cell wall in fungi & plants, nucleus, membrane-bound organelles
- Nucleus contains nucleolus(sometimes more than one): concentrations of DNA in the process of manufacturing components of ribosomes
- Nucleolus: concentrations of DNA in the process of manufacturing components of ribosomes
- Chromatin: the normal (non-replicating) form of DNA, spread out in a threadlike matrix
Endomembrane system: different membranes suspended in the cytoplasm
- Includes (nuclear envelope, E.R., Golgi, lysosomes, vacuoles, vesicles, peroxisomes, and cell membrane
- Does NOT include (mitochondria and chloroplasts)
Endoplasmic reticulum: extension of nuclear envelope – all of the proteins that will exit the cell are originally delivered to the ER, then to the Golgi for export
Rough ER (ribosomes present)- creates glycoproteins by attaching polysaccharides to polypeptides
Smooth ER (ribosomes absent)- synthesis of lipids and hormones (often for export)/ in liver, involved in breakdown of toxins, drugs, and toxic byproducts of cellular rxns
Golgi apparatus: modify (glycosylation) and package proteins and lipids into vesicles (spherical sacs that bud out from the Golgi and often merge with the cellular membrane so contents are released to outside of cell)
Centrioles – microtubule involved in spindle organization during cell division/ NO membrane
Centromere – near middle of eukaryotic chromosomes where spindle fibers attach
Lysosome – membrane bound, involved in ingestion / hydrolytic enzymes. Low pH à so inactive in cytosol. NOT in plant cells.
Peroxisomes- break down H2O2, fatty acids, amino acids. Common in liver and kidney cells. In plant cells, modify by-products of photorespiration. In germinating seeds, glyoxysomes break down stored fatty acids
Mitochondria – exhibit maternal inheritance – carry out aerobic respiration
Chloroplasts- Carry out photosynthesis – incorporate energy from sunlight into carbohydrates
Microtubules < intermediate filaments < microfilaments: three comprise cytoskeleton
· Microtubules- made of tubulin, support for cellular activities, found in spindle apparatus, and flagella
· Int. filaments- maintain shape of cell
· Microfilaments- made of actin, involved in motility, found in muscle cells and phagocytes
Flagella and cilia: 9+2 array – nine pairs of microtubules surrounding pair of microtubules
Centrioles and Basal body: centrioles- give rise to microtubules for spindle. Basal body- at base of flagella and cilium and appear to organize their development
· Both made up of 9 triplets of microtubules arranged in circle
Central vacuole- occupy most of interior of certain plants. Exert turgor (pressure) on cell walls to maintain rigidity. Store nutrients and fxns otherwise carried out by lysosomes in animal cells
Cell wall: found in plants, fungi, protists, and bacteria. Plants=cellulose, fungi=chitin (hydroxyl group of cellulose replaced by nitrogen)
Extracellular matrix: area between adjacent cells – most common protein in region is collagen
Anchoring Junction: protein attachments between animal cells
· Desmosomes = “spot welds”; attach cells together and give cells mechanical strength- keratin (ex. skin cells)
Tight junctions = completely seal the spaces b/w cells and prevent cell leakage between animal cells (ex. intestinal cells)
Communicating junctions:
· Gap junctions = allow animal cells to exchange ions and small molecules without cytoplasmic mixing and for molecular communication/ made up of connexins.
- Plasmodesmata: narrow channels between plant cells. Narrow tube of ER, called desmotubule, surrounded by cytoplasm and plasma membrane, passes through channel
Endosymbiotic Theory – mitochondria and chloroplasts originated as independent unicellular organisms living in symbiosis with larger cells
Fluid Mosaic – lipids and proteins are free to move back and forth fluidly; diffuse laterally
· Integral Membrane are embedded in membrane by hydrophobic interactions
o Transmembrane: integral that spans the entire membrane
· Peripheral are stuck to integral membrane proteins by H bonding
Cell surface Receptors – type of integral membrane protein; three types: ligand-gated (open ion channel), catalytic, and G-protein
G-Protein – use secondary messengers such as cAMP which amplify signal
Glycocalyx- carbohydrate coat that covers outer face of cell wall of some bacteria and outer face of plasma membrane of some animal cells (adhesive capabilities, barrier to infection, or marker for cell recognition)
Bulk flow: collective movement of substances in same direction in response to pressure (ex. Blood moving through a blood vessel)
Passive transport: (1) Simple diffusion: high to low (2) Osmosis: diffusion of water across membrane (3): Dialysis: diffusion of solutes (4) Plasmolysis: movement of water out of cell, resulting in collapse (5): Facilitated diffusion: solutes or water through channel protein (6) Countercurrent exchg: diffusion of substances between two regions in which substances are moving by bulk flow in opposite directions
Plant v animal cell:
-Plant cells have/animal cells lack: cell walls, chloroplasts, and central vacuoles
-Animal cells have/plant cells lack: lysosomes, centrioles, and cholesterol
Chapter 2 – Reproduction
Marine reproduction strategies:
Oviparous – internal fertilization; lay eggs “egg birth”
Viviparous – internal fertilization; “live birth”
Ovoviviparous – internal fertilization; egg develops inside mother “egg live birth”
CELL DIVISION – nuclear division followed by cytokinesis
Cell cycle:
S phase – replicate genome (create chromatids)
G1 & G2 phase – gap phases
Mitosis – 2N=>2N, occurs in all dividing cells; 10% of cell cycle
1. Interphase (90% of time) – replication of genetic material resulting in sister chromatids
2. Prophase – chromatids condense into xsomes; nuclear envelope breaks down; microtubule spindles form and attach to kinetochore of centromere
3. Metaphase – chromosomes align across metaphase plate
4. Anaphase – sister chromatids separate; shortest phase
5. Telophase – new nuclear membranes form (cleavage furrow forms); spindles disappear, and chromosomes disperse into chromatin
6. Cytokinesis- in animal cells, a cleavage furrow forms and membrane is pinched in two by microfilaments
a. PLANTS: vesicles from Golgi body migrate to central plane and fuse to form a cell plate, followed by cell wall development; also, plants lack centrioles, and spindle is synthesized by MTOCs that are not visible
Meiosis – occurs in sex cells, homologous chromosomes pair at meta plate (tetrads), crossing over can occur, 2N=>N
- First Meiotic Division produces 2 daughter cells w/ N chromosomes w/ sister chrom
1. Prophase I – chromatids of homologous chromosomes pair up and exchange genetic material (crossing over)- called synapsis. When tetrads (groups of four chromatids line up and nonsister chromatids form close associations called chiasmata (legs of chromosomes overlap). Tetrad with chiasmata is a synaptonemal complex
2. Metaphase I – tetrads align at plate; each pair attaches to a separate spindle
§ ***Karyotyping performed here***
3. Anaphase I – homologous pairs pulled to opposite poles (disjunction) / distribution to the two daughter cells is random w/ respect to parental origin
4. Telophase I – nuclear membrane forms around each nucleus, producing two haploid daughter cells
- Second division is very similar to mitosis. No chromosomal replication. Note that only one becomes functional gamete in females (3 polar bodies are eventually degraded, while mature ovum is produced)
Inversion – chromosomal segment turned 180o
Translocation – 2 nonhomologous chromosomes interchange genes (attachment of all or part of one chromosome to another)
***Mitochondrial DNA is an exception to the universality of the genetic code***
Nondisjunction – failure of homologous chromosomes to separate during Meiosis I or sister chromatids to separate during Meiosis II; result in trisomy or monosomy; ex Down syndrome
Turner syndrome – sterile female lacking X chromosome; monosomy
Klinefelter Syndrome = 44 autosomes + XXY
Asexual Reproduction methods – production of offspring w/o fertilization
· Binary Fission – prokaryotes (one celled amoebae, paramecia, algae, and bacteria); DNA replicates, wall grows inward along midwall to make two equally sized cells
· Budding – replication of nucleus followed by unequal cytokinesis. Develops as outgrowth, forms smaller cell that will eventually grow to adult size; ex hydra & yeast
· Regeneration – regrowth of lost body part; ex starfish, hydra, tadpole, salamander
· ***Parthenogenesis – unfertilized egg to adult organism; ex male bees and ants***
Asexual reproduction in plants
1. Spore formation- ALTERNATION OF GENERATIONS; diploid generation is succeeded by haploid generation
a. Diploid sporophyte(spore-producing plant) à Haploid spores à haploid gametophyte (sex cell-producing plant)
b. Angiosperms: dominant is sporophyte, Mosses(bryophyte): gametophyte dominant
Angiosperms - flowering plants; flower is reproductive structure
· Stamen – male organ; composed of stalk-like filament & sac-like anther (produces haploid spores that develop into pollen)
· Pistil – female organ; composed of stigma (catches pollen), style, and ovary
· Sepals – green leaves cover and protect flower bud during early development
· Fertilization – 1 sperm nucleus + 1 egg nucleus => zygote => embryo 1 sperm nucleus + 2 polar nuclei => 3n endosperm
· Seed formation – Epicotyl (precursor of leaves), Cotyledons (seed leaves), Hypocotyl (develops into lower stem and root), Endosperm (feeds embryo), Seed Coat (develops from outer covering of ovule)
2. Vegetative propagation- undifferentiated tissues in plants, meristems, provide a source of cells that can develop into an adult plant
a. Natural Vegetative propagation
i. Bulbs- split to form several bulbs (tulips and daffodils)
ii. Tubers- underground stems with buds (eyes of potatoes)
iii. Runners- stems running above and along ground that produce new roots and upright stems (strawberry and lawn grasses)
iv. Rhizomes (stolons): woody, underground stems (ferns and iris)
b. Artificial Vegetative propagation
i. Cut piece of stem can develop new roots - auxins used to accelerate root growth
ii. Layering- stems will take room when bent to ground and covered with soil (raspberries and blackberries)
iii. The stem of one plant called the scion can be attached to rooted stem of closely related plant (the stock). Cambium of both stems must be in contact for water transport
HUMAN REPRODUCTION
Gonads – male = testes, female = ovaries
Leydig cells –interstitial cells in the testes, secrete testosterone in presence of LH
Spermatogenesis – sperm production in seminiferous tubules; head = nucleus & tail = flagellum
· acrosome – lysosome containing enzymes used to penetrate the egg
prostatic fluid – secreted by prostate; helps neutralize the acidic vaginal secretions to enhance sperms’ ability to swim; also neutralizes seminal fluid (too acidic from metabolic waste of sperm)
Oogenesis – oocytes produced in ovaries
Capacitation – penultimate step in maturation of the spermatozoa while in the female, allows for egg penetration
Male Reproductive – path of sperm SEVEnUP
1. seminiferous tubules- production of sperm
2. epididymis- maturation and storage of sperm
3. vas deferens(2)- transfer sperm from both epididymis to urethra
4. ejaculatory duct
5. urethra
6. penis
Female Reproductive – fallopian tube opens to uterus (narrow end called cervix), cervix connects with vaginal canal
The Menstrual Cycle - divided into follicular, ovulation, luteal, menstruation
1. Follicular – FSH promotes development of follicle which secretes estrogen
2. Ovulation- peak in estrogen à LH surge à ovulation (midway through cycle) à mature follicle bursts releasing ovum
3. Luteal – LH induces follicle to develop into corpus luteum which secretes estrogen and progesterone-responsible for maintenance of endometrium (LH and FSH inhibited)
4. Menstruation –
o If ovum is not fertilized, corpus luteum atrophies à corpus albicans, and drop in estrogen and progesterone cause endometrium to slough off
o If fertilized, placenta produces (Human chorionic gonadotropin) hCG (estrogen + proges levels remain high)
Estrogen – thicken endometrium
Progesterone – development and maintenance of endometrial wall
Chapter 3 – Genetics
-Genes on the same chromosome will stay together unless crossing over occurs
-For a Dihybrid Cross make a punnet square that is 4X4. I.E. if the genotypes are TTPP and TtPp the four on top would be (TP TP TP TP) and on the side would be (TP Tp tP tp)