Diversity of Life and Organismal Biology

Question 1

Cellular Organization

Answer 1

bacteria and protists- single cell and that carries out all the functions

all other organisms are multicellular

Question 2

Growth and Reproduction

Answer 2

• -all living things grow and reproduce thru cell enlargement and cell division
• -single celled organisms can grow due to cell enlargement
• -also reproduce thru cell division

multicellular period of cell enlargement followed by mitosis and also do meiosis

Question 3

Regulation and Response to Environ

Answer 3

• -regulatory mechanisms that used to maintain homeostasis

- -respond to stimuli to adjust fns and behavior

Question 4

Obtain and use energy

Answer 4

–can obtain energy from environment and use this to maintain life processes which is called metabolism

Question 5

Kingdom System

Answer 5

Contains Monera, Protista, Fungi, Plantae, and Animalia
–Recently Monera is divided into Bacteria and Archaea

Monera: single celled, lack nucleus or highly organized genetic info

• -simplest and most primitive organisms
• -first forms of life to merge on Earth

Protista: single celled, have true membrane bound nucleus

• -most have one cell, some are multicellular
• -lots of diversity

Fungi: multicellular, includes mold, yeast, and mushrooms
–cell walls, can absorb nutrients, unique structures and modes of reproduction

plantae: photosynthesis and have chloroplasts
animalia: diff modes of nutrition, cell structure, and ability to move

Question 6

Domain System

Answer 6

• -Dividing factors bw domains is rRNA is unique to each domain of organisms
• -within this system all living things are placed into Archaea, Bacteria, or Eukarya

Archaea and Bacteria-prokaryotes, lack nucleus and are unicellular
Archaea domain mostly archaebacteria, some are extremophiles which means thrive in high temp, acidity, and lack of oxygen

Bacteria: almost anywhere, more primitive
Protista, fungi, plantae, and Animalia in Eukarya domain
—therefore they all have membrane bound nucleus
–and undergo complex cell division and reproduction
–have organelles and cell components not found in prokaryotes

Question 7

Structure

Answer 7

DNA core- contain nucleic acid
RNA core
capsid (protein coat)- contains genetic material of virus
–viral structures not considered cells bc do not have organelles to reproduce or perform other cell fns

prokaryotic structure: lack membrane bound nucleus, lack of membrane bound organelles, DNA as single chromosome and circular

both archaea and bacteria- filled with cytoplasm, nonmembrane bound ribosomes, cell wall

• -components of cell wall differ bw these two
• -archaea cell walls lack peptidoglycan which IS found in bacteria
• -bacterial cell wall for strength and lets materials nutrients come in/out
• -eukaryotic cells: nuclear membrane composed of 2 layers of phospholipids which protect and regulate materials
• -also contain mitochondria, Golgi, ER, and lysosomes
• -fungal cells also have above aforementioned organelles and a cell wall (chitin)
• DNA bacteria like, also distinct nucleus with membrane

plants have cellulose cell wall and membrane bound chloroplasts

animal like protists - cell membrane
plant like protists: cell wall and chloroplasts
others coated with pellicle (surrounds outer cell membrane)

Question 8

Organization

Answer 8

bacteria, and archaea, many protists, and some fungi are unicellular

• -are prokaryotic and eukaryotic that are unicellular, some live in colonies
• -colony: symbiotic, mutually beneficial
• • each cell live independently of one another and does not specialize
• -multicellular eukaryotes: some protists, algae, most fungi, single celled yeast, all plant and animals
• -their cells specialize to perform specific functions

Question 9

Modes of Nutrition

Answer 9

–autotrophs: self nourishing organisms
=produce own food using internal processes
=must obtain carbon and energy source
=break down carbon into usable energy

2 kinds of autotrophy
=photosynthetic: plants, plant like protists, some bacteria
=chemosynthetic: sulfur and ammonia as energy

–heterotrophs: get from other sources
=energy from org matter
=rely on autotrophs
=consume autotroph material thru ingestion and absorption
=animals, fungi, most bacteria, animal like protists

Question 10

Reproduction/Replication

Answer 10

viral replication: virus binds to living cell and injects its genetic material into host

• -uses host cells mechanisms and enzymes to replicate
• assemble into clones

lytic cycle: host cell broken apart and killed as the viral clones released

• triggered by lytic enzyme
• lysis after viral cloning

lysogenic cycle: viral genetic material integrates with the genome of host and replicates each time the host cell divides

• -lysis occurs when host deteriorates and virus ends dormancy
• -lytic enymes released in order to release clones

binary fission: bacteria and archaea reproduce, is a form of asexual cell division, parent cell into 2 daughter cells

protists: binary fission, sexual and asexual
- -asexual: budding: offspring produced from specialized generative site on parent body

yeast fungi, plants, can reproduce via budding

fungi: asexual and sexual reproduction
- –fragmentation (asexual): parent divides into pieces
- -sporulation: parent does mitoses to create clones
- sexual: parent undergoes meiosis to make gametes to be released for fusion with another

some plants and animals can reproduce via budding, fragmentation, sporulation

Question 11

Body plans

Answer 11

shape of animals body

• symmetry
• -radial: body parts arranged circularly around central point
• -includes phylum Cnidaria (jellyfish and coral) and Echinodermata (sea stars and sea cucumbers)
• -bilateral: left and right side, head and tail
• -includes most animal phyla
• -includes phylum Chordata, Anthropoda, and Annelida (all have segmented bodies that have repeated parts/compartments)
• -assymetrical: irregular, no pattern
• -includes phylum Porifera (sponges)

Question 12

Body cavities

Answer 12

within animal phyla
Coelomates- fluid filled cavity with mesoderm lining (embryonic layer, gives rise to bones, cartilage, blood, etc)

coelom: mesoderm lined cavity. surrounds digestive tract, protection and space
- -for Chordata and Echinodermata

pseudocoelomates: functional body cavity, not lined with mesoderm
- -includes Nematoda and Ronifera

Acoelomates: lack body cavity
–Porifera, Cnidaria, Plathyhelminthes

Question 13

Modes of Reproduction

Answer 13

asexual and sexual

asexual: offspring produced from single parent
- -includes Parthogenesis: development of embryo from unfertilized female gamete
- -and regeneration: parts regenerate

budding and fragmentation ( new ind from part of parent)

hermaphrodites: sexually and self fertilization

Question 14

Modes of Temp. Regulation

Answer 14

ectotherms: internal body temp regulated by environment
- -can slow body processes
- -live where little temp variation

endoderms: self regulate internal body temp
- -phylum Chordata: mammals and birds
- -can live in extreme temp

Question 15

Cells

Answer 15

unicelluar vs multicellular

Question 16

Tissues

Answer 16

group of specialized cells that work together to perform a similar function

Question 17

Organs

Answer 17

composed of tissues that perform a similar function
not composed of identical tissues and specialized cells
many diff tissues that work to perform complex function

Question 18

Organ Systems

Answer 18

multiple organs that function together

organisms: collection of organ systems that work together to perform all functions

Question 19

Cardiovascular

Answer 19

Cardiovascular

• organs that transport materials (nutrients, waste, gases) from one area to another
• -transported thru blood which delivers food and oxygen and removes waste
• porifera (sponges)- lack circulatory system, must absorb oxygen
• arthopods and mollusks have open circulatory system, blood doesnt travel via blood vessels
• vertebrates: closed circulatory system

closed circulatory system:

• –heart- pumps oxygenated blood to body parts via arteries (withstand pressure)
• –capillaries: branch off of arteries, oxygen, nutrients and materials exchanged
• –veins: carry deoxygenated blood back to heart

humans: 4 chambered heart
- 2 atria: receive blood
- 2 ventricles: pump blood
- oxygen poor into right atria (separates it from right ventricle
- valves pushed open
- blood enter right ventricle
- right ventricle pumps into lungs
- oxygen absorbed in lungs
- blood goes to left atria (bicuspid separates it from left ventricle
- enters left ventricle which pumps blood to rest of body

blood pressure: heart pumps blood and exerts pressure on vessels

• -systole
• -diastole

Question 20

Reproductive

Answer 20

gametes made in gonads
gametes haploid
gametogenesis: production of gametes
–cell must go thru meiosis to specialize into gamete

sperm-made in testes

• -each testes had coil tube which is initial site of spermatogenesis
• -cells go from spermatogonia into spermatocyte and eventually become sperm
• -as sperm mature they move on for development, storage, or ejaculation
• -sperm first go to epididymis for final development
• -here they develop head (chromosomes located) and flagellum
• -then to vas deferens which carriers sperm to urethra
• -mixes with nutrients and fluids and this is now semen

oogenesis: egg production
- -within ovaries
- -oocytes undergo meiosis
- -divide and become follicles
- -egg goes to fallopian tube
- -if fertilized it will go to uterus and if not menstrual cycle

Question 21

Digestive and Excretory

Answer 21

• -maximize nutrients absorbed (used in cellular resp. and energy production
• -ingestion and digestion
• -absorption:
• -excretion
• sponges: use cilia to move food into gastrovascular cavity
• intracellular digestion: cnidarian, platyhelminthes, echinoderms: incomplete digestive system, one central opening, food digested in cytoplasm of cells that line cavity
• -complete digestive system (extracellular digestion): annelids and anthropods and vertebrates
• —mouth and anus
• -peristalsis (muscular contractions)
• -accessory organs (liver and gall bladder): aid in digestion and absorption of nutrients

digestion can be mechanical or chemical

steps: mouth for chewing, pharynx for swallowing, to esophagus for transport to stomach, stomach for storage and more digestion
- -in stomach are muscle contractions and secretion of juices called pepsin (digesting enzyme) to break down macronutrients

chyme: mixture of food and digestive juices
- -moves from stomach to small intestine (majority of absorption and digestion)
- -chemicals produced by pancreas, gall bladder complete chemical digestion
- -villi: folds in small intestine that inc SA for max absorption
- -small intestine to large intestine for final digestion to be excreted

• -large intestine absorbs water and nutrients left
• -chyme goes to colon for max reabsorption of water
• -waste to rectum (end of large intestine)
• -kidneys: processes and excretes excess fluid
• -urinary system
• -filters waste from blood and removes it
• -ureters to bladder
• -urine stored in bladder and released thru urethra
• -excess fluid thru skin via sweat glands
• gas waste thru lungs

Question 22

Nervous System

Answer 22

Nervous System:

• respond to environ
• transmit nerve impulses
• neurons transport those impulses

neuron: cell body (nucleus), dendrites (recieve impulses), axon (transmits signal)
- -synapse: trigger receiving neuron to receive and transmit impulse
- -sensory receptors: receive info from outside stimulus, and sends info thru nervous system

• -sponges (no nervous system)- contract when touched
• -cnidarians, echinoderms: nerve nets, sense stimuli and send messages without brain or central nervous system
• -animals with bilateral symmetry: CNS and PNS
• -invertebrates (mollusks, anthropods, annelids) have this

CNS: brain and neurons called ganglia

• -forebrain: cerebrum (conscious thought, movements, higher thinking, memory)
• -thalamus (processes sensory info) and hypothalamus (regulates involuntary movements)
• -midbrain: visual and auditory, sends sensory info
• -hindbrain: pons (bridges info) and medulla oblongata (connects spinal cord and brain, regulates autonomic body activities)
• -cerebellum: balance and equilibrium

brainstem: pons, medulla oblongata, and hindbrain

spinal cord: mass of nerve cells, impulse communication (to and from brain) and reflexes (not transmitted to brain)

info in nervous system goes from PNS to CNS and back

• nerves are collection of neurons
• nerves can be motor or sensory (both are cranial nerves)

PNS is somatic and automonic

• spinal nerves (somatic nervous system): voluntary control
• autonomic: involuntary (heart, digestive, circulatory, endocrine)

autonomic divided into sympathetic and parasympathetic

• –sympathetic: fight or flight, metabolism, raise heart rate
• –parasympathetic: rest or digest, slow heart rate, slow breathing

Question 23

Immune

Answer 23

defend against pathogens
microbes: bacteria, viruses, and fungi

animals with skin: physical barrier
animals with respiratory and digestive: cilia, tears, and mucus, saliva to trap, transport, or kill

innate immune system: physical barriers

• -example: inflammation, release histamines to raise temp and inc blood flow, so WBCs enter
• -fever: innate response
• -phagocytes: nonspecific defense, WBCs that engulf pathogens, present in every body tissue

adaptive immune system: specific defenses, target specific pathogens based on their properties

• -properties expressed as antigens
• -develop immune response
• -lymphocytes: WBC produced bc of immune response
• —T cells (detect antigens) and Helper T cells bind to antigen
• —Helper T cells can stimulate cytotoxic T cells to destroy cells in cell mediated response, must bind to cell surface
• –Helper T cells also can stimulate B cell production in antibody mediated response
• –2 kinds of B cells (plasma cells and memory cells), B cells make antibodies which bind to antigen and neutralize
• –B cells stimulate phagocytes ingest
• –result in immunity

Question 24

Role of Structural Components (kidney, hypothalamus)

Answer 24

hypothalamus: link bw nervous and endocrine system
- -receives sensory stimuli, interprets info, secretes hormones or makes pituitary to bring body back to normal

kidney: maintain fluid balance (blood, urine, sweat)

Question 25

Feedback Mechanisms

Answer 25

–communication bw multiple organ systems

–negative feedback: external change occurs that result in internal response, stop initial negative response to result in homeostasis

–positive feedback: exacerbates initial response, does not maintain homeostasis

Question 26

Role of Hormones and Behaviors

Answer 26

hormones: driving force of endocrine system (homeostasis)
- -sent to target cells or organs affected by stimulus, transmit messages to stop reduce it
- -maintain internal stability is secreted appropriately

estrogen and progesterone: must be in balance

TSH: produced by pituitary when hypothalamus detects low levels, stimulates thyroid gland to produce hormones for bone growth

thyroxine: brings body back to homeostasis, produced by pituitary

ADH: when blood pressure is too low therefore increase water to inc BP and bring back to homeostasis, the posterior pituitary stimulated to release
–controls how permeable the kidney ducts are to water and therefore impacts how much water it can conserve or release

melatonin: maintains internal clock
- -animals alter behavior to maintain homeostasis
- -in response to environment
- -sleeping patterns (diurnal and nocturnal

basking: done to maintain safe internal body temp, respond to environment
- -endothermic: controlled by hypothalamus
- -ectothermic: cannot internally alter environment, move location, go out in sun or burrow depending on temp they want to be

Question 27

Gamete Formation

Answer 27

already covered

Question 28

Fertilization

Answer 28

already covered

Question 29

Embryonic Developmental

Answer 29

fertilization: fusion of gametes to produce zygote
- -external and internal
- -if fertilization them embryogenesis
- -first stage is cleavage, zygote divides
- -forms morula, interior cavity made
- -then blastula which forms gastrula
- -gastrulation (2nd stage): germ layers form, which will become specialized cells, tissues, and organs

ectoderm: outer layer, become nervous system, skin, sensory organs
mesoderm: musculoskeletal system, cardiovascular, reproductive, kidneys
endoderm: respiratory, liver, pancreas, digestive, lungs, bladder

• organogenesis: organ development begins
• germs layers also begin to develop tissue
• notochord develops -support and helps develop neural tube (spinal cord and brain)

oviparous: laying eggs outside of female
- -hatch as larva, must undergo metamorphosis
- -nutrients to baby via yolk sac

ovoviviparous: some animals, some invertebrates, fish, and reptiles
- -embryos in eggs inside mother

viviparous: most mammals, embryos develop inside mother and directly receive nutrients

placental mammals: attached via umbilical cord, get nutrients, oxygen, and rid of waste

Question 30

Growth, Development, and Aging

Answer 30

• TSH
• for bone growth
• hypothalamus detects metabolism has been alatered from ageing, diet, stress. etc

Question 31

Vascular vs nonvascular plants

Answer 31

Non-vascular:

• -bryophyte: land plants such as mosses, liverworts, and hornworts
• -multicellular, more complex than algae, lack specialized tissues and organs
• -no distinct root and shoot system
• -many have rhizoids
• -no vascular system
• -reproduce by spores

Vascular:

• -specialized xylem and phloem
• -allows them to grow taller, wider, and heavier
• -more specialized tissue for diff fns
• -ferns, fern allies (pteridophytes)
• -leaves, stems, roots
• -produce sexually by releasing spores

Question 32

Flowering vs. nonflowering plants

Answer 32

Vascular: seedless or seed plants

–pteridophytes: seedless, spores released into air and develop gametes that are then released for fertilization

–seed plants: reproduce by fertilizing eggs then releasing seed, seed has embryo, nutritional source, and hard coat, and is dispersed by parent for germination and maturation

seeds plants: gymnosperms (nonflowering) and angiosperms (flowering)

• -gymnosperms: conifers, cycads, gnetophytes, and gingkos (seeds released without protective coat)
• -no flower structure-
• -reproductive structure in cones (pines and conifers)
• -woody, perennial plants, thin scaly leaves

angiosperms: majority of plant species
- -now dominant over gymnosperms
- -attract animals which increases fertilization and seed dispersal
- -woody (perennial), herbaceous (annual), therefore no secondary growth

Question 33

Monocot vs Dicot

Answer 33

–cotyledons: seed leaf, embyronic seed state, sotres nourishment for developing embryo

• -monocot: one cotyledon
• -dicot: 2 cotyledons

monocots: small herbaceous plants, primary growth
dicots: vary in size, secondary growth, tall woody plants

monocots and dicots vary in terms of leaf, root, stem and flowers

Leaves

• -monocots: narrow and parallel leaf veins
• -dicots: broader, reticulate leaf veins, arranged in branching net-like pattern

Stem

• -monocots: vascular bundles scattered in stem
• -dicot: vascular bundles in ring like pattern
• -monocot: lack collenchyma and vascular cambium, therefore no lateral growth
• -dicots: grow laterally and develop bark and wood

Roots:

• -monocot: adventitious therefore fibrous and descend from stem, shallow growth not deep into soil
• -dicots: taproot system to anchor deep, develop into radicle, roots branch out from taproot

Pollen structures

• -monocot: angiosperms have openings in pollen wall called furrows if elongated or pores if circular
• -monocot: pollen grains have single furrow or pore
• -dicot: pollen grains have 3

Flower Parts

• -monocot: arranged inn multiples of 3
• -dicot: arranged in multiples of 4 or 5

Question 34

Dermal

Answer 34

• -surface
• -epidermis (outer layer)
• -single layer
• -prevent water loss, defense
• -covered with waxy cuticle (barrier, prevents water loss)

root hairs: inc SA to absorb water, specialized epidermal cells

periderm: bark, several layers
- -replaces epidermis
- -phellem: cork (nonliving), waxy suberin found througout cell walls, cork is for insulation and protection

Question 35

Vascular

Answer 35

• -transport material
• -2 types: xylem and phloem (exist in vascular bundles)

phloem: transports sugars produced by leaves downward
- -via sieve elements (run throughout plant)
- -companion cells pack sugars into sieve elements and these are then filled with water
- -combined pressure moves sugars down
- -excess sugar stored until needed when phloem will move it up and break it down to be used

xylem: transports minerals, water, and other nutrients absorbed by roots upwards by cohesion tension
- -composed of tracheids and vessel elements (long tubes)
- -both non living material
- -tracheids more efficient

cohesion tension

• -begins at leaves
• -transpiration
• -water loss drop in pressure
• -pressure creates tension
• -pushes water up
• -water in xylem undergoes cohesion
• -stomata close and pressure drops, water adheres to cells in plant

root pressure: when transpiration is low roots absorb more water

• -roots have high conc of minerals
• -water moves in to these areas during osmosis
• -this inc pressure in roots and forces water up xylem

stems grow thicker and tougher, develop meristem or bark (this happens as more xylem and phloem develop)
cork layer: outer layer of periderm
vascular cambium: source of growth in bark
–cells divide in vascular tissue and become either xylem or phloem

Question 36

Ground

Answer 36

• -majority of tissue
• -3 types of cells
• -parenchyma
• -sclerenchyma
• -collenchyma

parenchyma

• -undifferentiated
• -divide and renegerate
• -leaves, stems, bark, roots
• -metabolism, photosynthesis, structure, growth
• -work with vascular tissue in water and food transport
• -support and structure surround vascular bundles
• -fleshy material in mature ovary
• -repair damage
• -make up mesophyll layer and cortex and pith
• -pith: also for carb and water storage in roots and stems

parenchyma differentiates into schlerenchyma and collenchyma

• -schlerenchyma: unliving in mature state,
• -cellulose and lignin to harden and reinforce
• -plant shape and structure
• -produced in vascular cambium
• -fibers and sclereids

collenchyma: plant growth and structure
- -lateral and vertical growth for young plants most
- -living at maturity
- -flexible
- –cellulose and pectin
- -rapid growth: leaves and shoots

Question 37

Meristems

Answer 37

• -parenchyma, schlerenchyma, and collenchyma arise from this
• -undifferentiated cells that give rise to differentiated cells, tissues, and organs
• -meristematic cells where new plant growth occurs, at ends of roots and shoots
• -allows plant to grow continuously
• -meristem tissue: apical (growth and length) and lateral (secondary growth and thickening)
• -apical meristems: at roots and shoots
• -also found at nodes (bw leaf and stem)
• -buds (undifferentiated meristem) arise from nodes
• -intercalary meristem: at nodes of some plants, they grow at each node
• -lateral meristem: woody plants, perennial trees and shrubs
• -vascular cambium: bw xylem and phloem has meristematic tissue that give rise to wood (secondary xylem and phloem)
• -cork cambium: within secondary wood tissue, meristematic tissue that makes phellem

Question 38

Flowers

Answer 38

• angiosperms
• -flowers: reproductive structures
• -emerge at pedicels (modified stem)
• -base of pedicels are sepals
• -petals (attract pollinators): reproduction
• -stamen: male reproductive structure
• -have a filament (stalk like) and anther (produces sperm)
• -pollen grains: contain sperm
• -pistil: female reproductive structure
• -contains stigma (receives pollen), at tip of pistil
• -style: extends stigma above flower
• -ovary: site of fertilization, egg maturation, and development
  carpel: individual style, stigma, ovary structure
• -pollen grains deposited at stigma
• -pollen grain germinates and forms pollen tube that grows down style toward ovary
• -wall of ovary thickens after ovule fertilized
• -ovary becomes fruit
• -fertilized ovule is seed
• -division of zygote, then embryo then seed
• -seed is enclosed in endosperm for nutrients
• -released, and germinates in soil

Question 39

Alternation of generations

Answer 39

• -referred to as metagenesis: life cycle unique to plants
• -plants alters bw 2 genetically distinct generations, a diploid form and a haploid form
• -diploid gen are sporophytes, therefore they undergo meiosis and make 2 haploid cells (not 4 like in humans)
• -haploid cells (spores) undergo mitosis and develop into new plant known as a gametophyte
• -gametophyte makes female and male gametes by mitosis
• -when fully developed gametes are released for fertilization
• -the gametes fuse and make embryo which gives rise to new diploid sporophyte
• -in bryophytes the gametophyte gen is dominant and they spend most of their reproductive lives in haploid state which is larger than the sporophyte
• -pteridophytes, gymnosperms, and angiosperms the sporophyte is large but gametophyte is small

Question 40

Pollination Strategies and Seed Dispersal

Answer 40

• -pollination: seed plants, when pollen grains of male plant transported and inserted into female
• -rely on water, wind, and animals (allochory)
• -seed dispersal also relies on those 3

gynosperms and angiosperms: rely on wind
gymnosperm pollen grains released with air sacs
–pines pollen are winged so can be carried

water plants rely on water for pollination
–lightweight and bouyant

• -angiosperms: wind, common among grasses and oaks
• -animal pollination more common for angiosperms
• -do so via nectar, petal color, flower fragrance
• -pollen grain attach to animal

-some plant seeds rely on gravity to drop seed into ground below (explosive dehiscence)

Question 41

Xylem Transport

Answer 41

covered

Question 42

Control

Answer 42

covered

Question 43

Products

Answer 43

covered

Question 44

Phloem Transport

Answer 44

covered

Question 45

Storage and support molecules

Answer 45

covered

Question 46

Storage Structures

Answer 46

covered

Question 47

Characteristics of Living Things

Answer 47

reproduce and pass on traits
made of cells
homeostasis
metabolic activities
respond to stimuli
grow

Question 48

Endocrine System

Answer 48

Endocrine:

• -secretes hormones into blood to regulate and control body
• -produced in response to stimuli
• -maintain fns of ANS
• -hormones transmit chemical messages by binding to receptor molecules on target cells

neurosecretory cells: invertebrate phyla have, produce neurohormones
–found in mollusks, annelids, arthopods

insects: use secretions from neurosecretory cells for metamorphosis and molting

chordates: complex endocrine system, organs and endocrine glands (pituitary, hypothalamus, pineal glands, thyroid and parathyroid, thymus, adrenal glands, pancreas, and gonads)
- -hypothalamus: direct pituitary gland to release hormones
- -pituitary gland : makes other glands produce hormones via trophic hormones
- —posterior (receives hormones from hypothalamus and releases as needed) and anterior (produced its own hormones and releases them directed by hypothalamus)

Question 49

Respiratory

Answer 49

Respiratory

• -carbon must be removed from body
• -respiration: exchange of gases between atmosphere and cells

direct diffusion: simple small animals, body cells close to environment, exchange O2 and CO2 directly thru their cells

large complex animals have respiratory system

animals in water have respiratory systems that use gills which have branches that incr surface are and maximize oxygen obtained

terrestrial animals
-tracheae, lungs, thoracic cavity, diaphragm

mammal respiration; pulmonary ventilation

• -inhalation: thoracic cavity expands and diaphragm contracts
• -cilia and mucus filter out particles that enter trachea
• -trachea to left or right bronchi
• -into bronchioles then alveoli
• -alveoli: gas exchange with blood

external respiration: carbon dioxide expelled during exhalation

larynx: top of trachea, produces sound, speech, removes particles when cough, sneeze

Question 50

Stems and Leaves

Answer 50

• -vegetative part of plant
• -capture energy and CO2 to drive photosynthesis and transpiration

Leaves

• -blade (upper side: high conc of chloroplasts)
• -petiole (connects leaf to stem)
• -sugar moved thru petiole to stem
• -stomata: underside of leaves
• -2 guard cells border stomata, swell and stretch open
• -night falls these collapse and close
• -role in regulation of water
• -most water lost thru here during transpiration (cools off plant)
• -prevent excess water loss

Stems
–structure and transports sugars to rest of plant

Question 51

Roots

Answer 51

• -majority of water absorbed thru root
• -absorb water and nutrients via root hairs and transport to rest of plants
• -root hair: outer epidermis of root into soil
• -then to cortex (under epidermis)
• -food and nutrient storage and structure
• -then endodermis
• -regulates amt of material that can go to vascular tissue
• -pericycle b4 vascular
• -grows branch roots, extend into soil
• -vascular tissue transports water and nutrients to other parts (vascular cylinder)
• -growth of root (4 zones)
• -zone of maturation: cell differentiation
• -zone of cell elongation
• -meristematic zone: cell division (mitosis), undifferentiated cells
• -root cap protects meristematic