Bio test 3

Shoot system

contains both the vegetative/non reproductive parts of the plant (leaves and stem) and the reproductive parts of the plant (flower and fruit)

root system

supports the plant, absorbs water and minerals, and usually underground

types of tissue that plants have

dermal, ground, and vascular tissues

dermal tissues (plants)

protection and prevents water loss. contains the epidermis and stomata

epidermis (plants)

outer layer (skin like). Protects from diseases and absorbs water and nutrients

stomata

allows a plant to take up carbon dioxide and release oxygen and water vapor (flanked by two guards cells that regulate its opening and closing)

leaf

• contains the lamina (leaf blade)

• two types of attachments

• synthesizes sugars during photosynthesis

ground tissues

used for metabolism, storage and support

• contains parenchyma, collenchyma, sclerenchyma

parenchyma (ground tissue)

• Structure: cube shaped, loosely packed, thin walled, contains chloroplasts

• Functions: photosynthesis, cellular respiration, storage

Collenchyma

• Structure: elongated, unevenly thickened walls

• Functions: support, wind resistance

Sclerenchyma

• Structure: thick, double cell walls containing lignin

• Functions: support, strength

how is vascular tissue arranged in monocots vs dicots?

Monocots: the vascular tissue is unorganized and random

Dicots: the vascular tissue is aligned in a circle (planned)

node

point of attachment for leaves, aerial roots, and flowers

Internode

region between 2 nodes

petiole

stalk extending from stem to the base of the leaf

Axillary bud

usually found in the axil (area between the base of a leaf and the stem) where it can give rise to a branch or flower

Apical bud

the apex (tip) of the shoot contains the apical meristem (location for vertical growth)

parts of a stem

tap roots v fibrous roots

Tap root systems: have a main root that grows down

Fibrous root systems: consist of many small roots

root cross section

n

root hairs

tubular extensions of epidermal cells (increase surface area of roots for better water/nutrient absorption)

how are vascular bundles arranged in the roots of monocots vs dicots

Monocots: xylem and phloem cells form a ring around the central path

Dicots: vascular tissue forms an X shape in the center of the root

two attachments for leaves

o   Attached by a petiole

o   Attached to the plant stem (sessile)

palide mesophyll

upper layer of photosynthesis cells, just below upper epidermis

spongy mesophyll

lower layer of photosynthetic cells

leaf structure

n

how do carnivorous plants eat?

Insects are digested by bacteria; the plant then absorbs the smaller molecules

 What four things do plants need from their environment?

·      Water

·      Sunlight

·      Carbon dioxide

·      Essential inorganic nutrients/minerals

macronutrients vs micronutrients

plants need a lot of macronutrients, plants only need a little bit of micronutrients

what makes something essential

it is obtained from the environment (cannot be made by the organism)

humus (topsoil)

top-most layer of soil that is key for plant nutrient uptake. Contains high levels of water and nutrients from decomposing materials

How are minerals absorbed by plants?

Minerals are absorbed into the roots using active transport (uses energy in form of ATP)

root nodules

mutualistic relationship with bacteria for nitrogen fixation

mycorrhizae

increases surface area for mineral absorption (interaction between fungi and roots)

xylem

transports water and nutrients from the roots to leaves (UP ONLY). Strong, non-living cells at maturity that contain lignin and provide structure to plants

Contains tracheids and vessel elements

tracheids

tapered at both ends, ends overlap and pits allow water to pass from one to the next

vessel elements

long tubular with perforation plates at each end, run end to end to look like a pipeline

water potential

the mechanical energy of water, tendency of water to move from one area to another due to

·      Osmosis

·      Gravity

·      Mechanical pressure

·      Matrix effects such as capillary action (surface tension)

pressure potential

effect of pressure on water, water moves from HIGH pressure potential to LOW pressure potential

solute potential

effect of osmotic movement on water, water moves from LOW solute to HIGH solute

water will….

ALWAYS move from areas of higher water potential to areas of lower water potential

why does water move into roots

plants accumulate high concentrations of minerals just inside the root epidermis. Water is pulled into the root and, as water enters the root, it adds pressure to existing water pushing it upward.

how is root pressure created?

Ions are higher inside of the root than outside of the root causing osmosis to force water through root cells (osmotic pressure)

As water enters the root, it adds pressure to existing water and pushes it upward, referred to as root pressure and manifests are guttation. Different than transpiration

transpiration

as stomata open, water escapes into the air via evaporation

cohesion

the ability of water to stick to itself

adhesion

the ability of water to stick to other molecules

what two processes allow water to reach to the tops of trees?

cohesion and adhesion

These particles allow water to stick to the sides of xylem vessels and pull a continuous column of water upwards against gravity

is the phloem alive?

yes, alive at maturity

two parts of the phloem

sieve tube members and companion cells

sieve tube members

end walls have sieve plates with many pores and are connected by strands of cytoplasm with no nuclei

companion cells

• next to sieve tube members with many pores

• connected by strands of cytoplasm with no nuclei

• load/unload sugars into sieve tubes

pressure flow model

1. Sucrose is actively transported from source cells to the companion cells and then the sieve tube elements

2. Water potential is reduced, causing water to enter the phloem from the xylem

3. The resulting positive pressure forces the sucrose-water mixture down toward the roots, where the sucrose is unloaded

4. Transpiration causes water to return to the leaves through the xylem vessels

photomorophogenesis

growth and development of plants in response to light that allows plants to optimize their use of light and space

photoperiodism

ability to use light to track time, plants can tell the time of day and time of year by sensing and using various wavelengths of light

Phototropism

directional response that allows plants to grow towards, or even away from, light

how do plants protect themselves from herbivores?

• Bark, waxy cuticle, thorns, and spines

• Secondary metabolites

secondary metabolites

not necessary for respiration or plant growth/development and can be toxic. some discourage predators with noxious odors or repellant tastes

alternation of generations

Plants have two distinct stages (gametophyte and sporophyte)

Haploid gametophytes produce the male and female gametes by mitosis in distinct multicellular structures. These gametes fuse into a diploid zygote, which develops into the sporophyte.

Diploid sporophytes produce spores by meiosis, which then divide by mitosis to produce the haploid gametophyte.

The new gametophyte produces gametes, and the cycle continues.

layers/whorls (of flowers)

• sepals: outermost whorl

• petals: second whorl

• stamens: third whorl

• carpels: innermost whorl

carpel

female part of the flower

ovary

contains ovule (megagametophyte)

Ovary becomes fruit

Ovule becomes seed

stigma

tip where pollen lands (sticky)

style

neck or stalk leading to ovary

stamen

male part of the flower

anther

contains pollen grains (microgametophytes)

filament

holds anther up

pollination

the mechanical transfer of pollen from anther to stigma that may or may not be followed by fertilization.

double fertilization

means there are 2 sperm; one sperm unites with egg to form a diploid zygote, while the other sperm unites with the two polar nuclei to form the triploid endosperm (provides nutrients to the embryo)

self-pollination

pollen from the anther is deposited on the stigma of the same flower, or another flower on the same plant

cross pollination

transfer for pollen from the anther of one flower to the stigma of another flower on a different individual of the same species

biotic agents

insects (bees, flies, butterflies), bats, birds, and other animals

abiotic agents

wind and water (most species and many conifers by wind)

how can plants prevent self pollination?

·      Pollen and ovary mature at different times

·      Physical features on the flower prevent self pollination

·      Male and female flowers are located on different parts of the plant

·      Male and female flowers are on different plants (dioecious)

what are the 3 generations/parts of a seed

integument, endosperm, embryo

integument

•   parent sporophyte (protective covering)

o   Encloses the dormant embryo and stored food

o   Germinates when conditions are favorable

endosperm

parent gametophyte

embryo

new offspring

what are the adaptations that seeds have?

·      Maintains dormancy under unfavorable conditions

·      Protect young plant when it is most vulnerable

·      Provide food for the embryo until it can produce its own food

·      Facilitate dispersal of the embryo

what are the adaptations that seeds have for dispersal/surviving/timing

Seeds can be dispersed by animals, water, and wind. Specific adaptations ensure that seeds will germinate only under appropriate conditions (such as seeds sealed by wax in tough cones that do not open until exposed to fire- serotinous cones)

what are fruits and the layers?

fruits: mature ovaries

• pericarp: ovary wall

  • exocarp: skin or rind

  • mesocarp: flesh or pulp

  • endocarp: surrounds seeds (pit)

asexual reproduction

production of seeds without fertilization

apomixis

ovule or part of the ovary that gives rise to a new seed

stolon

stem that runs along the ground that forms adventitious roots and buds that grow into a new plant

grafting

two plant species are used: used of the stem is tied onto a rotted plant called the stock. The part that is grafted or attached is called the scion

cuttings

a portion of the stem containing nodes and internodes is placed in moist soil (or water) and allowed to root

layering

a stem is bent and covered with soil

radial symmetry

body parts arranged around central axis that can be bisected into two equal halves in any 2-D plane

Bilateral symmetry

body has right and left halves that are mirror images, with only the midsagittal plane bisecting the animal into two equal halves

front/coronal

separates ventral (front) from dorsal (back)

transverse

akin to cross-section of a stem

sagittal

divides left from right, at the midsagittal plane, left and right sides are mirror images

what factors limit the body size of animals?

·      Cell size is constrained by the surface area to volume ratio

·      Gravity

·      Drag (in water)

·      Skeleton weight (endoskeletons allow for larger body size than exoskeletons

·      Surface area: volume ratio for heat dissipation

ectotherms vs endotherms (basal metabolic rate)

ectotherms: absence of insulation increases their dependence on the environment

endotherms: maintain a relatively constant body temperature (fat, hair, feathers to insulate)

small vs large (basal metabolic rate)

Smaller organisms have a higher basal metabolic rate because they have a larger surface area relative to their mass. Active animals have a higher basal metabolic rate than inactive ones

acclimatization

changes in one organ system to maintain a set point in another organ system

positive feedback loop

maintains and potentially strengthens the response to a stimulus (blood clotting) not many biological systems

negative feedback loop

counteracts changes and reverses the direction of the change. most biological systems (temperature, glucose, pH, blood calcium levels)

what methods can animals maintain thermoregulation homeostasis

·      Radiation (heat released)

·      Convection (air/water removing heat)

·      Conduction (heat transfer form surface)

·      Evaporation (sweating)

parazoa

lack defined tissues + organs and can disaggregate and aggregate their cells (sponges)

Eumetazoa

·      have distinct and well-defined features

·      have irreversible differentiation for most cell types

·      possess unique tissues which allow coordination of movement

·      nerve tissue and muscle tissue (not in fungi and plants)