biology 355 Iowa state university exam 1

Nodes

-only occur on stems

-allows for leaves to grown off of the stem

-there are no nodes on roots

internodes

spaces between nodes

Apical meristems 2 types

-SAM: Shoot apical meristem: located at the top of the stem Its main function is to trigger the growth of new cells in young seedlings at the shoots and forming buds.

-RAM: root apical meristem Its main function is to trigger the growth of new cells in young seedlings at the tips of roots

Axillary Meristems

-Just above the node and inthe axle

-Axillary buds

To make a plant expand you have to activate the axillary meristems. In order to do this you remove the apical meristem and removes a source of oxin, which suppresses the growth.

Cuticle

waxy material secreted by the epidermal cells to reduce water loss

vascular bundle

xylem (inside) the vascular tissue in plants that conducts water and dissolved nutrients upward from the root

phloem (outside) the vascular tissue in plants that conducts sugars and other metabolic products downward from the leaves.

Lateral meristem

Occurs in vascular tissue (like the xylem and phloem)

Accounts for the growth in diameter like a tree trunk

Function of the root

-Anchoring and support

-Water and mineral uptake

-Storage of carbohydrates (produced above ground by photosynthesis but stored in the root)

Roots

-Has no cuticle and no nodes

-Phloem is between the xylem lobes

-Enclosed by the endodermis

root hairs

increase surface area for absorbtion

Lamina

The main part (blade of the leaf) is called

petiole

The little part that attaches to the stem is

Stomata

gas exchange in the leaf

All of the flowering parts are attached to a

receptacle

cortex

tissue present between the epidermis and the vascular tissue of the plants

-form the outermost layer in the root and stem.

-They usually function in storage of photosynthetic products.

-It also helps in uptake of water and minerals

pericycle

a thin layer of plant tissue between the endodermis and the phloem.

filter the water that is absorbed

pith

ground tissue internal to the vascular tissue

Sepals (calyx)

a modified leaf as part of the flower but do not have the ability to undergo meiosis

Petals (corolla)

the attractive element of the flower for animal pollinators

Stamens (androecium)

-have 2 parts

1. The long part that is thinned out is called the filament

2. The bud at the top is called the anther (produces pollen and partakes in meiosis)

stamen= filament + anther

anter

produces pollen and partakes in meiosis

pollen is

haploid

All of the stamens together are called

androecium

Pistil consists of

stigma, style, ovary

trash heap hypothesis

agriculture arose as an accident. people threw old fruit on trash heaps and plants grew--made the connection that they could intentionally grow plants

Center of origin hypothesis

-Process of domestication takes place at their center or origin

-geographical area where a group of organisms, either domesticated or wild, first developed its distinctive properties

Phenotype

Functional expression of the genotype

Genotype

The total set of alleles in the genome of an organism

Endoparasite

Inside the body

Ex. tapeworm

Ectoparasite

Outside the body

Ex. ticks

Directional selection

-Were moving the mean of a plant (ex. weight) shift more efficiently

-in which an extreme phenotype is favored over other phenotypes, causing the allele frequency to shift over time in the direction of that phenotype

Artificial selection

The breeding of plants and animals to produce desirable traits. Organisms with the desired traits, such as size or taste, are artificially mated or cross-pollinated with organisms with similar desired traits

Zones of meiosis are located at

the pistil

Individual unit of the calyx is called a

sepal

Individual unit of the Corolla is called

petal

Stigma

receptive to pollen

layers of female plant

ovary > ovule > seed

Fused carpel

syncarpellate

PROCESS IS CALLED CONDUPLIATION

folding in of the leaf

Conduplication

folding in of the leaves

Sorus

a cluster of spore-producing receptacles under a fern frond

Walls of the carpal have 3 layers

collectively called pericarp

Outermost that is exposed to the outside is derived from the epidermis is exocarp

Inner layer is the Endocarp

Middle layer is the Mesocarp

Fertile Crescent

origin of agriculture and domestication

there are archaeological findings of barley and wheat domestication

evidence found associated with domestication

dry fruits

Indehiscent fruit

stays closed and does not open at maturity

achene

One seeded fruit that is not attached to an ovary wall or endocarp

Ex. sunflower seed

Caryopsis (grain)

One seeded

The seed is fully fused to precarp

corn , wheat

Nut

One seeded, occasionally 2-3

The entire pericarp becomes woody or bonelike

Ex. acorn

Dehiscent fruits

-open at maturity

-legume

-capsule: many carpels fused into 1 pistil

legume

conduplication

dehiscent

CAPSULE

dry dehiscent fruit with many carpels

ex. POPPY and TULIP

SCUTELLUM

acts as a "placenta" transitions the proteins from endosperm to the embryo

fleshy fruits (do not Dehis)

simple fruits below

berry

All layers of the pericarp remain fleshy with many seeds

Ex. blueberry, tomatoes

Drupe

Exocarp and mesocarp are fleshy, the endocarp is stone-like

Ex. cherry, peach, plum

Pepo

The exocarp becomes leathery, the meso and endocarp both are fleshy

Ex. watermelon, cucumber, pumpkins

Hesperidium

Exocarp becomes glandular (oil-like), fleshy meso/endocarp

All citrus fruits

Pome

inferior ovary + receptacle tissue

Ex apple, pears

The flower in an apple

-Short stigma and style

-All flower parts are attached to the receptacle

-When eating an apple you eat the receptacle tissue

-Encapsulated with receptacle tissue

special fruits below

Aggregate fruit

-Aggregation of individual fruits from one flower

-Just a bunch of little fruits together in one flower

Ex. raspberry

Accessory fruit

-Seed is not attached to the inside wall of the ovary

-Achene

-The seeds are found inside the achene all over the surface of the receptacle

Ex. strawberry

-Tissue of the receptacle that is desirable for consumption

Multiple fruit

are fruiting bodies formed from a cluster of fruiting flowers, the inflorescence.

Grains (poaceae) what type of fruit are they

caryopsis

-dehiscent fruits

Major difference between grasses and dicots

-grasses have a fibrous root

-the stem is small and compact

-grass grows by producing cell division from the bottom and pushing it up

leaf of grass is called

a Sheath

the sheath is also the petiole

intercalary meristem

the growth region at the base of grass leaves that causes leaves to elongate

The importance is that the meristem is down below so you can cut the grass

grass flowers

"clam shell"

lower part of the shell is called LEMMA

upper part is called PALEA

-feathery stigma so pollen gets stuck

-male enters dangle

versatile anthers

in grass

dangling anthers

inflorescences

a group or cluster of flowers arranged on a stem that is composed of a main branch or a complicated arrangement of branches

first domesticated plant

barley

awn

protection of the lemma

panicle

so that each flower has its own stalk (called a pedicel) attached to the branch

spike

bears flowers that are directly attached to the plant, without any stalks whatsoever.

rhizome

a horizontal, underground stem that produces new leaves, shoots, and roots

stolon

a horizontal branch from the base of plant that produces new plants from buds at its tips

corn first domesticated in

tropical high elevation Mexico

most altered in domestication and reproduction

CORN DOMESTICATION

-corns ancestor is teosinte

-then people stared to cross teosinte with maze

-in mexico they first simply choose which seeds to plant (artificial selection)

-Later changes in the evolution of modern maize involved many genes (perhaps thousands) with small effects