biology 1409 lecture exam 2

what is the vegetative part of the plant body?

shoot and roots

what does a stem consist of?

nodes where leaves attach and internodes between leaves where the stem elongates

what is vascular tissue in plants?

conducting tissue

what is xylem?

transports water, dissolved minerals, and hormones from roots upward

what is phloem?

transports hormones, carbohydrates, and other substances throughout a plant

Parenchyma cells?

• alive at maturity

• have thin cell walls

• function in metabolism or storage

Collenchyma cells?

• alive

• provide elastic support to growing shoots

Sclerenchyma cells?

• long fibers and shorter sclereids

• dead at maturity

• support plant parts that are not growing

Tracheid?

• must die first before being functional

• provide structure and rigidity

• conduct water and minerals in xylem

what strengthens xylem cell walls?

lignin

what layer of the tree is alive?

the cambium layer

why is maple syrup more expensive?

it uses xylem sap

what is NOT a vegetative organ in a plant?

flower

What is an example of a specialized plant stem that you can buy in the produce section of the grocery store?

yellow onion

what is a supportive cell type with a thick secondary cell wall?

Sclerenchyma cell

where do tracheids occur in stems?

vascular bundles

what plant tissue has cells that are dead at maturity?

xylem

if you spray herbicide onto a weed, which barrier might prevent the chemical from entering the leaves?

the cuticle

the ability of a sunflower plant to become taller is directly due to its

apical meristem

what structures provide abundant surface area for water and mineral absorption?

root hairs

ground tissue occupies the ____ ?

stem pith

root cortex

leaf mesophyll

what tissue type occupies most of the volume of a woody stem?

secondary xylem

what is determinate growth?

plants stop growing when they reach their mature size

what is indeterminate growth?

plants will grow indefinitely

what are meristems?

a localized collection of cells that retain the ability to divide throughout the life of a plant

what does topsoil contain?

humus; reservoir for water and nutrients

erosion?

destroys topsoil and hinders plant growth

what does xylem transport rely on?

cohesion

what is an example of a sink in plants?

root or a flower

what structures might a water molecule flow as it moves through a plant?

sieve tubes

tracheids

vessel elements

how does water move through xylem?

it enters at roots, and cohesion pulls it to the leaves

the main function of stomata is to allow for ?

transpiration

what process creates the pressure gradient that drives phloem sap toward sinks?

1. water moving by osmosis into the sieve tubes at sources

2. water moving by osmosis out of sieve tubes at sinks

where do the simple sugars in phloem sap originate in most plants?

photosynthetic cells in leaves

which of the following is typically NOT a sink?

a mature leaf

in contrast with a typical plant, a parasitic plant . . .

extracts nutrients from another plant

what does xylem sap consist of?

mineral nutrients and water

what does phloem sap consist of?

water and sugar

what do plants produce during their sporophyte generation?

spores

what do spores develop into?

haploid gametophytes

what do plants produce during their gametophyte generation?

gametes

what exactly are flowers?

reproductive structures built of whorls of parts

which sex are microspores?

male

which sex are megaspores?

female

what determines the sex of the cells in plants?

whether they divide in the pollen sacs or ovules

what are sepals and petals?

accesory parts

gibberellins?

stimulate cell division and elongation; help break seed dormancy

Ethylene?

a gas that speeds ripening, senescence, and leaf abscission

phototropism?

plant grows toward the light

Gravitropism?

growth toward or away from the direction of gravity

what helps plants detect gravity?

statoliths (starch rich)

Thigmotropism?

growth directed toward or away from a mechanical stimulus such as wind or touch

although gametes are produced via _____ in plants, genetic variation is primarily the result of _____ ?

mitosis ; meiosis

which of the following is NOT a flower structure typically associated with reproduction?

sepal

what are the products of double fertilization?

• a diploid zygote

• triploid endosperm

a fungus secretes hormones that cause “foolish seedling” disease in rice. The shoots of infected plants grow so rapidly that they fall over from their own weight. Which plant hormone causes these effects?

gibberellin

what is double fertilization?

when one female gamete unites with two male gametes

what is grafting in plants?

the process of joining two plants together to grow as one (i.e. why we can grow peaches and apples in texas now)

coevolution?

a genetic change in one species selects for subsequent change in another species and vice versa

define cohesion

the attraction of water molecules to one another

define fruit

seed-containing structure in angiosperms

what is the carpel part of the flower?

• female part of a flower

  • has ovary, style and a stigma

define photoperiod

day length

what is a petal?

flower part interior to sepals

what is a sepal?

part of the outermost whorl of a flower

what is a stamen?

• male flower part interior to petals

• has a filament and an anther

what is a whorl?

a whorled arrangement of leaves, sepals, petals, stamens, or carpels that radiate from a single point

what is the correct order of organization of an animal’s body?

cells ; tissues ; organs ; organ system

epithelial tissue consisting of multiple layers of flattened cells is called

stratified squamous

which of the following features do all types of connective tissue share?

Each cell contacts an extracellular matrix

whereas the primary function of neurons is to _____, neuroglia have many roles, including _____

convey information; guiding nervous system development

ovaries produce gametes and hormones; these organs therefore belong to the systems

reproductive and endocrine

which of the following scenarios does NOT illustrate negative feedback?

in childbirth, contractions stimulate the release of oxytocin, which induces more contractions

The inner layer of skin is ____ , whereas the outer layer is ________

dermis ; epidermis

How does the integumentary system influence homeostasis?

• prevents water loss

• sensing external temperatures

• prevent infection

some cells of the central nervous system are located in the ?

spinal cord

what characteristic distinguishes dendrites from axons?

Direction of impulse transmission relative to cell body

what even triggers an action potential?

Opening of sodium channels

Ordinarily, a neuron’s trigger zone is activated before any other part of an axon, so a wave of action potentials occurs as voltage-gated sodium channels open in the direction of the synaptic terminal. What would happen if you artificially stimulated an axon to reach threshold potential midway along its length rather than at the trigger zone?

1. action potential would occur in the direction of the synaptic terminal

   1. action potentials would occur in the direction of the trigger zone

which of the following examples of synaptic integration is most likely to lead to an action potential in a postsynaptic cell?

All excitatory and no inhibitory synaptic inputs

which division of the nervous system is responsible for a rapid heartbeat?

autonomic and parasympathetic

the part of the human brain involved in coordinating muscle movements is the

cerebellum

damage to the surface tissue of the spinal cord will most likely affect

communication between the peripheral nervous system and the brain

underdevelopment of the medulla oblongata could lead to

erratic changes in blood pressure

as you snuggle into bed, you feel the weight of the blankets on your body, but you soon become unaware of the covers. What has happened?

Your skin’s touch receptors have adapted to the feeling of the blankets

which type of sensory receptor enables you to feel the position of your legs, even if a table hides your legs from sight?

proprioceptor

in what way are the senses of smell and taste different?

we can smell chemicals from distant objects, whereas taste is limited to chemicals at close range

the structures that enable bees to see flowers are

ommatidia

what is the function of hair cells in the cochlea?

transduce sound waves into neural impulses

the effect of a water-soluble peptide hormone such as insulin is generally quicker than that of a steroid hormone such as estrogen because

steroid hormones trigger the synthesis of new proteins

the parathyroid gland releases hormones when…

blood calcium levels are too low

which of the following glands releases hormones when the thyroid hormone concentration in the blood is too low?

hypothalamus

which hormone is lipid-soluble and helps conserve water?

aldosterone

The body receives a series of stress-inducing stimuli throughout the day. In response, glucocorticoids are released from the

adrenal cortex

Secretion of melatonin is regulated by

light

to increase male fertility, it would be logical to develop a drug that boosts hormone synthesis at any of the following structures EXCEPT the

thyroid

exoskeletons differ from endoskeletons in…

• ability to protect animal from outside

• ability to grow along with an organism

The axial skeleton is to the appendicular skeleton as

a car’s body is to its wheels

Bone matrix is composed of ——, which give bones flexibility and strength, and ———, which give bones rigidity

collagen proteins ; minerals

the function of a ligament is to connect 

bone to bone