Chapters 44-50 Test

Question 1

types of nitrogenous wastes

Answer 1

ammonia
urea
uric acid

Question 2

ammonia

Answer 2

Pro: least energy intensive
Con: toxic
most common in aquatic species
very soluble in water

Question 3

urea

Answer 3

Pro: less toxic than ammonia
Con: More expensive energy
common in mammals
medium solubility

Question 4

uric acid

Answer 4

Pro: less toxic than ammonia
Con: more expensive energy
stored in eggs
excreted as a paste
least solubility in water

Question 5

what is the function of antidiuretic hormone

Answer 5

found in the endocrine and excretory system
it is released from the pituitary gland and goes into the bloodstream to the target cells along the collecting duct. It binds to receptors along the collecting duct and causes aquaporins to form in the cells to reabsorb water back into the body cells. (negative feedback)

Question 6

role of testosterone and its signal transduction pathway

Answer 6

it is an internal cytoplasmic receptor
it can easily go through the plasma membrane to the receptor in the cytoplasm. It then goes into the nucleus and causes transcription of a G so a product is made
it causes more RNA transcription
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Question 7

what role does thyroxine play an what causes the release of it from the thyroid gland

Answer 7

thyroxine is the main hormone secreted into the bloodstream by the thyroid gland. Thyroxine increases metabolism.
When the levels are elevated the anterior pituitary gland stops the production of the thyroid stimulating hormone which doesn’t allow the thyroid to be stimulated and thyroxine is not released.
When the levels are too low the anterior pituitary gland allows the production of the thyroid stimulating hormone which causes the thyroid to be stimulated and thyroxine to be released.

Question 8

Oogenesis

Answer 8

meiosis in females
production of one egg and three polar bodies
the secondary oocyte is actually ovulated from the ovary and doesn’t technically become an egg until it is fertilized

Question 9

what is a polar body

Answer 9

cells that never become eggs through the production of meiosis

Question 10

spermatogenesis

Answer 10

meiosis in males

production of sperm (four sperm) that develops in the seminiferous tubules

Question 11

LH/FSH graphs

Answer 11

high levels of LH/FSH is occurring right before ovulation and at the end of the follicular phase as well as at the end of the proliferative phase in the menstrual flow

Question 12

what is the purpose of the cortical reaction

Answer 12

fast block
occurs after the sperm penetrates the egg-it causes the cortical envelopes to be released and causes the receptors to break off creating a fertilization envelope

Question 13

in animal embryonic development, what kinds of things happen

Answer 13

this all occurs very quickly
three parts:
1) cleavage-where the cells carry out the S (DNA Synthesis) and M (Mitotic) phases of the cell cycle but skip the G1 and G2 gap phases resulting in the embryo not enlarging significantly during this period of development
2) gastrulation-where the germ layer is formed
3)Organogenesis-the migration of cells to certain parts of the embryo and organ regiments develop

Question 14

what causes a rapid change in the membrane potential during an action potential

Answer 14

The sodium channels open and rushing in to reach the threshold

Question 15

what is the all or none effect

Answer 15

Refers to the action potential
If the threshold is reached the action potential will occur and travel down the whole axon-domino effect
If the threshold is not reached no impulse will happen and it will stop

Question 16

what is a reflex arc

Answer 16

Reflex arc is the pattern that happens when a reflex occurs in the body.
Pathway:
Stimulus
Receptors of the skin
Sensory neuron brings it to the interneuron of the spinal cord
May or may not have an interneuron depending on the pathway
Reaches the effector (knee jerk=muscles-quads and hamstring but usually a muscle or gland) by the motor neuron

Question 17

sympathetic division

Answer 17

Fight or flight response

Heart beats faster, digestion is inhibited, liver converts glycogen to glucose, secretion of epinephrine

Question 18

parasympathetic division

Answer 18

Rest and digest response

Lowers heart rate, enhances digestion, increases glycogen production

Question 19

sclera

Answer 19

tough white outer layer of connective tissue

Question 20

choroid

Answer 20

a thin, pigmented inner layer

Question 21

cornea

Answer 21

the transparent frontal portion of the sclera, which allows light to enter into the vertebrate eye, protection

Question 22

retina

Answer 22

forms the innermost layer of the eyeball and contains layers of neurons and photoreceptors

Question 23

lens

Answer 23

the structure in an eye that focuses light rays onto the photoreceptors, disk shaped that can get wider or thinner depending on what you are looking at, regulating the ciliary bodies, focuses light rays on the retina

Question 24

cilia body/suspensory ligaments

Answer 24

a portion of the vertebrate eye associated with the lens. It produces the clear, watery aqueous humor that fills the anterior cavity of the eye. Expands and contracts the size of the lens

Question 25

aqueous humor

Answer 25

fills the anterior cavity

Question 26

vitreous humor

Answer 26

constitutes most of the volume of the eye

Question 27

pupil

Answer 27

where light enters, a hole that is regulated by the iris, regulates amount of light in

Question 28

iris

Answer 28

contracts or expands, changing the diameter of the pupil to let in more or less light, controls the pupil

Question 29

fovea centralis

Answer 29

best vision area of your retina

Question 30

optic nerve

Answer 30

blind spot right in front of the optic nerve

Transfers visual information to the brain

Question 31

blind spot

Answer 31

underneath the fovea centralis

Question 32

What is the function of Ca+2 in muscle contraction

Answer 32

Motor neurons cause muscle contraction by triggering release of Ca+2 into the cytosol of muscle cells with which they form synapses
Allows the myosin head to bind during the muscle contraction
Without the calcium there is no muscle contraction