rats and mice ap Flashcards
rats and mice have tails that are longer than their body length (T/F)
true
rats have a gallbladder (T/F)
false
the inguinal canal in males remains open throughout life (T/F)
true
mice and rats typically breed during daylight hours (T/F)
false
secretions from the harderian gland in rats is commonly called _____
red tears
brown fat, commonly called _____ is located around the ____, and ____. it provides roughly __ times the energy storage as other fats
hibernation tissue, neck, scapulae, 10
gestation for mice is _____ days and ____ days for rats
19-21, 21-23
mice reach puberty at __ weeks and rats at ____ weeks
5, 5-9
the average lifespan of mice is ____ and ___ for rats
1-3, 2-3
the normal TPR for mice
T - 98.6, P - 427 - 697, R - 91 - 146
the normal TPR for rats
T - 98.6, P - 313 - 493, R - 71 - 146
rats and mice have __ digits on the forelimbs, and ___ digits on the hindlimbs
4,5
female rats have ___ pairs of mammary glands, they are found in the ____ and ___ areas
4-6, thoracic, inguinal
female mice have ___ pairs of mammary glands, they extend to the ___ and ____
5, sides and back
male mice also have mammary glands but their nipples are
insignificant
the uterus of mice and rats is considered to be ____ and each uterine horn has a separate ______
bicornuate, cervical canal
female mice and rats are ______ ovulators, and they are considered ______ with their estrous period lasting ____ days
spontaneous, continuously polyestrous, 4-5 days
in mice and rats the postpartum estrus occurs roughly ___ hours after parturition
20-24
the presence of a copulatory plug can be used to confirm _____
breeding
mice and rats have ____ teeth
hypsodont
___ animals are the direct result of mating between two different inbred strains
hybrid
_____ strains develop as a result of genetic mutation in existing strains. the mutation is then carried on in future generations
coisogenic
___ strains are those in which a mutation that arises in one strain is transferred to another strain through a series of backcross mating. nude animals were developed
congenic
a ___ is a mouse whose DNA has been modified so that it does not express particular proteins
knockout mouse
why cant rats vomit
the limiting ridge separates the 2 portions of the stomach, covers the opening from the esophagus
unique structure of the rats lungs
divided unequally, left lobe is smaller and single, the right lobe is larger and divided into 4 sections
what is a copulatory plug and how long does it remain in place
when dried semen mixes with secretions from the vagina, 12-24 hours after mating
chromodacryorrhea is
normal red secretions of the eyes, commonly occurs when the animal is stressed
purpose of tails
organ of balance and helps with heat loss
rats pancreas
highly diffuse, located throughout the mesentery, many ducts that supple digestive enzymes to the small intestine
what is an intensive breeding program for mice and rats
continuous housing of male and female animals
what is a non intensive breeding program
separate housing for the males and females while pregnant
what is the bruce effect
when a prego mouse is exposed to a new male (odor) within 4 days of breeding, the existing pregnancy will be aborted and female returns to estrus
what is the whitten effect
when females are exposed to a male / odor, they will begin estrus within 3 days
what is a stock bred animal
a mouse/rat that has been randomly bred
when is an inbred animal considered a strain
when atleast 20 gens of parent offspring matings have occured
5 ways to ensure genetic purity
protein electrophoresis, serologic testing, mandible measurements, backcross mating, tissue transplants
what is a transgenic animal
an animal who has had some DNA removed from one strain and is inserted into an ovum after fertilization
why do we use mice and rats in research
they have a well characterized genetic makeup, and can be bred to be specifically susceptible to certain diseases
