A&P for mice and rats

Question 1

rats and mice have tails that are longer than their body length

Answer 1

true

Question 2

rats have a gallbladder

Answer 2

false

Question 3

the inguinal canal in males remains open throughout life

Answer 3

true

Question 4

mice and rats typically breed during daylight hours

Answer 4

false

Question 5

secretions from the harderian gland in rats is commonly called

Answer 5

red tears

Question 6

what is brown fat commonly called and where is it located?

Answer 6

hibernation tissue and it is located diffusely around the neck and between the scapulae

Question 7

how much does the hibernation tissue provides energy storage than other types of fat?

Answer 7

10 times

Question 8

Gestation for mice/rats

Answer 8

mice: 19-21 days
rats: 21-23 days

Question 9

when do mice reach puberty? when do rats reach puberty

Answer 9

mice: 35 to 50-60 days
rats: females- 37 to 67 days
males- 40-75 days

Question 10

what is the average lifespan of mice and rats?

Answer 10

mice: 1-3 years
rats: 2-4 years

Question 11

normal TPR for mice?

Answer 11

98.6F, HR: 427-697bpm, RR: 91-216bpm

Question 12

normal TPR for rats?

Answer 12

98.6F, HR: 313-493bpm, RR: 71-146bpm

Question 13

how many digits do rats and mice have on the forelimbs and hind limbs?

Answer 13

4 digits in the forelimbs and 5 digits in the hindlimbs

Question 14

how many pairs of mammary glands do female rats have and where are they found?

Answer 14

4-6 pairs and found in the thoracic and inguinal areas

Question 15

how many pairs of mammary glands do female mice have and where are they found?

Answer 15

5 pairs and extend to the sides and back

Question 16

do male mice have mammary glands?

Answer 16

yes

Question 17

the uterus of mice and rats is considered

Answer 17

bicornuate

Question 18

what do each uterine horn have seperately

Answer 18

cervical canal

Question 19

what type of ovulators are mice and rats? what type of estrus cycle do they have? How long does their estrous period last?

Answer 19

spontaneous ovulators. they are continously polyestrus and it lasts 4-5 days

Question 20

in mice and rats the postpartum estrus occurs when?

Answer 20

20-24 hours after parturition

Question 21

the presence of a copulatory plug can be used to confirm

Answer 21

mating

Question 22

what type of teeth do mice and rats have?

Answer 22

hysodontic

Question 23

the direct result of mating between two different inbred strains

Answer 23

hybrid

Question 23

develop as a result of genetic mutation in existing strains. The mutation is then carried on in future generations

Answer 23

coisogenic

Question 24

strains are those in which a mutation that arises in one strain is transferred to another strain through a series of backcross mating. this is how nude animals were developed.

Answer 24

congenic

Question 25

a mouse whos DNA has been modified so that is does not express particular proteins

Answer 25

stock

Question 26

why do rats have the inability to vomit

Answer 26

the gastroesophageal barrier

Question 27

describe the unique structures of the rats lungs

Answer 27

left side is small and singular while the right side is larger and divided into 4 sections

Question 28

what is chromodacryorrhea? When does it commonly occur?

Answer 28

It is red tears which are known as bloody tears. It occurs when the animal is stressed

Question 29

what is the purpose of tails in mice and rats?

Answer 29

it functions as balance and a mechanism for heat loss

Question 30

describe the pancreas in rats

Answer 30

diffuse, has a lot of ducts that empty into the intestines

Question 31

what is a copulatory plug, and how long does it remain in place?

Answer 31

it is a plug that is dried semen mixed with secretions from the vagina and confirms mating It remains in place for 12-24 hours after mating

Question 32

what is an intestive breeding program for mice and rats?

Answer 32

continuous housing of the male and females

Question 33

what is a non-intensive breeding program for mice and rats

Answer 33

seperate housing the male and female while the female is pregnant

Question 34

what is the bruce effect?

Answer 34

a pregnant mouse who is exposed to a new male within 4 days of breeding, the pregnancy will be aborted

Question 35

what is the whitten effect?

Answer 35

when females are exposed to a male or the odor of a male. they will begin estrus within 3 days

Question 36

what is a stock breed animal?

Answer 36

type of mouse/rat that has been randomly bred. Not imbred

Question 37

when is an inbred animal considered a strain?

Answer 37

at least 20 generations of brother-sister or parent have mated

Question 38

what are 5 ways to ensure genetic purity in inbred mice?

Answer 38

protein electrophoresis, serologic testing, mandible measurements, backcross mating, and tissue transplants

Question 39

what is a transgenic animal?

Answer 39

when a animal carries a foreign gene that has been deliberately inserted into ints genome

Question 40

why do we use so many mice and rats in animal research?

Answer 40

they have a well characterized genetic make-up