ALAT Breeding and Reproduction Questions and Answers 1 — Questions and Answers
Question 1: When determining the sex of neonatal mice, what is the most reliable anatomical comparison to make?
- The overall body size
- The visibility of nipples
- The anogenital distance (Correct answer)
- The length of the tail
Correct answer: The anogenital distance
The most reliable method for sexing neonatal rodents is to compare the anogenital distance, which is the space between the anus and the genital papilla. This distance is significantly longer in males than in females.
Question 2: A research colony manager wants to maintain maximum genetic diversity and vigor in a mouse colony. Which breeding scheme should be implemented?
- Inbreeding
- Backcrossing
- Test crossing
- Outbreeding (Correct answer)
Correct answer: Outbreeding
Outbreeding is the practice of mating unrelated or distantly related individuals. This strategy is used to maximize genetic variation (heterozygosity) and produce healthier, more vigorous animals, which is the opposite goal of inbreeding.
Question 3: An ALAT is caring for a pregnant doe (female rabbit). What is the typical gestation period the technician should expect for this animal?
- 19-22 days
- 30-33 days (Correct answer)
- 44-48 days
- 58-63 days
Correct answer: 30-33 days
The gestation period for the domestic rabbit (Oryctolagus cuniculus) is approximately 30 to 33 days. A period of 19-22 days is typical for mice, while 58-63 days is common for guinea pigs.
Question 4: Which of the following terms describes the period when a female animal is sexually receptive and will permit mating?
- Parturition
- Gestation
- Estrus (Correct answer)
- Anestrus
Correct answer: Estrus
Estrus, often referred to as 'heat,' is the specific phase in the reproductive cycle when a female is receptive to the male and ovulation occurs. Gestation is the period of pregnancy, parturition is the act of giving birth, and anestrus is a period of sexual inactivity.
Question 5: A technician is setting up breeding cages for mice using a polygynous system. Which of the following housing arrangements is correct for this system?
- One male housed with two or more females (Correct answer)
- One male and one female housed together as a pair
- Multiple males housed with a single female
- Multiple males and multiple females housed in a large group
Correct answer: One male housed with two or more females
A polygynous (a type of polygamous) mating system involves one male being mated with multiple females. This is a common and efficient method for rodent breeding in a laboratory setting. A monogamous system pairs one male with one female.
Question 6: What is the term for the process of separating young animals from their mother and transitioning them from a diet of milk to solid food?
- Weaning (Correct answer)
- Fostering
- Culling
- Gestation
Correct answer: Weaning
Weaning is the process of gradually introducing a young mammal to its adult diet while withdrawing the supply of its mother's milk. Fostering is transferring young to another mother, culling is removing animals from a colony, and gestation is the period of pregnancy.
ALAT Breeding and Reproduction Questions and Answers 1
When determining the sex of neonatal mice, what is the most reliable anatomical comparison to make?