Genetics and Neonatal Care

Question 1

Monohybrid Cross

Answer 1

Two individuals that differ for a single trait
* 1 dominant and 1 recessive gene each

Question 2

Dihybrid Cross

Answer 2

Two individuals that differ for two traits
* 2 dominant and 2 recessive genes for each

Question 3

Inheritance Patterns

Answer 3

Based on location of gene and whether is it dominant or recessive
* sex-linked = genes located on sex chromosomes X and Y
* autosomal = all other genes

Question 4

X-Linked Recessive
Carrier Females

Answer 4

• Gene on X-linked chromosome
• Carrier females = unaffected
• Sons from carrier females have 1:1 chance of expressing
• Affected males will pass on to all daughters, never to sons
• Unaffected males never transmit
• ex: colorblindness

Question 5

X-Linked Recessive
Males vs Females

Answer 5

• Males with X-linked recessive gene will always express it
• Females need to be homozygous for X-linked recessive gene to express

Question 6

Backcross
Breeding

Answer 6

• F1 = offspring bred from two purebred parents
• Backcross = F1 bred to one with identical genes as parent
• No relation

Question 7

Outbreeding

Answer 7

• Also called random breeding
• Helps keep gene pool as large as possible
• Breeding done between unrelated individuals

Question 8

Assortative Breeding

Answer 8

• Breeding of those with similar genes
• Specific gene characteristics are chosen to help pass on to offspring

Question 9

Inbreeding

Answer 9

• Breeding of closely related individuals
• Increases similarities in offspring
• Produced after 20 or more consecutive inbred matings
• Chance to express lethal genes
• Inbred depression = more poor genes begin showing

Question 10

Line Breeding

Answer 10

System of inbreeding to guarantee similar traits in offspring
* genes chosen from one or more exceptional members of the line to pass on

Question 11

Transgenic Strains

Answer 11

Altering of the genetic makeup of a developing embryo

Question 12

Translocation

Answer 12

• Breakage of two chromosomes
• Repairs in abnormal arrangement

Question 13

Duplication

Answer 13

Allele is duplicated
* ex: Down syndrome

Question 14

Lethal Genes

Answer 14

Gene that will cause death of embryo, death after birth, or serious impairment
* semilethal = abnormal traits
* most are recessive genes

Question 15

Feline
Estrous / Gestation

Answer 15

• Seasonally polyestrous
• Induced ovulation
• Gestation = 63 days

Question 16

Canine
Estrous / Gestation

Answer 16

• Nonseasonal - no true cycle
• Estrus occurs twice per year
• Gestation = 63 days

Question 17

Estrous Cycle
Proestrus

Answer 17

• Vulva swollen with discharge
• Males attracted but not accepted by female
• Noncornified squamous epithelial cells

Question 18

Estrous Cycle
Estrus

Answer 18

• Clear discharge
• Females accept males
• Cornified squamous epithelial cells
• Ovulation 2-4 days after stage starts
• Metestrus occurs at the end, but no specific timing

Question 19

Estrous Cycle
Diestrus

Answer 19

• Males no longer accepted
• Abrupt decrease in cornified cells towards end of estrus - become noncornified

Question 20

Estrous Cycle
Anestrus

Answer 20

• Sexual inactivity between cycles
• Difficult to differentiate from diestrus via cytology

Question 21

Equine
Estrous / Gestation

Answer 21

• Seasonally polyestrous - spring to autumn
• Can induce estrous by increasing light exposure
• Gestation = 335 days or 11 months

Question 22

Equine
Pregnancy Determination

Answer 22

Transrectal Ultrasound

Question 23

Q Fever

Answer 23

• Caused by Coxiella burnetii (rickettsial organism)
• Causes abortions
• Zoonotic from infected material

Question 24

Bovine
Estrous / Gestation

Answer 24

• Nonseasonal Polyestrous 7-18 months
• Gestation = 278 days or 9 months

Question 25

Bovine
Pregnancy Determinations

Answer 25

Rectal palpation and ultrasound

Question 26

Bovine
Free Martin

Answer 26

Female twin of a male cafe
* infertile
* hermaphrodite

Question 27

Brucellosis

Answer 27

• Causes abortions, weak kids, mastitis in goats
• Caused by Brucella spp
• Zoonotic - causes Malta fever in humans
• Shed via body secretions

Question 28

Caprine
Estrous / Gestation

Answer 28

Goats
* seasonally polyestrous - fall and winter
* induced estrous with light manipulation
* gestation = 149 days

Question 29

Caprine
Estrous Cycle Control

Answer 29

• Buck effect - bring male with odor to female
• Prostaglandins = induce ovulation
• Progestins = delay ovulation

Question 30

Ovine
Estrous / Gestation

Answer 30

Sheep
* seasonally polyestrous - fall and winter
* can induce va light manipulation
* gestation = 145-155 days or 5 months

Question 31

Ovine
Estrous Control

Answer 31

• Whitten Effect - ram introduced just before breeding season to jump start cycle
• Flushing - increased dietary intake

Question 32

Porcine
Estrous / Gestation

Answer 32

Pigs
* nonseasonal polyestrous
* gestation = 114 days or 3 months, 3 weeks, 3 days