canine/feline test 1 review

Question 1

The origin of dogs and cats and how they have evolved into our present-day companions?

Answer 1

-over 40 million years ago with the
development of Miacis 細齒獸
-Thomarctus - protoype dog原型狗
* 12000 BC, dogs treat as a hunting companion
* bronze age (3500 BC), dog see as guard
animals
* 600 BC-> herders of livestock,
particularly sheep
* Egyptian rule they were being kept as
pets

The four prototype breeds
Canis familiaris metris-optimae
* forerunner of sheep-herding breeds
Canis familiaris intermedius
* forerunner of many hauling, hunting, and toy breeds
Canis familiaris leineri
* forerunner of the sighthound and many terriers
Canis familiaris inostranzewi
* forerunner of mastiffs and some water dogs

Due to selective breeding our
present day dogs differ from
these wild prototypes
* Many wild canids are
monogamous一夫一妻, which is not true
for today’s dog
* In the wild sexual maturity
often does not occur before two
years. However, domestic dogs
reach puberty at six to eight
months of age.
* Wild dogs only produce one
litter per year, where as
domestic dogs can produce 2
even 3 litters per year

Question 2

inbreeding

Answer 2

Inbreeding
The breeding of closely
related progeny (son to
mother, half-brother to half
sister, father to daughter) to
allow the strongest most
desirable traits to be fixed
* Also concentrates any
weaknesses
* Products of inbreeding can
be either much better or
much worse then the
parents
* Breed can be strengthened
by culling

Question 3

line breeding

Answer 3

The breeding of individuals that are more distantly
related, but with common ancestors in their pedigree
for four or five generations
* Allows for establishment of certain families or
strains with similar characteristics
* Doesn’t stabilize characteristics as efficiently as
proper inbreeding

Question 4

outcross breeding

Answer 4

Outcross Breeding
The breeding of individuals with no common ancestors in the last
four or five generations
* Used to bring hybrid vigor & minimize undesirable characteristics
* Lacks uniformity in the offspring
* Parents are often products of line-breeding chosen to compliment each other
* Hopefully this means the shortfall of one parent is balanced by the strength of
the other

Question 5

What are the 8 group of dog breeds?

Answer 5

The eight groups are: Sporting Dogs, Hounds, Working Dogs, Terriers, Toy Dogs, Non-Sporting Dogs, Herding Dogs and Miscellaneous and Rare Breeds Group.

Question 6

Sporting dogs

Answer 6

• High energy dogs with great stamina
• Have great noses
• Show a desire to retrieve, point and flush out
• Can be divided into four sub-categories: Setters, Spaniels, Retrievers, and Pointers
• Spaniels tend to be smaller in size than the rest
• Spaniels and Setters require some coat care
• Very active which may lead to destructive
  tendencies if not given enough exercise

Question 7

Hounds

Answer 7

• Independent nature, therefore they
  require good fencing to prevent roaming漫游
• Can be divided into sight hounds and scent hounds (trail
  hounds)
• Trail hounds have a superior sense of smell with the
  sight hounds a close second
• Some are bred to hunt in packs
• Sight hounds are known to run full out at top speeds
• Trail hounds are diligent & patient, but can be
  destructive
• Sometimes difficult to housebreak and are given to
  howling

Afghan Hound, basenji 巴辛吉（一種小猎犬), Basset Hound (法国原产的短腿猎犬,有點似猎腸狗), Beagle, Bloodhound (眼皮和面皮都跌晒落黎), Borzoi (大隻白色長毛九尾狐), Dachshund 德國猎腸狗超短腿，Greyhound, Irish Wolfhound (超大雙的似史立莎狗), Norwegian Elkhound (似北歐淺灰色狼狗), Rhodesian Ridgeback (大隻麻甩佬啡色狗), Saluki (優雅長咀長毛大狗), Whippet (雜色灰狗)

Question 8

working dogs

Answer 8

• Possess great intelligence and devotion to their
  owners
• Watchdogs, pull/cart/pack, guard livestock, and for
  rescue
• Lower activity level, but size & guarding instinct
  must be considered

Akita 秋田犬, Alaskan Malamute, Bernese Mountain Dog 伯恩山犬, Boxer, Bull Mastiff (大型bulldog), Doberman Pinscher 都栢文, Great Dane (超大型麻甩樣灰啡斑點), Mastiff 獒犬, Newfoundland (毛卷而厚似羊毛), Rottweiler, St. Bernard (雪山狗蠢蠢樣超厚毛), Samoyed (明姨隻狗), Giant & Standard Schnauzer, Siberian Husky, Neapolitan Mastiff (松皮大型老虎狗)

Question 9

Terriers 梗类犬

Answer 9

• Feisty, independent, stubborn, and may be
  aggressive to other dogs
• Devoted, cheerful pets
• Bred to eliminate vermin
• Divided into three sub-groups: long
  legged, short legged, and at one time
  fighting dogs
• Great at digging
• Fear nothing
• Possess the desire to follow vermin
• Barking may be a problem

Airedale (少似史立莎長尾黑斑), American Staffordshire Terrier (細隻boxer), Bull Terrier (無鼻涼細眼狗), Cairn Terrier (中長毛細狗), Fox Terrier （分wired 和smooth）, Miniature Schnauzer (迷你史立莎), Scottish Terrier (黑色terrier), Soft Coated Wheaten Terrier （超長毛蠢蠢樣）,West Highland White Terrier （狗糧牌子隻狗）,

Question 10

Toy Breeds

Answer 10

• Many are nobility from centuries ago
• “lot of dog in a small package”
• Many are miniatures of larger breeds
• Divided into different sub-groups: Sight hounds,
  Molloser-type dogs, Spaniels, Spits, Terriers, Pinschers
• May present housebreaking problems
• Not recommended for homes with rowdy kids
• Great for small spaces

Chihuahua, Maltese (超長毛頭上扎鞭), Pekingese （北京狗似西施又不是西施）,Pomeranian (超小松獅咁), Toy Poodle, Pug(八哥hunter), Yorkshire Terrier (超長毛有須的札鞭女仔樣)

Question 11

Non-Sporting
Breeds

Answer 11

Catch all group
Difficult to
categorize

-Bichon Frise(家姐隻truffle)，Shih Tzu，Boston Terrier （好似法國鬥牛犬）,Shar-pei, Chow Chow (松獅犬), Dalmation (班點狗), Keeshond 獅毛狗small, Llasa apso (毛長到遮住左個樣)

Question 12

Herding Dogs

Answer 12

• Very intelligent, large capacity beyond tending livestock
• Good natural watchdog
• Well rounded pet
• Sub-divided into herders and drovers
• Herders tend to flock & drovers drive them to market
• Developed to work with a variety of livestock
• Form strong family attachments
• Not usually prone to roam
• Very popular for companion dogs

Australian Cattle Dog 牧牛犬細隻雜色, Australian Shepherd，Bouvier des Flandres （大隻狗糧牌子狗長毛）, Collie 邊牧, German Shepherd Dog, Old English Sheepdog (大型遮眼毛狗), Pembroke Welsh Corg 哥基, Cardigan Welsh Corgi (比哥基隻腳更短), Schapendoes (Dutch Sheepdog (長卷毛流浪漢咁樣狗)

Question 13

Miscellaneous
Class

Answer 13

• Breeds not well known outside their own area
• Will only be awarded full recognition when the breed is
  well established with sufficient numbers
• Once breed more well known may be put into one of the
  other groupings
• No cross breeds

top group: Coton de Tulear
Border Collie
Group: Herding
Catahoula Leopard Dog
JRT Jack Russel Terrier

Question 14

ORIGIN OF THE DOMESTIC
CAT

Answer 14

• PANTHERA豹属: “the great cats” which
  include; tigers, lions, leopards, and jaguars
• ACINONYX 猎豹: the cheetahs 印度豹
• FELIX: pumas, cougars, and the domestic
  cat “Felis catus”

1600 BC in Egypt
thousands of years
after the dog

Egyptian farmers began the domestication process knowing their value as pest controllers

Excellent night vision, From Egypt Onward, Middle east, India, and China were next
*Romans introduced cats to Europe
*Cats traveled on ships for pest control, and from there went world wide
*Today cats are the most popular house pet

Question 15

Cat’s breed development

Answer 15

Natural Breed
* A natural breed is based upon a naturally
occurring population of cats from a specific
geographical area
* Continuation of a pure natural breed can only
occur from matings within the breed

Established Breed
* The mating of two different natural breeds
originally, but now continued only through
matings within the breed

Hybrid Breed
* Originally established through the mating of
two different natural breeds.
* Back-crossing to one or both of the original
breeds is allowed

Mutation
* A sudden change in genotype that has no
relation to the individual’s ancestry. They
can be passed on to subsequent generations,
and back-crossing is allowed.

Mixed Breed
* A mixed breed resulting from the random matings
of various cat breeds or other mixed-breed cats.
They rarely resemble the standard for any breed.
* 90% of cats today fall in this category, and are
healthy & hardy

Question 16

What are the cat body types

Answer 16

Cobby (長厚毛和短身矮), semi-cobby (無咁長毛和比cobby長少少), foreign (長身長尾), semi-foreign (長至中身), oriental （瘦長身型）, long and substantial （中大型貓，骨重和長身）

Question 17

What are cat head types?

Answer 17

Round
* Wide, round head with broad skull, round ears set
low in head

MODIFIED WEDGE
* Head medium length and width, slightly
broader at the top and tapering to a rounded
triangle at the muzzle

WEDGE
* Face narrowing in straight lines from the base of
the ears to the muzzle, forming a perfect wedge.
Profile straight with no break in the nose.

Question 18

what are the breeds?

Answer 18

Abyssinian (瘦啡家貓)
American Shorthair (圓頭圓眼)
Burmese (黑色瘦modified wedge臉)
Manx (有點似ASH但無尾)
Ocicat (圓至尖頭尖耳冷漠樣)
Persian (卡菲貓)
Siamese （尖面異域貓長尾）
American Curl (圓頭圓耳長尾)
Himalayan (淺藍眼白色長毛垂耳)
Ragdoll (藍眼白色長毛壹耳)
Maine Coon (普通家貓但狐狸厚尾巴)
Russian Blue (淺灰色短毛長尾貴貓)
Scottish Fold (肥頸垂耳圓圓眼小型貓)
Tonkinese (白瘦長尾尖面壹耳貓)
Turkish Angora (九尾狐轉世貓)

Question 19

What is pedigrees族譜?

Answer 19

Parental Lines: The first generation (original parents) in a “family tree”
* F1 generation: Offspring of the Parental Line
* F2 generation: Offspring of the F1 generation (grandchildren of the parental line)
* Crosses: The result of these matings

Parent male is polydactyl 多指症(square is solid)
o Neither of his two daughters (F1) have polydactyly (circles are not filled)
o In the F2 generation:
o Two of the offspring are polydactyly (solid)
o The remainder of the offspring do no exhibit polydactyly

Question 20

What are alleles 等位基因？

Answer 20

 Allele refers to the various forms a particular gene can
take.

A dog inherits two alleles for each gene, one from each parent. If the two alleles are the same, the dog is said to be homozygous. If the alleles are different, the dog is deemed heterozygous.

 In the polydactyly example given previously, the
characteristic (like all inherited characteristics) is
controlled by a gene. This gene may be normal (correct number of fingers) or defective (causing
polydactyly). The two forms this gene can take are alleles. In this case, there are two alleles of the gene.

 In biochemical terms, an allele is a section of DNA on a
chromosome that codes for a particular protein. For
almost every characteristic, all animals have two
alleles. These may be the same, or different.

Question 21

GENOTYPE 基因型 VS PHENOTYPE 表型

Answer 21

• The outward appearance of a person, animal or plant is called its phenotype.
• The true genetic makeup (the nature of its alleles) is called its genotype.
   Pedigrees show only phenotype. They do not indicate the presence of an unseen, abnormal allele.

 This can be explained by the principles of dominant and recessive genes.
* Dominant alleles always determine phenotype, even when paired with a recessive allele
* To reveal a recessive phenotype, both alleles must be recessive
 In a pedigree using letters, dominant alleles are represented by capital letters and recessive alleles by
lower case letters

Question 22

HOMOZYGOUS VS HETEROZYGOUS

Answer 22

 Describes whether an individual animal has two alleles that are the same, or two alleles
that are different for a given characteristic.
* An individual with the genotype CC or cc is homozygous for the characteristic
o Their two alleles are identical
* An individual with the genotype Cc is heterozygous for the characteristic
 Individuals that are homozygous for a given trait breed true. This means that mating two
individuals with that genotype will produce offspring all of a single genotype and
phenotype.
 Heterozygous individuals, on the other hand, do not breed true: a cross between two
heterozygous individuals (Aa x Aa) may produce offspring with AA, Aa or aa genotypes.

Question 23

CARRIERS

Answer 23

-Heterozygous individuals are sometimes called carriers, because they carry a recessive
gene that can be passed on to their offspring but individually do not show the
characteristic.
 The trait may show up again in future generations descending from the carrier.

Question 24

TEST CROSSES

Answer 24

 Individuals with the genotype Cc will appear (physically) the same as an individual with the
genotype CC because C is a dominant allele.
 Sometimes, a breeder wishes to know whether an individual is a homozygote (CC) or a
heterozygote (Cc). Since the phenotypes are the same, there is no way of telling by looking at
the animal.
 The breeder must perform a test cross. The purpose of such a mating is to determine the
genotype of one of the parents.
 To perform a test cross, the individual of unknown genotype is crossed with an individual who is
homozygous recessive.

Question 25

HYBRIDS

Answer 25

 An individual that is the offspring of a cross
between two purebred animals, but whose parents
belong to different breeds or species, is called a
hybrid.
 The advantage is that the hybrid offspring appear
to be healthier and more disease resistant than
either of the parent lines. The hybrid exhibits the
best characteristics of each allele. This
phenomenon is called hybrid vigour or heterosis.
 Depending on breed, purebred dogs are often
subject to many diseases.
 Fortunately, most of these disease-causing genes
are recessive; therefore, if one breed is mated to a
different breed that carries the dominant, normal
gene, the offspring are unlikely to exhibit any of
these diseases. They have hybrid vigour.
 This is assuming both parent dogs do not share
the same defective genes.
 It is possible that the phenomenon of hybrid vigour
explains why mutts tend to have a lower incidence
of genetic diseases than purebred dogs, no matter
the breed.

Question 26

INDEPENDENT
ASSORTMENT

Answer 26

 The inheritance of each characteristic is a separate event
(characteristics are not inherited together).
 In animal terms, this could be illustrated by the mating of two
dogs:
* Dog 1 has a genetic defect for blindness and a black coat
colour
* Dog 2 has normal vision and a white coat colour
* Offspring will inherit their parent’s genes for coat colour and the
genes for vision; however, the two are inherited separately
o Inheriting normal vision does not mean the dog will inherit
a white coat colour
o This makes sense since these genes may be on different
chromosomes
 The only exception to this type of inheritance occurs when the
genes for two characteristics are found on the same
chromosome. If this happens, they will be passed on together,
and are said to be linked.

Question 27

PUNNETT SQUARE

Answer 27

 The Punnett square is useful in determining the possible outcomes of a cross involving more
than one characteristic (A and B on separate genes).
Although phenotypes can be known visually, unless test
crosses are performed dominant genotypes based on
pedigree analysis are merely well-educated guesses.

Question 28

TYPES OF DOMINANCE

Answer 28

incomplete dominance, co-dominance and complete dominance. Incomplete dominance occurs when there is a relationship between the two versions of a gene, and neither is dominant over the other so they mutate to form a third phenotype.Jun 16, 2022

 For many characteristics, an animal that is
heterozygous (Bb) does not appear identical to the
homozygote (BB); rather, it appears as mainly B with
a bit of b.
 Therefore, a dog that was Bb might appear mainly
black with a few white hairs.
This type of gene interaction is called incomplete
dominance. The dominant trait does not completely
mask the recessive trait.

 For any set of alleles (B, b, etc), only one form of dominance will be seen:
• Complete dominance
• Incomplete dominance
• Co-dominance

Question 29

EPISTASIS异位显性

Answer 29

what happens at one gene can mask what’s happening at another gene. Because of epistasis, it’s rare to see those masked genes actually expressed in a dog’s coat color.

Epistasis occurs when the expression of one gene is affected by the expression of one or more independently inherited genes. One example is how white coat colour is regulated: white fur in cats is epistatic over all other coat colours.

Question 30

X AND Y CHROMOSOMES

Answer 30

Every dog has two sex chromosomes, females have two X chromosomes and males have an X chromosome and a Y chromosome.

Since the distribution of the X and Y chromosome varies with the sex of the individual
(they are either XX or XY), inheritance of the genes found on the X and Y chromosomes
will also vary with the sex of the individual.
 All females have two X chromosomes and characteristics that are determined by genes
on the X chromosomes are called sex-linked characteristics.

Question 31

SEX-LIMITED INHERITANCE

Answer 31

Sex-limited traits are those characteristics expressed only by one sex, such as milk production, egg
production, and semen production.
 These characteristics, like all inherited characteristics, are controlled by genes.

Governing hormones such as estrogen and
testosterone
o If estrogen is present, female characteristics will
develop (mammary development, milk
production)
o If testosterone is present, male characteristics
will develop (beard growth in humans)控制激素，如雌激素和
睾酮

Question 32

LETHAL AND DETRIMENTAL genes 致命和有害的

Answer 32

 It is evident that some genes inherited on either the sex chromosomes or the autosomes may
be defective and result in disease.
 In many cases, the defective gene; a heterozygous individual (Mm) will be a carrier but will
not show signs of disease.
 In some cases, the defective genes are detrimental to the normal function of the individual
that the homozygous form (mm) is not compatible with life. These genes are called lethal
genes.
 When a recessive lethal gene is present in both parents, probability suggests that 25% of
offspring will die before or soon after birth. In fact, the gene is considered lethal if the
individual dies before reaching reproductive maturity.

Question 33

Selective breeding

Answer 33

he idea of selective breeding is simple: the animal’s owner (farmer or breeder) wishes to achieve
the best quality offspring from each mating and selects the animal’s mate on that basis.
 The selection of an animal’s mate based on the genotype of each animal is called artificial selection.
 This differs from natural selection in which an animal chooses its own mate, presumably at random

Question 34

LEVEL OF HERITABILITy

Answer 34

 Traits can be described by their level of heritability:
* Collie eye syndrome is highly subject to genetic selection; it has high heritability
* Hip dysplasia is somewhat subject to genetic selection; it has medium heritability

 Traits that have high heritability tend to have the following characteristics:
* Controlled by only one or two genes
* Sharp distinction between phenotypes (animal is either normal or abnormal)
* Qualitative (black versus white)
* Defects or diseases are obvious
* Little environmental influence on phenotype; all animals with the gene show the same
characteristics, regardless of environment
* Example of a trait with high heritability would include:
o Hip dysplasia in dogs

 Traits that have low heritability tend to have the following characteristics:
* Controlled by many genes
* No sharp distinction between phenotypes (degree of trait expressed may vary greatly)
* Quantitative (measured in terms of numbers)
* Some environmental influence on phenotype; genes alone do not determine appearance
* Example of a trait with low heritability include:
o Growth rate in dogs

Question 35

REAL LIFE GENTICS

Answer 35

. Most characteristics (height, personality, etc) are controlled by more than one gene.
* Any one gene may have five or ten different alleles.
* Examples given thus far illustrate the simplest inheritance; one gene controls one
characteristic. This pattern holds true for some diseases and genetic disorders (hemophilia
in humans) but is too simplistic to explain most inherited traits.

Question 36

MUTATIONS

Answer 36

 A mutation is a change in DNA structure
which may be present in a single cell or in
every cell of the body.

 Some mutations are very large and may involve many genes:
* A piece of chromosome may break off and be lost from the
cell
o All proteins coded by the lost genes cannot be manufactured by
the cell or its progeny
 Mutations usually arise because the DNA has been altered by
an accidental exposure to a mutagen; any material or energy
form that can cause a mutation can act as a mutagen.
Examples of mutagens include:

Question 37

DNA TESTING

Answer 37

 Large, state-of-the-art DNA diagnostic laboratories are designed
and equipped for development and implementation of diagnostic
tests based on the analysis of nucleic acid, the genetic blueprint for
all living organisms.

Question 38

COLLECTION
METHODS

Answer 38

Buccal Swab Sample Collection: The
collection of epithelial cells from the lining
of the cheek using a swab technique
should not be used on dogs under 6 weeks
of age.

 Blood Sample Collection: Cause a
small amount of bleeding by
trimming the dog’s nail short or
by pricking the paw pad with a
sterile needle. Collect the blood
by tapping the indicated corners
of the blood card the bleeding
area. Fill the indicated corners as
wholly as possible. Allow the
blood sample to dry completely
for at least 30 min (depending on
saturation level) before placing in
plastic bag for transport to the
lab.

Dewclaw or Docked Tail Sample
Collection: After removal place the
dewclaw or tail in a paper envelope
(avoid plastic, as the sample could
grow bacteria or decay in plastic). You
must allow the sample to dry
completely prior to sealing the paper
envelope.

Question 39

PARENTAGE PROFILES

Answer 39

 The comparison between parents is done by a cross-match of DNA. Each offspring receives two copies,
called alleles, one from each parent in a random process. The offspring’s genetic phenotype depends on
the combination of dominance and/or recessive traits that it receives.
 The probability of recessive gene inheritance escalates as the number of combinations of traits increases
(ie, coat colour combined with texture and length). For this reason, scientists do not use the actual genes
to generate DNA profiles, but rather use DNA sequences called markers.
 A marker is a gene or DNA sequence with a known location on a chromosome used to identify an
individual or species. These markers are inherited in the same manner as genes.