2015 SENIOR GENETICS

Transcription

1 2015 SENIOR GENETICS EASY 4455 (easy) HIH1040-1/ES94-95 Q: What color is recessive to black and bay? A: Chestnut 4456 (easy) HIH1060-1/HS19/TH458-9/ES90 Q: If a gene has the ability to mask the genetic makeup of the other gene in the pair, it is said to be what? A: Dominant 4457 (easy) HIH Q: How many pairs of chromosomes do horses have? A: 32 pairs 4458 (easy) HIH Q: How are characteristics passed from parents to offspring? A: By genes (also accept chromosomes) 4459 (easy) HIH Q: If a chestnut is mated to a chestnut, what color or colors can be produced? A: Only chestnut (additional info -- chestnut is recessive to black) 4460 (easy) HIH Q: What is the dense center of a cell that contains the genetic material? A: Nucleus 4461 (easy) TH447/HIH Q: 2 part question: How many pairs of chromosomes are there in a horse & are these pairs always identical in nature? A: 32 pairs; not always identical 4462 (easy) HIH1060-1/HS19/TH458-9/ES90 Q: If a gene cannot mask the genetic makeup of the other gene in a pair, it is said to be what? A: Recessive 4463 (easy) HIH Q: How many chromosomes does the sperm of a stallion or an egg of a mare contain? A: (easy) TH458/HS20-21 Q: What does genotype mean? A: Genetic make up 4465 (easy) TH458/HS20 Q: What does phenotype mean? A: Outward appearance

2 4466 (easy) HIH Q: Are roan horses heterozygous or homozygous? A: Heterozygous (additional info -- like with white horses, homozygous roan horses die in utero) 4467 (easy) HIH Q: What is the study of how characteristics are passed from parents to offspring? A: Genetics 4468 (easy) HIH Q: What are the units of inheritance? A: Genes 4469 (easy) HIH Q: What do we need to be able to see chromosomes? A: Microscope 4470 (easy) HIH Q: What is the term used to describe the condition when a pair of genes are identical? A: Homozygous 4471 (easy) HIH Q: What is the sex genotype for a mare? A: XX 4472 (easy) HIH Q: If paired genes are not identical, they are called what? A: Heterozygous 4473 (easy) HIH1060-1/TH61 Q: How many chromosomes are responsible for the sex of a foal? A: Two (one pair) 4474 (easy) HIH Q: What is the sex genotype of a stallion? A: XY 4475 (easy) HIH Q: What do you call an abnormal condition that an animal possesses at birth? A: Congenital 4476 (easy) HIH Q: Explain congenital. A: An abnormal condition that an animal possesses at birth 4477 (easy) HIH Q: In the inheritance of sex in the horse, what are the chances for the foal to be male? A: 50-50

3 4478 (easy) TH459/HS19 Q: A gene that does not show up when it's paired with a dominant gene is said to be what? A: Recessive 4479 (easy) HS19/TH458 Q: Which of the following is the dominant coat color black or chestnut? A: Black 4480 (easy) TH482/HIH Q: Which color can cover up or mask colored areas of a horse? A: White 4481 (easy) HIH Q: What is the general term for the X & Y chromosomes? A: Sex chromosomes 4482 (easy) HIH Q: What color foal will a homozygous gray produce? A: Gray - no matter what color the other parent is MEDIUM 4483 (medium) TH511 Q: What sex-linked disease results in a deficiency of clotting factor VIII? A: Hemophilia A (also accept Hemophilia) 4484 (medium) HIH Q: Although a horse may have the genetic potential to be large, fast or intelligent, 30-50% of the trait is due to what? A: Environmental factors (such as feed, care, training & injuries - all of which can have an effect on the horse's overall quality) 4485 (medium) ADV335 Q: Define heredity. A: Passing of traits from parents to offspring 4486 (medium) TH57 Q: Is the curly coat of the American Bashkir Curly caused by a dominant or a recessive gene? A: Recessive

4 4487 (medium) HIH Q: In reference to coat color, what genes must a chestnut horse have? A: Two recessive extension genes OR ee (accept either) 4488 (medium) HIH1040-1/ES94,95 Name two genotypes of a black horse. EE, Ee, aaee, aaee 4489 (medium) HIH Q: Why are all dominant white horses heterozygous & not homozygous? A: Homozygous white fetuses die before birth 4490 (medium) HIH675-2 Q: Which Quarter Horse sire has been linked to the disorder HC (HERDA)? A: Poco Bueno 4491 (medium) TH462 Q: One pair of chromosomes is responsible for the sex of a foal. The chromosomes are designated as XX & XY. Which pair designates the stallion? A: XY 4492 (medium) ES87 Q: What is the common term for deoxyribonucleic acid? A: DNA 4493 (medium) ES87 Q: What does "diploid" mean? A: A pair of chromosomes 4494 (medium) TH Q: What is the difference between genotype & phenotype? A: Genotype is the genetic makeup, phenotype is the outward appearance 4495 (medium) TH482 Q: The perlino color is a double dilution of what color? A: Bay 4496 (medium) HIH Q: CID (Combined Immunodeficiency) is an inherited disease of which breed? A: Arabian or part Arab (accept either) 4497 (medium) TH81 Q: 2 part question: What color results from a single cream dilution of bay & what color results from a double cream dilution of bay? A: Single cream dilution buckskin; double cream dilution perlino 4498 (medium) TH Homozygous pairing of the dominant genes for what 2 coat colors cause early embryonic death of the fetus? White & roan

5 4499 (medium) DET6/HIH Q: What is an allele (ah-leel)? A: Gene pair 4500 (medium) HS19 Q: What is the term for normal (somatic) cell division? A: Mitosis 4501 (medium) HIH Q: Are the genes for coat color separate or combined with the gene loci for occurrence & pattern of white hairs on the body? A: Separate 4502 (medium) HIH Q: Where is the genetic material carried? A: In the nucleus in form of chromosomes (accept nucleus, chromosomes, or DNA) 4503 (medium) HIH Q: Are male or female horses primarily affected by genetic diseases that have an X-linked mode of inheritance? A: Male horses 4504 (medium) TH81 Q: Grulla is a dilution of what basic coat color? A: Black (dun dilution of black) 4505 (medium) HS20 Q: Name the two types of cell division. A: Mitosis & meiosis 4506 (medium) ES95 Q: What does the agouti gene do? A: Restricts the black pigmentation pattern to the points of the horse (mane, tail, lower leg, ear rims) 4507 (medium) ES95 Q: In reference to coat colors, what color modifier do the letters A/a represent? A: Agouti 4508 (medium) TH458/HS20 Q: If you breed a heterozygous black stallion to a heterozygous black mare, what percentage of the foals may be red? A: 25% 4509 (medium) HIH1020-1/es87 Genes are made up of complex molecules of what? A: DNA

6 4510 (medium) HIH Q: The cream gene is a partially dominant gene which does what when combined with other color genes A: Lightens/ dilutes the color 4511 (medium) HS19 Q: What is the term for sex cell division? A: Meiosis 4512 (medium) HIH Q: In what type of cells do chromosomes exist as singles, not pairs? A: Egg & sperm cells (also accept -- gametes, or haploid cells) 4513 (medium) HIH Q: Define nucleus. A: Dense center of a cell that contains the genetic material 4514 (medium) HIH Q: How do you diagnose HYPP? A: Genetic blood test OR by clinical signs & elevated blood potassium levels 4515 (medium) HIH Q: Which breed of horse carries the genetic disease HYPP? A: Quarter Horse 4516 (medium) HIH Q: What is inbreeding? A: Breeding closely related animals 4517 (medium) HIH Q: If a sperm carrying the X chromosome fertilizes the egg, what sex will the foal be? A: Female 4518 (medium) HS21 Q: How many chromosomes do mules & hinnies have? A: (medium) TH447 Q: Who was the first to work out how genetic material is transmitted from one generation to the next? A: Gregor Mendel 4520 (medium) TH462 Q: Which chromosome carries the genes for most sex-linked traits? A: X 4521 (medium) TH462 Q: Give an example of a sex-linked trait. A: Hemophilia

7 4522 (medium) ES94 Q: What 2 base colors are determined by the extension gene? A: Black & red (chestnut) 4523 (medium) TH50 Q: Palomino is a single cream dilution of what color? A: Chestnut 4524 (medium) TH50 Q: A double cream dilution of chestnut results in what color? A: Cremello 4525 (medium) TH81 Q: What does dilution of color mean? A: Lessening the intensity 4526 (medium) TH81 Q: Cremello results from a double dilution of which base color? A: Chestnut 4527 (medium) TH81 Q: What color is a cream dilution of bay? A: Buckskin 4528 (medium) FCH297 Q: HYPP is found in which Quarter Horse line? A: Impressive 4529 (medium) TH473 Q: Which one of the following modifications of black does NOT have black points: bay, seal brown, buckskin, dun, grulla, or perlino? A: Perlino 4530 (medium) HIH Q: On what chromosome do you find the gene for hemophilia? A: X 4531 (medium) TH81 Q: What color is a single cream dilution of chestnut? A: Palomino 4532 (medium) HIH Q: Which lethal genetic defect can result from mating 2 overo Paint horses? A: Lethal white foal syndrome (OLWS) 4533 (medium) HIH Q: What are loci? A: Specific locations of genes on a chromosome (singular is locus)

8 HARD 4534 (hard) TH481 Q: What is the pangare effect of color? A: Causes light areas of color on muzzle, over eyes, on flanks & inside the legs 4535 (hard) HIH151-1 Q. Justin Morgan was the foundation sire for the Morgan breed. His ability to pass his breed type on to his offspring regardless of the type of mare he was bred to would be referred to by what genetics term? A. Pre-potent 4536 (hard) HIH675-1 Q: Identify the following disease that primarily affects Quarter Horses: superficial & deep layers of the skin separate resulting in "stretchy" skin that's easily damaged or torn. A: HERDA (Hereditary Equine Regional Dermal Asthenia) OR HC (Hyperelastosis Cutis) 4537 (hard) HIH675-1 Q: This disease results in stretchy skin due to separation of the superficial & deep layers of the skin. What breed is affected by HERDA or HC? A: Quarter Horse 4538 (hard) HS20/ES88 Q: Explain how mitosis differs from meiosis. A: Mitosis is normal cell division where each daughter cell receives an identical copy of the original chromosome pairs; meiosis is sex cell division where each daughter cell only receives half of each chromosome pair (haploid number of chromosomes) 4539 (hard) ES94 Q: What is an extension gene as relates to color genetics A: The gene that regulates the color differences in black-pigmented horses & red-pigmented horses 4540 (hard) HIH Q: What does the term quantitative gene action mean? A: Trait is controlled by several gene pairs (hard) ADV335-2 Q: Define Heritability Estimate. A: The percentage of the horse s expressed trait that is due to genetics OR the probability of that trait being passed from one generation to the next 4542 (hard) HIH Q: What does the term "nicking" mean? A: When offspring has more superior qualities than expected by their pedigree 4543 (hard) HIH675-1 Q: HERDA or HC is an inherited disorder that causes what? A: Causes skin to be very stretchable, fragile & vulnerable to trauma

9 4544 (hard) ES85 Q: What is gene mapping? A: Determining & recording the identities & positions of genes 4545 (hard) H3-10 Q: What is a punnet square? A: Way of determining what percentage of offspring of a mating will have which genes of the parents 4546 (hard) TH51 Q: You are planning to breed your chestnut mare & would love her to produce a palomino foal. In order to guarantee a foal of this color, what color stallion should she be bred to? A: Cremello 4547 (hard) HIH Q: What genetic disease is associated with the frame overo pattern? A: Lethal white foal syndrome 4548 (hard) HIH1060-6/ES99 Q: Identify two of the four breeds of horses that are affected by the sex-linked disease Hemophilia A: Thoroughbred, Standardbred, Quarter Horse and Arabian 4549 (hard) TH486 Q: What is the expected ratio of roan to solid colored foals if a heterozygous roan stallion is bred to a heterozygous roan mare? A: 2 roan to one solid (50% would be roan, 25% would be solid & 25% homozygous roan fetus would die in utero) 4550 (hard) HIH1060-1/es94 Q: What is the name of the special procedure used to visualize or examine chromosomes under a microscope? A: Karyotyping 4551 (hard) DET118 Q: What is the proper name for a mature sex cell? A: Gamete 4552 (hard) ADV335/HIH Q: In genetics, what does the term partial dominance mean? A: A gene action resulting in an intermediate state between the 2 alleles (additional info a single dominant cream gene doesn t make a chestnut cremello) 4553 (hard) HIH Genetically, what is the difference between a buckskin & a dun? Buckskin is a cream dilution of bay & dun is a dun dilution of bay (hard) HIH Q: 2 part question: If a mare is a carrier for an X-linked genetic disease, what percent of her male foals will be affected with the disease and what percent of her female foals will be carriers? A: 50% males will be affected and 50% of females will be carriers

10 4555 (hard) TH490 Q: Name the color pattern on a Pinto horse whose genetic color code for dominant white is at the T locus. A: Tobiano 4556 (hard) HIH Q: Where is the location of the cytoplasm? A: Between the nucleus & the cell wall 4557 (hard) HIH Q: 2 part question: What gene is responsible for the roan color & what letters represent it? A: Roaning gene; R/r 4558 (hard) HIH1020 Q: What would be the difference in the offspring from a homozygous black stallion & a heterozygous black stallion when mated with a chestnut or brown mare? A: All the foals from the homozygous black stallion would be black. Half the foals from the heterozygous black stallion would be black & half would be chestnut (hard) HIH Q: What gene must be present to produce the color bay? A: Dominant agouti (additional info -- dominant agouti modification of black) 4560 (hard) HIH1060-5/335-3/ES99 Q: What term is used to describe the genetic disease characterized by the failure of the immune system to form? A: Combined Immunodeficiency (CID) OR Severe Combined Immunodeficiency (SCID) 4561 (hard) HIH Q: What causes foals with lethal white syndrome do die? A: Failure of nerves in the gastrointestinal tract to develop (ileocolonic aganglionosis) 4562 (hard) HIH Q: What is a chromosome? A: Long, thread-like structure in the nucleus of a cell that contains genetic material 4563 (hard) HS25 Q: The genetic material of the sperm cell is contained in which part of the cell? A: Head section 4564 (hard) FCH298/HIH Q: A horse with what genetic disease would benefit from a diet that is low in potassium? A: HYPP or Hyperkalemic Periodic Paralysis (also accept PIPP or Potassium Induced Periodic Paralysis) 4565 (hard) HIH Q: Give an example of partial or incomplete dominance where the dominant gene is not fully expressed. A: Cream dilution in a palomino

11 4566 (hard) ADV335/HIH Q: In genetics, what does the term "co-dominance" mean? A: When the 2 alleles are equally dominant ( additional info example: like some color genes or genes for straight/curly hair) 4567 (hard) HIH Q: When a number of genes are required to produce a trait, what type of gene action is this considered? A: Quantitative 4568 (hard) HIH Q: What is a genetic disease? A: One that's a result of a DNA mutation & can be passed on to offspring 4569 (hard) TH539 Q: What do you call the form of inbreeding that's aimed at trying to maintain a close relationship with a particular animal? A: Line breeding 4570 (hard) TH555 Q: 2 part question: What is a quantitative trait & give an example? A: Trait influenced by many genes; examples speed, cow sense, jumping ability, etc (hard) DET198 Q: What is outcrossing? A: Mating animals that are members of the same breed, but which show no relationship close up in the pedigree 4572 (hard) TH483 Q: The gene for what color is located at the G locus? A: Dominant gray (gray) BONUS 4573 (bonus) HIH Q: A horse's characteristics are due to 2 things. Name them. A: Heredity & environment 4574 (bonus) HS19/ES88 Q: Explain 3 steps of mitosis. A: 1) Chromosomes duplicate, 2) chromosomes line up in the middle of the cell, 3) chromosomes pull a part, 4) cells start to divide, 5) cell division completes with each daughter cell receiving a complete copy of the chromosomes

12 4575 (bonus) HIH Q: Genetically, name 3 ways a black coat color be modified. A: Dilutions such as cream or dun, spotting such as Overo or Tobiano, gray, roan, bay (agouti) 4576 (bonus) HIH1090 Q: Name 3 things that should be considered when selecting breeding stock. A: Conformation, breeding/pedigree, disposition, size, individual performance records, progeny records 4577 (bonus) TH51 Q: If a palomino mare were mated to a palomino stallion, what percentage of foals would be what color? A: 50% palomino, 25% cremello, & 25% chestnut 4578 (bonus) TH473 Q: Name 3 coat colors whose base color is black with a dilution, modification, white pattern, etc. A: Bay (agouti modification), seal brown (agouti modification) buckskin (single cream dilution of bay), perlino (double cream dilution of bay), dun (dun dilution of bay), grulla (dun dilution of black), gray (gray modification), smoky black (single cream dilution of black), smoky cream (double cream dilution of black), blue roan 4579 (bonus) HIH Q: Name 3 things other than genetic-makeup that may affect a horse's potential. A: Care, feeding, training, injuries 4580 (bonus) HIH Q: Define the 2 basic types of genetic action Qualitative - trait influenced by 1-3 pairs of genes A: Qualitative - trait influenced by 1-3 pairs of genes; Quantitative - trait influenced by a number of genes 4581 (bonus) HIH153 Q: Define 3 of the following terms: outcrossing, grading up, crossbreeding, inbreeding, & line-breeding. A: Outcrossing mating of animals from different families within the same breed; Grading up mating animal with unknown ancestry with registered animal; Crossbreeding mating registered animals of different breeds; Inbreeding mating of animals more closely related than average; Line-breeding selective breeding along a certain genetic line to perpetuate certain desirable qualities (bonus) TH458-59/HIH Q: In traits affected by qualitative gene action there are 3 primary types of gene action that affect the trait. Name them A: Dominance, co-dominance, partial dominance 4583 (bonus) HIH Q: Name 3 traits of horses that are influenced by many genes. A: Conformation, temperament, physical performance, size, muscularity, longevity

13 4584 (bonus) ADV335 Q: Name 3 genetic diseases in horses. A: SCID (Severe Combined Immunodeficiency Arabians), HYPP (Hyperkalemic Periodic Paralysis Quarter Horses) HERDA (Hereditary Equine Regional Dermal Asthenia (formerly called Hyperelastosis Cutis Quarter Horses), OLWS (Overo Lethal White Syndrome Paints), GBED (Glycogen Branching Enzyme Deficiency Quarter Horses & Paints), JEB (Junctional Epidermolysis Bullosa Belgians), CSNB (Congenital Stationary Night Blindness Appaloosas), ERU (Equine Recurrent Uveitis Appaloosas), Hemophilia A (sex-linked trait seen in males), RER (Recurrent Exertional Rhabdomyolysis Thoroughbreds), Roaring (Laryngeal Hemiplegia Thoroughbreds) Do not need to give the breed accept either acronym or scientific name 4585 (bonus) HS18 Q: Tell how many pairs of chromosomes each of the following farm animals has horses, cattle, goats A: Horses 32, cattle 30, goats - 30