genetics

Question 1

trait

Answer 1

an observable or measurable characteristic of an individual (coat color)

Question 1

animal production (how to make the trait shine)

Answer 1

breeding

Question 2

aim of animal breeding

Answer 2

get genetic change, improve traits,

Question 3

phenotype

Answer 3

an obsereved category or measured level of performance for a trait in an individual (red coat color)

Question 4

what makes a phenotype

Answer 4

genotype (the genetic makeup of an individual), enviornement (th effect external factors have on animal performance, must be suitable)

Question 5

how do we control phenotype

Answer 5

enviornement (through management and regional decisions) genotype (through animal breeding programs)

Question 6

heritability

Answer 6

the degree to which offspring resemble their parents in performance of a trait (the proportion of differences between offspring and parents)

Question 7

low, moderate, high

Answer 7

reproductive traites (number of offspring calving interval, fertility, 20% or less) growth traits (winging and yearling weight, 20-40%) carcass traits (rib eye, marbling, tenderness, 40% or greater)

Question 8

breeding value

Answer 8

the genetic worth or value of an individual as a parent (determined by how well the traits are passed onto siblings or kids)

Question 9

EPD (expected progeny differences)

Answer 9

a prediction of the difference between the performance of an individual’s progeny compared to all contemporaries for the progeny. compares one individual to another from the breed for a specific trait

Question 10

pure-breeding

Answer 10

mating individuals within the same breed (maintains bloodline and pedigrees)

Question 11

inbreeding

Answer 11

mating of close relatives

Question 12

line breeding

Answer 12

form of inbreeding used to concentrate genes of an outstanding ancestor without closeness of inbreeding

Question 13

grading or scaling up breeding

Answer 13

mating pure bred sires to commercial grade females

Question 14

cross breeding

Answer 14

mating animals from different breeds

Question 15

heterosis

Answer 15

superiority of an outbred individual related to the average performance of the parent populations

Question 16

menders laws of inheritance

Answer 16

the basics of classical genetics, mated pea plants, laid the ground work for all genetic and animal breeding theory developed since his time

Question 17

mitosis

Answer 17

two identical daughter cells, creates an exact copy of the parent cell, starts and ends with the same number of chromosomes (diploid)

Question 18

diploid

Answer 18

1 copy of mom and dad contribution, occurs in all cells of the body except ovaries and tesites

Question 19

phases of mitosis

Answer 19

prophase, prometaphase, metaphase, anaphase, telophase

Question 20

meiosis

Answer 20

type of cell division that occurs in the reproductive/ germ cells in ovaries/testies, leads to the formation of haploid cells (each cell has one of each homo chrome, enter mom or dads)

Question 21

meiosis 1

Answer 21

longer, extremely important, crossing over (a physical exchange of chrome pieces), reduction division, afterwards each daughter cell contains one pair of sister chromeatides, two haploids

Question 22

meiosis 2

Answer 22

equation division, cell division occurs again, no crossing over, chromosomes recondense, line up on the quivery plate, 4 haploids

Question 23

spermaid

Answer 23

mature into a haploid sperm cell

Question 24

divisions in oogenesis are

Answer 24

symmetric

Question 25

law of segregation

Answer 25

operation of paired genes during gamut formation (meiosis) (gametes contains half the number of chromosomes and genes as normal body somantic cells)

Question 26

law of independent assortment

Answer 26

the independent segregation of genes, all combos are possible

Question 27

linkage

Answer 27

Recombination is much less likely for loci that
are very close together because the probability of
a break occurring between them is much less