Genetics

Question 1

Alleles

Answer 1

Different form of genes associated with particular characteristics

Question 2

Chromosomes

Answer 2

Hereditary units of an organism

Question 3

Locus

Answer 3

Particular point where a certain gene is found on a chromosome

Question 4

Homozygous

Answer 4

An individual with two of the same alleles on a homologous chromosome

Question 5

Hertrozygous (hybrid)

Answer 5

An individual with contrasting alleles for the same trait on a homologous chromosome

Question 6

Parental generation

Answer 6

The two original organism being crossed

Question 7

First filial generation

Answer 7

The first generation of offspring from

The parent

Question 8

Second filial generation

Answer 8

Generation of offspring arising from the first filial generation

Question 9

Law of Dominance

Answer 9

• pattern of heredity in which one gene of an alleluic pair is expressed
• this in the heterozygous condition, one allele of a gene may express itself and mask the presence of the other allele

Question 10

Dominant trait

Answer 10

The trait or allele that is expressed

Question 11

Recessive

Answer 11

The trait or allele that is present but is not expressed

Question 12

Progeny

Answer 12

Offspring

Question 13

Siblings

Answer 13

Brothers or sisters

Question 14

Punnett square

Answer 14

Used to represent genetic crosses

Question 15

Genotype

Answer 15

The genetic makeup of an organism based upon alleles

Question 16

Phenotype

Answer 16

The appearance of an organism

Question 17

Genes

Answer 17

Factors that control organism traits

-the part of the DNA molecule containing the genetic code

Question 18

Principle of segregation and recombination

Answer 18

When gametes are formed during meiosis there is a random segregation of homologous chromosomes

• crossing over
• as a result of fertilization alleles recombined as a consequence a new allylic gene culmination are likely to produce

Question 19

Law of independent assortment

Answer 19

If genes for two different traits are located on a different chromosomes, they are segregated randomly during meiosis and therefore may be inherited independently of each other

Question 20

Incomplete dominance

Answer 20

A case of contrasting alleles in which one one allele is only particular dominay over the other

• The dominant allele is particularly express when a recessive allele is present
• sometimes called blending inheritance

Question 21

Codominance

Answer 21

Case of contrast no alleles in which neither will dominate over the other
—alleles have an equal power

Question 22

Gene linkage

Answer 22

Genes for two different traits are located on the same pair of chromosomes
-linked genes are usually inherited together

Question 23

Crossing over

Answer 23

during synapsis in the first meiotic division, the chromatids in a
homologous pair of chromosomes often twist around each other, break, exchange segments and rejoin.

Question 24

Karyotype

Answer 24

And in large photograph of the chromosomes in organism

Question 25

Mutations

Answer 25

Change in genetic material

Question 26

Non disjunction

Answer 26

homologous chromosomes fail to separate during meiosis, producing offspring with one chromosome more or less than is normal

Question 27

Disjunction

Answer 27

the separation of homologous chromosomes during meiosis

Question 28

Polyploidy

Answer 28

• The presence of one or more entire additional sets of chromosomes in an organism (3n,4n number, etc.)

Question 29

Mutantic agents

Answer 29

increase the random incidence of mutations 1. Radiation -- X-rays, ultraviolet, radioactive substances, and cosmic rays 2. Chemicals -- formaldehyde, benzene, asbestos fibers, THC, nicotine

Question 30

Artificial selection

Answer 30

-- individuals with desirable traits are mated to produce offspring with those

Question 31

Inbreeding

Answer 31

-- offspring produced by artificial selection are mated with one another to reinforce those desirable traits

Question 32

Hybridization

Answer 32

with different desirable traits to produce offspring with | a combination of both desirable traits

Question 33

Recombinant DNA (genetic engineering)

Answer 33

new varieties of plants and animals can be created by manipulating the genetic instructions of these organisms to produce new characteristics

Question 34

Translocation

Answer 34

transfer of one section of a chromosome to a nonhomologous chromosome

Question 35

Addition

Answer 35

A portion of one chromosome is transferred to another

Question 36

Inversion

Answer 36

a portion of a chromosome breaks off and then becomes reattached to the same chromosome in an inverted (upside down) fashion