genetics and heredity

Question 1

law of segregation

Answer 1

States that, for each characteristic, an organism possesses 1 gene consisting of 2 alleles which separate during meiosis so that each gamete only contains 1 allele.

Question 2

Law of Dominance

Answer 2

states that when two individuals with pure breeding (homozygous) contrasting characteristics are crossed, the individuals of the F1 generation all display the dominant characteristics.

Question 3

Law of Independent Assortment

Answer 3

states that the various “factors” controlling the different characteristics (seeds shape, seed colour, plant height, and flower colour) are separate entities, not influencing each other in any way, and sorting themselves out independently during gamete formation.

Question 4

Gene

Answer 4

particular length of DNA at a particular location (locus) on a chromosome that influences a particular characteristic.

Question 5

Allele

Answer 5

alternative form of a gene found at the same location (locus).

Question 6

Dominant allele

Answer 6

allele that is always expressed in the phenotype and represented by a capital letter.

Question 6

Recessive allele

Answer 6

allele that is only expressed in the phenotype if the dominant allele is not present. Represented by the lower case letter, same letter as the dominant allele.

Question 7

Locus

Answer 7

the location of a gene on the chromosome.

Question 8

Phenotype

Answer 8

the external (physical) appearance of an organism.

Question 9

Genotype

Answer 9

the genetic composition of an organism.

Question 10

Homozygous -

Answer 10

organism has 2 copies of the same allele for that characteristic

Question 11

Homozygous

Answer 11

organism has 2 different variations of the allele for that characteristic.

Question 12

Autosome -

Answer 12

referring to a chromosome that is not a sex chromosome.

Question 13

Gonosome

Answer 13

referring to a sex chromosome.

Question 14

Genome

Answer 14

the entire genetic blueprint of an organism.

Question 15

Karyotype

Answer 15

an individual’s collection of chromosomes

Question 16

sex-linked allele

Answer 16

an allele located on the sex chromosome.

Question 17

sex-linked disorder

Answer 17

a disease or abnormality determined by the genes located on the sex chromosomes.

Question 18

carrier

Answer 18

a heterozygous organism that carries an allele for a particular disorder without it being expressed.

Question 19

mutation

Answer 19

a sudden unexpected change in the genetic structure of a cell.

Question 19

mutagen

Answer 19

factor that cause mutations