Genetics

Question 1

Alleles

Answer 1

A variation of a gene.

Question 2

Genotype

Answer 2

A combination of alles (e.g. AA, Aa, aa)

Question 3

Phenotype

Answer 3

A physical characteristic controlled by a genotype.

Question 4

AA

Answer 4

Homozygous dominant

Question 5

Aa

Answer 5

Heterosygous

Question 6

aa

Answer 6

Homozygous recessive

Question 7

Dominant

Answer 7

Is shown in phenotype if present

Question 8

Recessive

Answer 8

Is shown only if homozygous

Question 9

Incomplete dominance

Answer 9

Blended alleles to produce a third phenotype.

red alleles + white alleles = pink flowers (blended phenotype)

Question 10

Co-dominance

Answer 10

Both alleles are equally dominant and both traits are shown in phenotypes.

red allele + white allele = parts red + parts white in phenotype

Question 11

Meiosis

Answer 11

Cell division to produce sex cells (ova and sperm)

Question 12

autosome

Answer 12

A non-sex chromosome

Question 13

chromatid

Answer 13

One of two identical DNA strands forming a replicated chromosome and held together by a centromere

Question 14

Hemizygous dominant

Answer 14

Only one allele

Question 15

genome

Answer 15

The complete set of genetic information in an organism

Question 16

Karyotype

Answer 16

An individual’s complete set of chromosomes

Question 17

Sex-linked inheritance

Answer 17

Traits or disorders are influenced by genes on the X chromosome, as it contains many more genes than the smaller Y chromosome.

Males, who have only a single copy of the X chromosome, are more likely to be affected by a sex-linked disorder than females, who have two copies

Question 18

Test cross

Answer 18

A test cross involves mating an unknown genotypic individual with a known homozygous recessive