T16 GENETICS

Question 1

Karyotype

Answer 1

a diagram showing the number and structure of chromosomes in an organism.

Question 2

sex chromosome

Answer 2

an x or y chromosome

Question 3

autosome

Answer 3

a chromosome that isn’t a sex chromosome

Question 4

Diploid

Answer 4

having chromosomes arranged in homologous pairs, with one inherited from the father and one inherited from the mother.

Question 5

gene

Answer 5

a length of DNA/ sequence of bases coding for a specific polypeptide.

Question 6

genotype

Answer 6

alleles present in an organism, unaffected by the environment.

Question 7

homozygous

Answer 7

pair of identical alleles for a gene

Question 8

heterozygous

Answer 8

two different alleles for a gene.

Question 9

dominant

Answer 9

an allele that is always expressed in the phenotype when present.

Question 10

recessive

Answer 10

an allele that is only expressed when no dominant allele is present.

Question 11

pure breeding

Answer 11

homozygous individuals bred as a result of breeding homozygous genotypes repeatedly

Question 12

huntingtons

Answer 12

autosomal dominant condition affecting neurones

Question 13

cystic fibrosis

Answer 13

recessive autosomal condition

mutation of CFTR transport gene for chloride ions outside of cell affecting mucus fluidity

Question 14

codominance

Answer 14

when 2 alleles are both expressed to form a third phenotype. both alleles have an effect on the the phenotype of a heterozygous organism.