Genetics

Question 1

Allele

Answer 1

variation of the same sequence of nucleotides at the same place on a long DNA molecule, as described in leading textbooks on genetics and evolution.

Question 2

Homozygous

Answer 2

both alleles for the gene are the same

Question 3

Heterozygous

Answer 3

having two different alleles of a particular gene or genes

Question 4

DNA (deoxyribonucleic acid)

Answer 4

Thread-like chain of nucleotides carrying the genetic instructions in a double-helix of anti-parrallel strands.

Question 5

RNA (ribonucleic acid)

Answer 5

Singular strand, thread-like chain of nucleotides carrying genetic instructions for forming a protein

Question 6

Genes

Answer 6

Composed of sections of DNA and control the way an organism develops, grows and functions. They are tightly coiled into x-shaped structures (chromosomes)

Question 7

Dominant allele

Answer 7

dominant allele produces a dominant phenotype in individuals who have one copy of the allele, which can come from just one parent.

Question 8

Recessive allele

Answer 8

A recessive allele does not produce a trait at all when only one copy is present.

Question 9

Polygenic

Answer 9

multiple gene inheritance

Question 10

Monohybrid x

Answer 10

A monohybrid cross is one in which both parents are heterozygous (or a hybrid) for a single (mono) trait.

Question 11

Dihybrid x

Answer 11

A dihybrid cross describes a mating experiment between two organisms that are identically hybrid for two traits.

Question 12

Phenotype

Answer 12

the set of observable characteristics of an individual resulting from the interaction of its genotype with the environment.

Question 13

Genotype

Answer 13

the genetic constitution of an individual organism.

Question 14

Wild-type allele

Answer 14

A term used to describe a gene when it is found in its natural, non-mutated (unchanged) form.

Question 15

pure bred

Answer 15

not mixed or adulterated with any other substance or material.

Question 16

Sex linked

Answer 16

Sex-linked, as related to genetics, refers to characteristics (or traits) that are influenced by genes carried on the sex chromosomes.

Question 17

Law of segregation

Answer 17

Genes for a characteristic occur in pairs in an individual. One inherited from each parent

Question 18

Law of independent assortment

Answer 18

When two or more characteristics are inherited, individual heredity factors assort independently giving different traits an equal opportunity to occur together

Question 19

Codominance

Answer 19

a type of inheritance in which two versions (alleles) of the same gene are expressed separately to yield different traits in an individual.

Question 20

Incomplete dominance (intermediate/partial)

Answer 20

a form of Gene interaction in which both alleles of a gene at a locus are partially expressed, often resulting in an intermediate or different phenotype.