Inheritance

Question 1

DNA

Answer 1

Found in the nucleus of all cells in the body, Contains a nitrogenous base, phosphate and deoxyribose sugar, Backbone- made up of sugars and phosphates

Question 2

Bases

Answer 2

Adenine, Thymine, Guanine, Cytosine

Question 3

Nucleotide

Answer 3

sub unit of DNA, consists of deoxyribose sugar, phosphate head and nitrogenous base, connected by weak hydrogen bonds

Question 4

Chromosomes

Answer 4

DNA wrapped around proteins called histones, Found in both somatic (body) cells and gametes (sex cells), Somatic cells have pairs of chromosomes, Gametes have single chromosomes

Question 5

Gene

Answer 5

Section of DNA that controls a trait

Question 6

Homologous pair

Answer 6

Two chromosomes with the same gene but different expression

Question 7

Alleles

Answer 7

Alternative forms of a gene, Inherited from a person’s parents and controls and determines the characteristics of the individual, Many genes have two alleles, one that is dominant and one that is recessive

Question 8

Heterozygous

Answer 8

Different alleles

Question 9

Homozygous

Answer 9

Same alleles

Question 10

Genotype

Answer 10

Genetic make-up (code) of an individual, Inherited

Question 11

Phenotype

Answer 11

Observed expression of the alleles for the characteristic (physical expression), Determined by genotype and environment

Question 12

Monogenic inheritance

Answer 12

When an individual receives just one pair of alleles for a trait meaning there are only two phenotypes, Traits are discrete (trait is either there or not), Eg- blood grouping, freckles, widow’s peak, attached earlobe

Question 13

Polygenic inheritance

Answer 13

Many pairs of genes control the trait, Continuous variation and an additive effect (not dominant and recessive), Continuous and present in varying degrees (not discrete), Eg- Skin colour, height, weight, Assumptions- each gene has two alleles, one which is contributing and one which is non-contributing, there is no dominance, effect of each contributing allele is additive

Question 14

DNA replication

Answer 14

Process where new strands of DNA are made
Steps: Two strand of the original DNA molecule separate (unzip), Each separate strand of the original DNA molecule acts as a template, Complementary bases pair up to the bases on the template strand, Results in two identical DNA molecules