HUMAN REPRODUCTION
#1. DEFINITIONS
(i) Discontinuous variation : variation with a clear set of options. Eg: tongue rolling.
(ii) Continuous variation : variation that varies slowly. Eg: skin colour, height.
(iii) Environmental variation : variation caused by the environment.
(iv) Inherited variation : variation caused by the organism’s parents.
(v) DNA : it carries genetic information.
(vi) Gene : section of DNA that controls the development of a characteristic.
(vii) Chromosomes : long DNA structure with some proteins.
(viii) Egg cell : female gamete | Sperm cell : male gamete.
(ix) Fertilization : When an egg cell nucleus and a sperm cell nucleus join and form a
fertilized egg cell.
(x) Embryo : small ball of cells that develops from a fertilized egg cell.
(xi) Inheritance : passing of features from parents to children.
(xii) Sex chromosome : Chromosomes that control whether someone is male or
female.
(xiii) Adaptation : character of an organism that helps it survive in an ecosystem.
(xiv) Evolution : Gradual change in something over time.
(xv) Natural selection : Process by which organism have better adaptations for new
#1. DEFINITIONS
(i) Discontinuous variation : variation with a clear set of options. Eg: tongue rolling.
(ii) Continuous variation : variation that varies slowly. Eg: skin colour, height.
(iii) Environmental variation : variation caused by the environment.
(iv) Inherited variation : variation caused by the organism’s parents.
(v) DNA : it carries genetic information.
(vi) Gene : section of DNA that controls the development of a characteristic.
(vii) Chromosomes : long DNA structure with some proteins.
(viii) Egg cell : female gamete | Sperm cell : male gamete.
(ix) Fertilization : When an egg cell nucleus and a sperm cell nucleus join and form a
fertilized egg cell.
(x) Embryo : small ball of cells that develops from a fertilized egg cell.
(xi) Inheritance : passing of features from parents to children.
(xii) Sex chromosome : Chromosomes that control whether someone is male or
female.
(xiii) Adaptation : character of an organism that helps it survive in an ecosystem.
(xiv) Evolution : Gradual change in something over time.
(xv) Natural selection : Process by which organism have better adaptations for new
