Genetics

Genetics

5.1

Cell Division

Chromosome

Nucleus contains chromosomes
Long and spiral
Consist nucleic acids and protein
Each chromosome contains a long DNA molecule

Deoxyribosenucleic acid (DNA)

Made up of nucleotide
Each nucleotide consists of three components, deoxyribose sugar, a nitrogenous base and a phosphate group
Double helix

Gene

Basic hereditary unit that determines an individual's characteristics
Function: to control the inherited characteristics in an organism

Gender	Autosome + sex chromosomes
Male	44 + xy
Female	44 + xx

Mitosis

Mitosis is a cell division process that forms 2 identical daughter cells.

A		Chromosome with two chromatids joined at the centromere
B	Prophase	Replication of chromosome occurs Chromosomes shorten and thicken Spindle fibres begin to form
C	Metaphase	Chromosome arrange at the equatorial plate of the cell
D	Anaphase	Pairs of chromatids seperate and move to the opposite poles of the cells
E	Telophase	Cytoplasm divides
F		Two daughter cells are formed Same number of chromosomes as parent cell

Meiosis

Meiosis is a process where the cell divides into 4 distinct cells

A		Parent cells with two pairs of chromosomes
B	Prophase I	Replication of chromosome occurs
C	Metaphase I	Crossing over occurs
D	Anaphase I	Homologous chromosomes seperate and move to opposite poles
E	Telophase I and cell division	Cytoplasm divides Two daughter cells are formed
F	Metaphase II	Pairs of chromatids separate and move to opposite poles Cytoplasms divides
G	Telophase II & cell division	Four daughter cells are formed Each daughter cells have half number of chromosome from parents

Similarities of mitosis and meiosis

A process of cell division
Purpose of both processes are to ensure sustainability of living organisms
Both transfer genetic material to daughter cells
Both process involve duplication of chromosome

Differences between mitosis and meiosis

	Mitosis	Meiosis
Definition	Cell division in which a cell divides into 2 cells	Cell division in which a cell divides into 4 cells
Location of process	Meristem cells in plants Somatic cells in animals	Anther and ovary in plants Testis and ovary in animals
Number of daughter cells	2	4
Number of chromosomes in daughter cell	Same number of chromosomes of the parents	Half the number of chromosomes of the parent cell
Genetic make up in daughter cells	Identical	Different
Products	Cells for growth and repair	Gamates
Importance	For growth For tissue repair Asexual reproduction Maintenance and continuity of life	Produce gametes Produce variation

Genetics

5.1

Cell Division

Chromosome

Nucleus contains chromosomes
Long and spiral
Consist nucleic acids and protein
Each chromosome contains a long DNA molecule

Deoxyribosenucleic acid (DNA)

Made up of nucleotide
Each nucleotide consists of three components, deoxyribose sugar, a nitrogenous base and a phosphate group
Double helix

Gene

Basic hereditary unit that determines an individual's characteristics
Function: to control the inherited characteristics in an organism

Gender	Autosome + sex chromosomes
Male	44 + xy
Female	44 + xx

Mitosis

Mitosis is a cell division process that forms 2 identical daughter cells.

A		Chromosome with two chromatids joined at the centromere
B	Prophase	Replication of chromosome occurs Chromosomes shorten and thicken Spindle fibres begin to form
C	Metaphase	Chromosome arrange at the equatorial plate of the cell
D	Anaphase	Pairs of chromatids seperate and move to the opposite poles of the cells
E	Telophase	Cytoplasm divides
F		Two daughter cells are formed Same number of chromosomes as parent cell

Meiosis

Meiosis is a process where the cell divides into 4 distinct cells

A		Parent cells with two pairs of chromosomes
B	Prophase I	Replication of chromosome occurs
C	Metaphase I	Crossing over occurs
D	Anaphase I	Homologous chromosomes seperate and move to opposite poles
E	Telophase I and cell division	Cytoplasm divides Two daughter cells are formed
F	Metaphase II	Pairs of chromatids separate and move to opposite poles Cytoplasms divides
G	Telophase II & cell division	Four daughter cells are formed Each daughter cells have half number of chromosome from parents

Similarities of mitosis and meiosis

A process of cell division
Purpose of both processes are to ensure sustainability of living organisms
Both transfer genetic material to daughter cells
Both process involve duplication of chromosome

Differences between mitosis and meiosis

	Mitosis	Meiosis
Definition	Cell division in which a cell divides into 2 cells	Cell division in which a cell divides into 4 cells
Location of process	Meristem cells in plants Somatic cells in animals	Anther and ovary in plants Testis and ovary in animals
Number of daughter cells	2	4
Number of chromosomes in daughter cell	Same number of chromosomes of the parents	Half the number of chromosomes of the parent cell
Genetic make up in daughter cells	Identical	Different
Products	Cells for growth and repair	Gamates
Importance	For growth For tissue repair Asexual reproduction Maintenance and continuity of life	Produce gametes Produce variation