Cell Division Flashcards
What is a chromosome?
Structure of DNA and protein
What is the role of a chromosome?
Contains genes that code for protein
What is cell continuity?
All cells develop from pre-existing cells
What are the 2 types of cell division?
Mitosis and Meiosis
What are somatic cells?
Body cells except gamete’s
Diploid (2n)=produced by mitosis
What are gametes?
Cells capable of fusion (Haploid)
How many copies of chromosomes are there in a diploid cell?
Two copies of each chromosomes
How many copies of chromosomes are there in a haploid cell?
One copy of each chromosome
Definition of mitosis?
Form a cell division, one nucleus divides to form two identical nuclei with the same number of chromosomes
Function of mitosis in unicellular
Asexual reproduction
Function of mitosis in multicellular organisms
Growth and repair of tissues
Cells that do not undergo mitosis
1.Red blood cells
2.Gametes
Cells that are not produced by mitosis
Gametes (sperm and egg)
What is cancer?
Group of cells lose ability to control the rate of mitosis
Types of cancer?
Benign and malignant
What do carcinogens do?
Agents that cause cancer
Examples of carcinogens
Ultra violent rays (UV)
Define Meiosis?
Form of cell division, one nucleus divides to form 4 un-identical nuclei with half the number of chromosomes as the parent nucleus
Where does meiosis occur?
In the testes and ovaries
Function of meiosis
1.Allows asexual reproduction/fertilisation without increasing the chromosome number
2.Genetic variation
Define interphase?
Stage on a cell cycle cell division is not taking place (90% of cycle)
Name the cellular activities?
Respiration, Photosynthesis, Protein synthesis
How are Biomolecules (food) made?
Protein and carbohydrates
How does the organelle replicated?
Mitochondria and chloroplasts (plant)
Processes involving genetic variation
Condensation and duplication
Name the 4 stages of mitosis
1.Prophase
2.Metaphase
3.Anaphase
4.Telophase
What happens in the Prophase?
1.Nuclear membrane breaks down
2.condensed visible chromosomes
3,spindle fibres forming
What happens in the metaphase?
1.Spindle attached to chromosome’s at centromere
2.chromosomes lined up at equator
What happens in the anaphase?
1.spindle fibres contract
2. Identical chromosomes pulled apart
What happens in the telophase
1.new nuclear membrane forms
2.spindles broken down
3.two new identical nuclei forms
Define cytokinesis?
Splitting of cell itself as mitosis is ending
Cytokinesis in animal cells
Cleavage furrow splits cell in two
Cytokinesis in plant cells
Cell wall prevents cleavage furrow
Cell plate forms instead - becomes two cell walls
