Topic 2.3 The Cell Cycle Flashcards
What is Asexual reproduction?
Asexual reproduction is the production of genetically identical offspring from a single parent or organism
What is sexual reproduction?
Sexual reproduction is the production of offspring that are genetically different from the parent organism or organisms by the fusion of two sex cells (gametes)
What is meiosis?
Meiosis is a form of cell division in which the chromosome number of the original cell is halved, leading to the formation of gametes
What are Histones?
Histones are positively charged proteins involved in the coiling of DNA to form dense chromosomes in cell division
What are Nucleosomes?
Nucleosomes are dense clusters of DNA wound around around Histones
What is a Karyotype?
A Karyotype is a way of displaying an image of the chromosomes of a cell to show pairs of autosomes and sex chromosomes
What is the cell cycle?
The cell cycle is a regulated process of three stages (interphase, mitosis and cytokinesis) in which cells divide into two genetically identical daughter cells
What’s is interphase?
Interphase is the period between active cell divisions when the cells increase in size and mass, replicate DNA and carry out normal metabolic activities
What happens in G1?
The cells assimilates material, grows and develops.
What happens at S?
Chromosomes are replicated and become double stranded chromatids
What is mitosis?
Mitosis is the process by which a cell divides to produce two genetically identical daughter cells
What happens at G2?
Organelles and other materials needed for cell decision are synthesised. “Double checking” of the cell.
What is a chromatid?
A chromatid is one strand of the replicated chromosome pair that is joined to the other chromatid at the centromere
What are cyclins?
Cyclins are small proteins that build up during interphase and are involved in the control of the cell cycle by the attachment to cyclin-dependent kinases
What are cyclin-dependent kinases (CDKs) ?
Cyclin-dependent kinases are enzymes involved in the control of the cell cycle by phosphorylating other proteins, activated by attachment to cyclins
