Cell Division Flashcards
where is the genetic material stored in the cell
nucleus
the DNA is arranged in structures call ………………..
chromosomes
what does each chromosome carry
different genes
what are genes
a gene is a specific section of DNA that codes for the production of one specific protein
what do different genes determine
different genes determine the development of specific characteristics
in body (somatic) cells how are chromosomes found in
pairs
how many chromosomes are in a somatic cell
46 chromosomes , 23 pairs
what is it called when the full number of chromosomes are found inside the nucleus of a somatic cell
diploid cell
somatic cells in a multicellular organism must be able to divide + produce new cells so that : (4 reasons)
- damaged + old cells are replaced
- tissues + organs can be repaired
- tissues + organs can grow
- the organism itself can grow
what are the 2 main stages of the cell cycle
- Cell growth + DNA replication
- Mitosis
describe the stages in the cell growth phase
- cells get bigger
- DNA doubles –> forms 2 copies of each chromosome
- sub-cellular structures like ribosomes + mitochondria double
describe the stages of mitosis
- chromosomes line up in the middle / equator of the cell
- half of the chromosomes are pulled to each pole of the cell
- 2 nuclei form within the cell –> nucleus divides
- cytoplasm, organelles + cell membrane + nuclei are split to form 2 new daughter cells which are genetically identical
what type of reproduction is binary fission
asexual reproduction
how is bacteria difference from mitosis
- mitosis is the division of the nucleus BUT bacteria do not have nuclei
- spindle fibres also not formed in binary fission
describe the stages of binary fission
- cell replicates DNA
- increase in size
- divide into 2 genetically identical daughter cells