Unit 1.1 Division & differentiation in human cells Flashcards
Name to describe an organism that consists of many cells
Multicellular
What is a somatic cell
Any cell in the body other than cells involved in reproduction
What do somatic cells divide by & what does this produce
Mitosis to produce more somatic cells
What are somatic cells produced by
Cellular differentiation
2 examples of somatic cells
Muscle cells, red blood cells
What are germline cells
Gametes & the stem cells that divide to form gametes
What do germline cells divide by
Mitosis & meiosis
What does mitosis in germline cells produce
More germline cells (diploid)
What are diploid cells
Cells containing 23 pairs of homologous chromosomes
What are homologous chromosomes
Chromosomes of the same size, with the same genes in the same position
What does meiosis in germline cells produce
Haploid gametes
What are haploid gametes
Gametes (sex cells) containing 23 single chromosomes
Differences between mitosis & meiosis in germline cells
Mitosis - 1 stage of division to produce 2 diploid germline cells
Meiosis- 2 stages of division to produce 4 haploid gametes
What happens in the first division of meiosis
The first division separates the homologous chromosomes
What happens in the second division of meiosis
The second division separates the chromatids
What is cellular differentiation
The process by which a cell expresses certain genes to produce proteins characteristic for that type of cell
What does cellular differentiation allow
The cell to carry out specialised functions
What are stem cells
Unspecialised somatic cells with the ability to become specialised cells
The 2 types of stem cells
Embryonic & tissue
The 2 things stem cells can do
Reproduce & differentiate