Edexcel Biology - Cells and Control (Mitosis & Cell cycle)

What structures do coils of DNA make up? They are found in the nucleus

Chromosomes

What is a gene?

short section of DNA

codes for a protein

controls characteristics

How many chromosomes in each cell (gametes) of the body?

46 chromosomes or 23 pairs

How many chromosomes are found in gametes?

23 chromosomes

What is a gamete?

sperm or egg cell

What happens during mitosis?

Mitosis is a step in the cell cycle…

The cell divides

What happens during stage 1, interphase, of the cell cycle?

cell grows

organelles grow and increase in number

protein synthesises

DNA replicated

energy stores increased

What happens during prophase of the cell cycle?

spindle fibres begin to form

chromosomes condense and become visible

What happens during mitosis of the cell cycle?

(more in depth)

chromosomes line up at equator of the cell

cell fibres pull each chromosome (of a pair) to either side of the cell

contains the two stages of metaphase and anaphase (explained in other cards)

What happens during metaphase of the cell cycle?

chromosomes line up at the metaphase plate along the equator of the cell

What happens during anaphase of the cell cycle?

spindle fibres pull the chromosomes apart from their pairs

What happens during telophase of the cell cycle ?

chromosomes arrive at the opposite poles

nuclear envelopes form around each set of chromosomes

spindle fibres break down

What happens during cytokinesis of the cell cycle?

two identical daughter cells form when the cytoplasm and cell membranes divide

What is differentiation?

Differentiation occurs when a stem cell becomes specialised

differentiate to become a specific cell to carry out specific function in the body

e.g. muscle cell

Where are stem cells found in adults?

bone marrow

Name all three types of stem cells (animals and plants)

embryonic stem cells

adult stem cells

meristems

Where are meristems found in plants

roots and shoots