1/8
Looks like no tags are added yet.
Name | Mastery | Learn | Test | Matching | Spaced |
---|
No study sessions yet.
Meiosis occurs during the life cycle of organisms. What is the importance of meiosis (2)
Haploid has half the chromosom (1)
Full number restored at fertilization (1)
Describe two events during interphase which prepare a cell for mitosis (2)
DNA replicate (1)
Increase in cytoplasm (1)
A sample of epithelial tissue from the small intestineof an animal was analysed. Some of the cells has 8.4 units of DNA, others had only 4.2 units
Use your knowledge of the cell cycle to explain why some cells has 8.4 units of DNA and others had only 4.2 units (2)
8.4/cells with twice DNA content - replicated DNA
4.2 = DNA not replicated (1)
In prophase of mitosis, the chromosomes become visible. Describe what happens in
Metaphase
Anaphase (4)
Metaphase- chromatids attached to spindle (1)
Its spindle fibres organize chromosomes to line up across the equator (1)
Anaphase- chromatids are pulled to opposite poles (1)
Chromatids separate (1)
Cells lining the human intestine complete the cell cycle in a short time. Explain the advantage of these cells completing cell cycle in a short time (1)
Replace cells quickly (1)
The time required for a cell to complete the cell cycle was 4 hours 18 minutes.
Calculate the time required in minutes for this cell to multiply to produce eight cells (2)
258×3 = 774(2)
The graph below shows how the quantity of DNA, measured in arbitrary units, varies with time during different phases of the cell cycle in an animal cell
Interphase is made of two growth phases, G1 and G2 separated by an intermediate phase,S
Explain what is happening within the cell during phase S (2)
DNA is replicated (1)
It doubles from 2 to 4 units (1)
State one process other than cell growth which occurs during phase G2 (1)
Proteins made (1)
Use the curve for the concentration of DNA to find the length of a cell cycle in these yeast cells. explain how you arrived at your answer (3)
Length of cell cycle - 3 hours (1)
Explanation - time between beginnings DNA replication (1)
DNA replication takes place once per cell cycle (1)