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Description
Flashcards by fahimarehman04, updated more than 1 year ago
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Created by fahimarehman04
over 10 years ago
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| Question | Answer |
| Name same advantages of being multicellular! | It allows an organism to become larger and therefore more complexed. It allows different cells to take on different jobs (cell differentiation). |
| What things must the system have for an organism to become multicellular? | -allow communication between all cells on the body -supply all cells with enough nutrients -control exchanges with the environment |
| What is mitosis? | The process that produces new cells for growth. |
| The cells that are made by mitosis are genetically identical. Before cells divide, DNA replication must take place. Why? | So that each cell produced still has two copies of each chromosome. |
| What are diploid cells? | Mammals have these body cells, it is having two copies of each chromosomes. |
| Before mitosis happens, DNA is replicated. This involves: | -The two strands of the DNA molecule unzipping to form single strands -new double strands forming by DNA bases lining up in complementary pairings. |
| Once mitosis occurs, what happens? | The chromosomes line up along the centre of the cell and divide. The copies then move to the opposite poles of the cell. |
| What is meiosis? | The type of cell division that produces gametes. |
| How are genetics haploid cells? | They contain only one chromosome from each pair. This means that the zygote gets one copy of a gene from one parent and another from the other. This produces genetic variation. |
| What is the structure of a sperm cell and how is it adapted to its function? | It has many mitochondria to provide energy for swimming to the egg. It has an acrosome that releases enzymes to digest the egg membrane. |
| What are the two divisions in meiosis? | First the single strands are copied to make x-shaped chromosomes and chromosomes with the same genes pair up. Then in the first division one chromosome from each pair moves to the opposite poles of the cell. In the second division, the copies of each chromosome come apart and move to the opposite poles of the cell. |
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