cell biology Flashcards
How does water move from the roots to the leaves?
By the transpiration stream in the xylem.
Why is having very few stomata on the upper surface of the leaf beneficial to the plant?
Less water will be lost so it doesn’t wilt.
What type of cell division makes gametes?
Meiosis.
What are the 2 types of cell division?
Mitosis and meiosis.
Water moves out of the potato by the process of…? (practical)
Osmosis.
Name 2 advantages of using an electron microscope over a light microscope.
~Higher magnification
~Higher resolution
What is the structure inside the cell nucleus that contains DNA?
Chromosomes.
What type of substance does a gene code for?
Protein.
What type of cell division produces sperm cells?
Meiosis.
Why do organisms with smaller volume to surface area ratios require respiratory systems?
The diffusion distance is too large to meet the demands of the organism/cell.
Which 2 alveoli and villi adaptations reduce the diffusion time?
~Thin/one cell thick walls
~In close proximity to the blood supply
What are chromosomes?
Coiled up lengths of DNA molecules that carry a large number of genes.
What do genes control?
The development of different characteristics.
How does a cell grow before it divides?
By increasing the amount of sub cellular structures it has eg. mitochondria and ribosomes.
What is mitosis used for?
To grow or replace cells that have been damaged.
What two cell components divide last in mitosis?
The cytoplasm and the cell membrane.
What pulls the chromosomes in the centre of a cell apart (to opposite ends of the cell) ?
Cell fibres.
What is the product of mitosis?
Two identical daughter cells.
Which type of cells replicate by binary fission?
Prokaryotic cells.
What is replicated in binary fission?
Circular DNA and plasmids.
