Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
21 Cards in this Set
- Front
- Back
|
What is Apotosis? |
Programmed cell death |
|
|
What cells produce the signalling molecules, and what cells receive them? |
Signalling cells produce signals, and target cells receive them. |
|
|
What is recognition in cell signalling? |
Recognition occurs when the signal binds to a specific site on the receptor because it is a complimentary shape. |
|
|
What is transduction in cell signalling? |
Transduction occurs when the signal molecule attaches to the receptor and is converted into another chemical form so that it can produce a cellular response. |
|
|
What is direct cell communication? |
When cells are in direct contact. Protein channels connect the two adjoining cells. |
|
|
How do animal cells send direct signals? |
They use gap junctions. |
|
|
How do plant cells send direct signals? |
They use plasmodesmata (a narrow thread of cytoplasm that passes through the cell walls of adjacent cells to allow for communication) |
|
|
What is indirect cell communication? Give examples of the systems that use it. |
When a signal travels from a signalling cell to a target cell that aren't in direct contact. For example, the endocrine and nervous systems. |
|
|
What are the types of signalling molecules? |
Plant hormones, hormones, neurotransmitters, pheromones. |
|
|
What are the types of chemical messengers? |
Paracrines, autocrines, neurotransmitters, hormones and neurohormones. |
|
|
What are neurohormones? |
Hormones released in to the bloodstream by neurosecretory neurons. They're distributed through blood to distant target cells. |
|
|
What is paracrine signalling? |
A form of cell to cell communication in which a cell produces a signal to induce changes in nearby cells. The signal will only have an effect on neighbouring cells in the immediate environment of secretion. |
|
|
What is autocrine signalling? |
A form of cell signalling in which a cell secretes a hormone or chemical messenger that binds to autocrine receptors on the same cell. |
|
|
What are the types of plant growth factors? |
Auxins, gibberellins, ethene/ethylene, cytokinins and Abscissic Acid (ABA). |
|
|
What do gardeners use plant hormones for? |
Growing cuttings, killing weeds and ripening fruit. |
|
|
What is photoperiodism? |
The physiological response of plants to the length of day and night. Long day plants need more that 12 hours of daylight/day, short day plants need less than 12 hours daylight/day and day-neutral plants are unaffected by the length of day/night. |
|
|
What do auxins do? |
-Promote cell growth -Inhibit the growth of side shoots -Inhibit leaf abscission (leaf fall) -Involved in photoperiodism |
|
|
What do gibberellins do? |
Promote seed germination and stem growth |
|
|
What does ethyne/ethylene do? |
Promotes fruit ripening and leaf abscission (leaf fall). |
|
|
What does cytokinins do? |
Promotes cell division. |
|
|
What does ABA do? |
ABA (abscissic acid) inhibits seed germination and growth, and causes stomatal closure for water conservation. |
