B5 Flashcards
What is a meristem area?
Meristems are areas in plants of unspecialised cells.
Where are the three main meristem areas usually located?
The tip of the shoot, the tip of the root and along the plant stem.
What accelerates plant growth?
Auxins.
What area of the plant can you usually find the most auxins?
In the shaded areas.
Groups of specialsed cells are called ____.
Groups of ____ form ____.
Groups of ____ are called ____ _____.
Tissue, Tissues, Organs, Organs, Organ Systems.
What is a plant’s response to light and what is this called?
The plant will grow towards light. It is called phototropism and is essential for survival.
When a plant is exposed to light from the west what happens to the auxins? What deos this do?
The auxins would move to the east side which would accelerate growth there, this would then cause the plant to grow towards the light.
A fertilised egg (____) divides by ____ to form the embryo.
Zygote, Mitosis.
At the eight-cell stage, all the cells are embryotic stem cells, what does this mean?
The cells are unspecialised and can form into any type of specialised cell.
There are however some adult stem cells, where are these commonly found?
Bone marrow and red blood cells.
In plants, only cells in meristems can divide by ____. These cells can then become any other type of cell.
Mitosis.
What are the two main transporting tissues in plants?
Xylem and Phloem.
How many daughter cells are produced via mitosis?
Two.
Each daughter cell is ______ _____ to the parent and to each other.
Genetically Identical.
Meiosis is the type of cell division that produces _____ (__ ___).
Gametes (sex cells).
How many chromosones are in sex cells?
23 (There are no pairs), half as many as other cells.
What are the two parts of the cell cycle?
Cell growth and cell division.
What is cell growth?
When the numbers of organelles (structures in cells having a function) are increased and the DNA molecule of each chormosone is copied.
What is cell division?
When the two strands of DNA in each of the chromosone seperate, two nuclei form and the cytoplasm divides.
What shape is DNA and what does it look like?
Double Helix, like a twisted ladder.
The rungs of the ladder are called ___. There are _ bases in DNA. The bases always pair the same, _ with _ and _ with _.
Bases, 4, A with T; C with G.
The order of the bases in a gene is the instruction for the production of ____ ___ which are assembled into _____ in the _____ in the cytoplasm.
Amino Acids, Protein, Ribosomes.
The genetic code is part of the ___ in the nucleus. A copy is made (____) using the DNA as a template. The ____ leaves the nucleus to the cytoplasm where is attaches to a ______.
DNA, (mRNA), mRNA, Ribosomes.
All the cells in an organism have the ___ genes.
Only those genes required for a type of cell to function are _____ __. Other genes are _____ __, so the cell only synthesises the _____ it needs.
Same, Switched on, Switched off, Proteins.
