Topic 2 - Cells and Control Flashcards
in human cells, what is a chromosome?
a structure found in nuclei, containing a dna molecule
what type of cell division forms two identical daughter cells?
mitosis
what are the stages of mitosis
interphase prophase metaphase anaphase telophase cytokinesis
in which stage of the cell cycle are the chromosomes duplicated?
interphase
in which stage of the cell cycle, at the end of mitosis, does the one cell divide into two?
cytokinesis
what term describes a cell that has two sets of chromosomes?
diploid
where are plant meristems found?
tips of plant shoots & roots
what happens in a plant meristem?
cells divide rapidly by mitosis as the plant grows stem cells
what happens during cell differentiation?
cells develop special features that help them carry out a particular function
why is cell differentiation important to plants and animals?
specialised cells are more effective at carrying out different functions in the body
a root hair cell specialised to carry out its function?
increased surface area for absorption
explain how one specialisation of a xylem vessel helps it carry out its function
- thickened wall to prevent collapse of tube
- small holes in thick cell water can pass into and out of the vessel from surrounding cells
name one feature that could be measured to show growth in a plant
height, leaf area, number of leaves
name the type of cell division that cells use to make identical copies of themselves
mitosis
what type of cell has the ability to differentiate into specialised cells?
stem cells
what organ system would you find nerve cells?
the nervous system
are nerve cells diploid or haploid cells?
diploid
what part of a nerve cell contains chromosomes?
nucleus
what part of a nerve cell makes proteins?
ribosomes
nerve cells require a lot of energy. what cell structure would you expect them to have a lot of?
mitochondria
what is a nerve cell specialised to do?
carry out electrical signals/impulses
state the name of one organ in the nervous system
brain, spinal cord or nerves
what type of cells detect stimuli?
receptor cells
in which sense organ would you find receptor cells that detect light waves?
eye
what are the electrical signals used in the nervous system called?
impulse
list, in order, the organs that an impulse goes through from the hand to the brain
nerves –> spinal cord
what are the two long ‘arms’ of a sensory neurone called?
dendron & axon
list in order, the parts of a sensory neurone that an impulse goes through
dendrite, dendron, axon, axon terminal
why are sensory neurons so long?
to carry impulses quickly over long distances
what is the name of the fatty sheath that surrounds dendrons and axons?
myelin sheath
what does the myelin sheath do?
speeds up transmission of impulses, insulates neurons from each other
where in the eye are receptor cells for light found?
retina
What are stem cells
Special human cells that are able to develop into different type of cellsm
What type of cell are stem cells
Undifferentiated cells
How do cells form (white,red blood cells)
Bone marrow —> stem cell
How is cancer formed
Uncontrollable cell division caused by mutations in the DNA
Cell division that produces sperm cells
Meiosis
4 haploid cells
Generically different
Why do some offspring not inherit the disease
Do not inherit the disease causing allele.
