cells and control - topic 2

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kelly tex

Cards (76)

what are chromosomes?
a structure found in the nucleus of a cell, containing genetic information in the form of DNA, which is organized into genes
what's a gene?
a section of DNA that codes for a specific protein or characteristic
how many chromosomes are there in each cell of the body?
46 chromosomes and 23 pairs
how many chromosomes do gametes have?
23 chromosomes
what does diploid mean?
has the full amount of chromosomes - 46
what does haploid mean?
has half the amount of chromosomes - 23 (gametes)
what do two haploid cells combine to form?
a diploid cell
what's the first stage in the cell cycle?
interphase
what's the second stage in the cell cycle?
mitosis
what's the third stage of the cell cycle?
cytokinesis
what happens during interphase?
cell grows, DNA replicates and energy stores increase
what are the 4 stages of mitosis?
prophase, metaphase, anaphase, telophase
what happens during prophase?
chromosomes condense and become more visible and the nuclear membrane breaks down
what happens during metaphase?
chromosomes line up in the centre of the cell
what happens during anaphase?
chromatids are pulled to opposite poles of the cell by spindle fibres
what happens during telophase?
new membranes are formed around the chromosomes at either end of the cell
why is cell division important?
growth, development and repair of damaged cells
what type of reproduction requires mitosis?
asexual reproduction
what is the product of mitosis?
2 genetically identical diploid daughter cells
what is differentiation?
process where unspecialised cells become specialised to preform specific functions
How does growth in plants occur?
By cell disposing ,differentiation and elongation
what is elongation?
The process where cells increase in length - plants grow longer unlike animal cells
how does cancer occur?
Small changes in cells that lead to uncontrolled cell division. The group of cells that results this uncontrolled division is called a tumour
What do percentile graphs tell us?
Tell us the rate at which an organism if interest is growing
what is a stem cell?
An undifferentiated cell that can undergo division to produce many more similar cells of which some will differentiate to have different functions.
What are the two types of human stem cells?
Adult stem cells and embryonic stem cells
How are embryonic stem cells formed?
When an egg and sperm cell fuse to form a zygote
Where are adult stem cells found?
Bone marrow
What types of cells can adult stem cells differentiate into?
limited number of related cell types but some inclide blood and immune system cells
What are stem cells in plants called?
Meristems
Where are meristems found?
In root and shoot tips
What’s therapeutic cloning?
involves an embryo being produced with the same genes as the patient
What’s an advantage of therapeutic cloning?
They would not be rejected as they would have the exact same genetic make-up as the individual
What are some benefits of research with stem cells?
Can be used to replace damaged or diseased body parts
Unwanted embryos from fertility clinics could be used as they would otherwise be discarded
Reader go into the process of differentiation
What are some problems with research with stem cells?
Don’t completely understand the process of differentiation
Removal of stem cells results in destruction it the embryo
Religious or ethical objections
If the growing stem cells are contaminated with a virus and infection can be transferred to the individual
What makes up the central nervous system?
Brain and the spinal chord
What are the four parts of the brain?
Cerebral cortex, cerebellum, medulla oblongata and hypothalamus
What is the cerebral cortex in charge of?
Consciousness - intelligence, languages, senses, memory, emotions
what is the cerebral cortex split into?
Cerebral hemispheres
What does the left side of the cerebral cortex control?
Right side