The Gene Flashcards
Define Meiosis
The division of cells in the reproductive system.
What happens during meiosis?
The cell divides twice, producing four cells with half of the usual genetic information, on a random basis.
What is DNA?
The genetic coding of the body.
How is DNA stored?
In 46 individual chromosomes for each cell. These contain genes (glorified proteins).
Define allele
A variant or characteristic of a gene. For example, hair colour.
What is the term for a variant of a gene?
An allele.
What is the name for the division of cells in the reproductive system?
Meiosis.
Which letters combine in genes?
A+T, and G+C.
Define mitosis
Mitosis is the type of cell division that happens in most of the body
Define chromosone
The carrier of genetic information. It is made up of DNA
How are chromosones found?
In pairs
How many pairs of chromosomes do we have?
23
What are chromosomes made up of?
Genes
What are genes?
The specific code (AT GC)
What are genes?
Strings of protein
What is the purpose of mitosis?
Growth, repairing, and replacement
Describe the process of mitosis
DNA splits to form two copies of each chromosone
Chromosomes line up along the edge of a cell
The cell splits
The cytoplasm and cell membranes divide to form two identical cells
What are the cells resulting from mitosis called?
Daughter cells
What is cancer?
Uncontrollable mitosis
What is the name for chemicals that could cause cancer?
Carcinogens
How do carcinogens cause cancer?
By damaging DNA and causing mutations
What are the two factors in developing cancer?
Lifestyle factors and environmental factors
Give two examples of lifestyle factors relating to cancer
- Chemicals in cigarette smoke
- Alcohol intake
Give two examples of environmental factors in cancer
- Exposure to radiation
- Exposure to chemical carcinogens from smoke
What is the name for a sex cell?
A gamete
Define a zygote
A fertilised egg cell
What are the gametes in plant cells?
Pollen and eggs
Describe the process of meiosis
- Copies of the genetic information are made
- The cell divides twice so each cell only has one set of chromosomes
Take a look at this :)
What are stem cells?
Cells which haven’t undergone differentiation
Where can adult stem cells be found?
In the brain, blood and heart
Are adult stem cells more limited?
Yes
When are stem cells used?
For type one diabetes, for multiple sclerosis, and for spinal chord injury
Sorry admire this again
Where does cell division happen in plants?
In meristems
Where are the main meristems?
Near the top of the shoot
What shape does DNA take?
A double helix
Where are chromosonmes?
In a cell’s nucleus
What are chromosones?
Long threads of DNA
What is a genotype?
A collection of alleles
What is a phenotype?
The physical representation of a genotype
How are dominant alleles represented?
With a capital letter
When is a recessive allele represented?
If the person only has recessive genes
What are homozygous alleles?
AA or aa
What are heterozygous alleles?
Aa
What is the backbone of DNA made up of?
Sugar and phosphate
What are bases in DNA?
Paired chemicals (TAGC)
What do TAGC stand for?
T - thymine
A - adenine
G - guanine
C - cytosine
read thiss
What is the sequence of an amino acid determined by?
The triplet code - a code of three bases
What are 22 of the 23 pairs of chromosomes known as?
Autosomes - they control characteristics
Which chromosomes do men have?
XY - they are incomplete hehe
What’s the term for when we analyse DNA?
Genetic profiling
How do we do genetic profiling?
By cutting a sample of DNA into fragments and separating said fragments by size
When do we use genetic profiling?
To solve crimes or determine parenthood
How do you produce a DNA fingerprint?
Give two advantages and two disadvantages of DNA profiling
Adv - Very reliable, used to determine genetic disorders early
Dis - Invasion of privacy? Theft of DNA has unknown potentials
What does genetic engineering involve?
Taking genes from one organism and putting them in another
What do we use genetic engineering for?
To create crops that can produce their own insecticide or that have advantages for the climate
What are the negatives of GM crops?
They can be monopolised or spread without control
