B6 - Inheritance, Variation And Evolution Flashcards Preview

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Flashcards in B6 - Inheritance, Variation And Evolution Deck (11):
1

DNA

- It's the chemical that all of the genetic material in the cell is made up of
- It contains coded information
- It determines your inherited characteristics
- Found in the nucleus of animal and plant cells, in really long structures called chromosomes
- Chromosomes normally come in pairs
- DNA is a polymer. It's made up of two strands coiled together in the shape of a double helix

2

Genes

- Small section of DNA found on a chromosome
- Each gene codes for a particular sequence of amino acids which are put together to make a specific protein
- Tells cells in what order yo put the amino acids together

3

Genome

the entire set of genetic material in an organism

4

Sexual reproduction

involves the fusion of male and female gametes
Because there are two partners, the offspring contains a mixture of their parent' genes

5

Asexual reproduction

only one parents. There is no fusion of gametes, no mixing of chromosomes and no genetic variation between parent and offspring. The offspring is a clone of the parent

6

Meiosis

- The cell duplicates its genetic information, forming two armed chromosomes.One arm of each chromosome is an exact copy of the other arm. After replication, the chromosomes arrange themselves into pairs
- In the first division the chromosome pairs line up on the centre of the cell
- The pairs are pulled apart so each new cell only has one copy of each chromosome
- In the second division, the chromosomes line up again in the centre. The arms of the chromosomes are pulled apart.
- you get 4 gametes, each with a singled set of chromosomes in it. Each of the gametes is genetically different

7

For embryo screening

- stop people suffering
- Laws to stop it going too far

8

Against embryo screening

- It implies that people with genetic problems are 'undesirable'
- Expensive

9

Genetic engineering

- A useful gene is cut from one organism's genome using enzymes and is inserted into a vector
- The vector is usually a virus or a bacterial plasmid
- The useful gene is inserted into the cells.

10

Classification

Kingdom
Phylum
Class
Order
Family
Genus
Species

11

three-domain system

- 1990 by Carl Woese
Archaea - Primitive bacteria. Found in places such as hot springs and salt lakes
Bacteria - Contains true bacteria like E.coli and Staphylococcus.
Eukaryota - Broad range of organisms including fungi, plants, animals and protists.