Inheritance, variation and evolution (Paper 2) Flashcards
(27 cards)
1
Q
What does DNA stand for
A
- Deoxyribonucleic acid
2
Q
What is contained within DNA
A
- Coded information, all the instructions to put an organism together and make it work
3
Q
What does DNA determine
A
- What inherited characteristics you have
- What proteins the cell produces (haemoglobin, keratin)
4
Q
What type of molecule is DNA
A
- A polymer
5
Q
Define gene
A
- Small section of DNA found on a chromosome
6
Q
What do genes do
A
- Codes for a particular sequence of amino acids which are put together to make a specific protein
- Tell cells what order to put amino acids together
7
Q
How many amino acids do genes code for
A
- 20 but they make up thousands of different proteins
8
Q
Define genome
A
- The entire set of genetic material in an organism
9
Q
What does identifying the human genome do
A
- Allows scientists to identify genes in the genome that are linked to different diseases
- Helps understand and treat inherited diseases
- Understand the migration of humans
10
Q
What is the order of classification
A
- Domain
- Kingdom
- Phylum
- Class
- Order
- Family
- Genus
- Species
11
Q
Define nucelotides
A
- The repeating units contained within DNA polymers
12
Q
What molecules make up nucleotides
A
- A sugar molecule, a phosphate molecule and a base
13
Q
List the types of complimentary base pairing
A
- A and T
- C and G
14
Q
Function of mRNA
A
- Proteins are made in the cytoplasm of ribosomes
- To make proteins, ribosomes use the code in the DNA
- The cell needs to get the code from the nucleus to the ribosomes as the DNA in the nucleus cannot move
- mRNA is made by copying the code from the DNA
- The mRNA acts as a messenger between the nucleus and the DNA, carrying the code between the two
- The correct amino acids are then brought to the ribosomes in the correct order by the carrier molecules
15
Q
Functions of proteins in the body
A
- Enzymes
- Hormones
- Structural proteins
16
Q
Define mutation
A
- A random change in an organisms DNA
17
Q
Effects of mutation on DNA
A
- Mutations change the sequences of the DNA bases in a gene, causing genetic variation
- As the sequence of DNA bases codes for the sequence of amino acids that make up a protein, mutations in a gene sometimes change the protein that it codes for
18
Q
Define insertion mutations
A
- When a new base is inserted into the DNA base sequence when it shouldn’t be
19
Q
Define deletion mutations
A
- When a random base is deleted from the DNA base sequence
20
Q
Define substitution mutations
A
- When a random base is replaced by a different random base in the DNA base sequence
21
Q
Define sexual reproduction
A
- When the genetic information from two parents is combined via the gametes to produce an offspring that is genetically different from the parents
22
Q
How does asexual reproduction occur
A
- Via mitosis, an ordinary cell produces a genetically identical cell by dividing in two
23
Q
List the steps in miosis
A
- The DNA replicates itself and organises itself into pairs
- In the first division, the pairs organise themselves into the middle and are pulled apart so each new cell only has one copy of each chromosome
- In the second division, the chromosomes line up at the centre of the cell and the arms of the chromosomes are pulled apart
24
Q
Cause and effect of cystic fibrosis
A
- Caused by a genetic disorder in the cell membranes
- Causes the body to produce thick, sticky mucus in the air passages and pancreas
25
Function of parts of DNA that don't code for proteins
- Responsible for determining whether a gene is expressed and if a protein is coded for or not
26
How do strawberry plants reproduce asexually
- They produce runners which are stems that grow horizontally on the surface of the soil away from a plant
- At various points along the runner, a new strawberry plant forms that is genetically identical to the original plant
27
Define allele
- An alternative version of a gene
