story of us

Question 1

what base does adenine go with?

Answer 1

thymine

Question 2

what base does cytosine go with?

Answer 2

guanine

Question 3

where is DNA located and how is it stored?

Answer 3

• nucleus
  -chromosomes

Question 4

what is a gene?

Answer 4

a section of DNA that codes for a protein

Question 5

what is continuous variation?

Answer 5

polygenic inheritance and is often significantly effected by environmental factors

Question 6

what are mutations?

Answer 6

change in the base sequence on DNA

Question 7

what are the three types of mutations?

Answer 7

• substitution
• deletion
• addition

Question 8

what increases the incidences of mutations?

Answer 8

-radioactivity
-carcinogens
-drugs
-uv/x-rays

Question 9

what is a genotype?

Answer 9

combination of two alleles possessed by an individual

Question 10

what is a dominant allele?

Answer 10

the allele is always expressed

Question 11

what is a recessive allele?

Answer 11

two alleles must be presented for the characteristic to be expressed

Question 12

what is homozygous?

Answer 12

an individual possesses two identical alleles for a specific gene

Question 13

what is heterozygous?

Answer 13

an individual possesses two different alleles for a particular gene

Question 14

what is a phenotype?

Answer 14

a feature/characteristic of an individual, coded for by their two alleles

Question 15

what is a diploid cell?

Answer 15

the cell contains a two sets of chromosomes

Question 16

what is a haploid cell?

Answer 16

the cell only contains a single set of chromosomes

Question 17

what is meiosis?

Answer 17

cell division producing haploid gametes, giving rise to genetic variation

Question 18

what is mitosis?

Answer 18

cell division producing genetically identical haploid cells for growth and repair

Question 19

what is an allele?

Answer 19

different forms of a gene, coding for different versions of the characteristic

Question 20

what is monogenic inheritance?

Answer 20

a characteristic controlled by one gene

Question 21

what is codominance?

Answer 21

when two alleles are equally expressed

Question 22

What is a mutation?

Answer 22

Random change in the base sequence of DNA

Question 23

What causes mutations?

Answer 23

UV
Radiation
X-rays
Carcinogens

Question 24

How does natural selection work with white mice?

Answer 24

They are not camouflaged
Do not surve as long as they are eaten
Do not reproduce and pass on the white allele
So eventually they disappear

Question 25

What does MVARPS stand for?

Answer 25

M - mutation V - variation in population A - advantage R - reproduce P - pass on allele S - several generations

Question 26

What kingdom are bacteria?

Answer 26

Prokaryotes (no membrane bound organelles)

Question 27

How quickly can bacteria reproduce and how?

Answer 27

Every 20 mins Binary fission

Question 28

What do antibiotics do?

Answer 28

Kill bacteria

Question 29

What type of white blood cell makes antibodies?

Answer 29

Lymphocyte

Question 30

What type of white blood cell engulfs a pathogen?

Answer 30

Phagocyte

Question 31

What are antigens?

Answer 31

Proteins that are a specific shape which are found not the outside of a cell They are used for cell recognition

Question 32

What type of cells are made when a pathogen enters the body for the second time?

Answer 32

Memory cells

Question 33

What does HIV cause?

Answer 33

AIDS

Question 34

What is a genome?

Answer 34

All the organisms in DNA

Question 35

What is the structure of DNA?

Answer 35

Double helix Deoxyribose sugar Long Contains ATGC

Question 36

What is the structure of RNA?

Answer 36

Single helix Ribose sugar Contains AUGC Short

Question 37

What are proteins made of?

Answer 37

Amino acids

Question 38

What is the process of transcription?

Answer 38

DNA is turned into mRNA by : - the RNA polymerase separating the gene - the RNA polymerase then reads the bases and forms a complementary base pairing - the mRNA is formed - this leaves the nucleus through the nucleus pore - then goes to the ribosome for translation

Question 39

What is the process of translation?

Answer 39

- mRNA read by ribosomes - tRNA molecules have an amino acid attached to them and line up in a row - have been coded by the codon - tRNA has an anticodon on the bottom, which is complementary to the mRNAs codons - mRNA is read in codons - a chain of amino acids forms - the frist tRNA molecule detaches and leaves the amino acids - theses then detach from the ribosome - the chain folds to form a protein

Question 40

What is an anticodon?

Answer 40

The triplet code found on the tRNA molecule which is complementary to the mRNA strand

Question 41

What is a mutation?

Answer 41

A rare random change in the base sequence of DNA

Question 42

Why do not all mutations cause a change in the protein made?

Answer 42

- some triplets code for the same amino acids - active site may not be changed - allele may be recessive - mutation in non coding DNA

Question 43

What is a stem cell?

Answer 43

An undifferentiated cell which can divide further and make more of itself or differentiate into a specialised cell

Question 44

What are the benefits of using adult stem cells?

Answer 44

They are already specialised There is no risk of the body rejecting them

Question 45

What are the benefits of embryonic stem cells?

Answer 45

They can be changed into any cell

Question 46

What is the issue with embryonic stem cells?

Answer 46

Can be unethical Body could reject