Genetics

Question 1

What is DNA

Answer 1

Comprised of of base pairs of nucleotides bound together by hydrogen bonds to create a double helix

Question 2

What are the four base pairs

Answer 2

Adenine with thymine
Guanine with cytosine

Question 3

What is transcription

Answer 3

this is the process of making mRNA

Question 4

What is step 1 in this mRNA process.Each gene is individually transcribed

Answer 4

step 1 - Beginning: Every gene contains a promoter that signals the start of the gene at the 5’ end. This is the starting place for the DNA’s separation.

Question 5

Step 2

Answer 5

Elongation - RNA polymerase uses one of the DNA strands as a template to create an RNA strand.

Question 6

Step 3

Answer 6

Termination - The RNA copy is finished and released from the RNA polymerase once the terminator DNA sequence is reached.

Question 7

What happens at the end of a 5’ end of a chain

Answer 7

The phosphate group of the chain’s first nucleotide sticks out at the 5’ end. This is referred to as the 5’ end of the sugar ring because the phosphate group is connected to its 5’ carbon.

Question 8

What happens at the end of a 3’ chain

Answer 8

The hydroxyl of the final nucleotide added to the chain is visible at the other end, known as the 3’ end. This is referred to as the 3’ end of the sugar ring because the hydroxyl group is joined to the 3’ carbon.

Question 9

What is genes

Answer 9

Gene shows on double helix in sections you get larger and smaller which the first expressed gene forms a protein

Question 10

What is protein coding

Answer 10

mRNA is converted into proteins via translation

Question 11

What happens in translation

Answer 11

During translation groups of three mRNA nucleotides (a codon) equate to one amino acid.There are 64 possible codons and 20 possible amino acids.Three codons cause protein synthesis to stop

Question 12

What happens if there is a mutation

Answer 12

Can cause incorrect amino acids or premature termination of the polypeptide chain

Question 13

What is proteins and there functions

Answer 13

As specified in the DNA code, proteins are polypeptides made of a chain of amino acids.
The great majority of biological activities are performed by proteins, which fold into three-dimensional structures to perform specialised tasks.

Question 14

What are the three types of mutation

Answer 14

Substitutions and Deletions and Insertion

Question 15

Why does a mutations occur

Answer 15

Mutations in the DNA sequence are likely to result in a change in the protein output of a gene and are the root cause of genetic disease.

Question 16

What is point mutations

Answer 16

Missense mutations- Sickle cell anaemia

Nonsense mutations- Many cancers

Question 17

What is Frameshift mutations

Answer 17

Insertion mutations- Fragile X syndrome

Deletion mutations- Prader-Willi syndrome

Question 18

What are Chromosomes

Answer 18

Are coiled up portions of DNA.
22 pairs of autosomes
2 allowsomes (sex chromosome)
XX female
XY male

Question 19

What is Mitosis

Answer 19

Produces two genetically identical daughter cells

Accepted as being comprised of five stages
Prophase
Metaphase
Anophase
Telophase
Cytokinesis

Question 20

What is Trisomy 21 - Down Syndrome

Answer 20

Three copies of chromosomes 21 (additional chromosmes)
Non Invasive Prenatal Testing blood test can be done for when a woman receives a higher chance result forT21

Question 21

Trisomy 13 - Patau Syndrome

Answer 21

Caused by an additional copy of chromosome 13 - but the copy is only present in some of the baby’s cells - mosaic

in partial form Patau’s syndrome, the baby has only inherited part of an extra copy of chromosome 13

Incidence 1 in 10,000 live births.Average survival age 2 ½ days

Question 22

Trisomy 18 - Edwards Syndrome

Answer 22

disorder in which babies are born with 3 copies of chromosome 18 instead of 2.Rate of occurrence Less than 10% of live babies survive the first year, with 95% of them dying in utero.

Question 23

Turners syndrome (XO)

Answer 23

condition that affects only females, results when one of the X chromosomes (sex chromosomes) is missing or partially missing. Turner syndrome can cause a variety of medical and developmental problems, including short height, failure of the ovaries to develop and heart defects.

Question 24

What is Mendelian Inheritance

Answer 24

Law of segregation
Law of independent assortment
Law of dominance

Question 25

What is Law of segregation

Answer 25

a trait relies on two alleales, one from each parent

Question 26

What is Law of independent assortment

Answer 26

Genes for different traits can segregate independently during the formation of gametes

Question 27

What is Law of dominance

Answer 27

Some alleles are dominant while others are recessive; an organism with at least one dominant allele will display the effect of the dominant allele.

Question 28

What is punnett square

Answer 28

Used to predict a specific phenotype in offspring
Require knowledge of both biological parents’ genotypes
Four possible outcomes, each with a 25% probability
Squares may be the same, making the probability of this outcome cumulative

Question 29

What is Huntingtons disease

Answer 29

Fatal condition causing the breakdown of nerve cells in the brain.