DNA and Genetics- S C I E N C E

Question 1

Chromosome

Answer 1

Chromosomes are long chains of DNA molecules that contain part or all of the genetic material of an organism. Unit of inheritance- DNA wrapped around protein. 23 each parent- 46 in total

Question 2

Structure of DNA nucleotide

Answer 2

Phosphate, sugar, nitrogen base

Question 3

Structure of DNA polymer

Answer 3

Double helix- DNA is a polymer made from 4 different monomers called nucleotides

Question 4

Base pairing rule

Answer 4

Bases form weak hydrogen bonds with bases on the complementary DNA strand. A bonds with T, G bonds with C

Question 5

DNA

Answer 5

DNA is the fundamental molecule that carries the genetic instructions of all living organisms. Found in nucleus of cells but also present in mitochondria and chloroplasts.
Carries the information for cells to make proteins and when to make them

Question 6

Difference between DNA and RNA

Answer 6

DNA replicates and stores genetic information
RNA converts genetic information to build proteins. DNA is double stranded, RNA is single stranded

Question 7

Mitosis

Answer 7

Mitosis is the process of cell division that produces two genetically identical daughter cells from one mother cell. Occurs in somatic (body) cells

Question 8

Meiosis

Answer 8

Used to make sex cells- egg and sperm. Sex cells have 1 copy of each chromosome. Meiosis produces 4 non-identical daughter cells

Question 9

Diploid

Answer 9

Two copies (2n)
Somatic cells
Exception is gametes

Question 10

Haploid

Answer 10

1 copy (n)
Sex cells

Question 11

Transcription

Answer 11

RNA polymerase enzyme in the nucleus uses the template DNA strand to make a complementary mRNA strand

Question 12

Translation

Answer 12

Ribosomes use mRNA to make a polypeptide chain (protein). Start codon is AUG and amino acids are added using the genetic code until a stop codon is reached

Question 13

Mutation

Answer 13

Change in DNA sequence caused by a ‘mistake’ during DNA replication
Potential change in protein

Question 14

Gene

Answer 14

DNA sequence that has the information for one protein
Some mutations cause changes in protein sequence and causes the organism to be different (mutant)

Question 15

Point mutation

Answer 15

substitution- swapping one base for another

Question 16

Silent mutation

Answer 16

substitution- no effect

Question 17

substitution mutation

Answer 17

different amino acid

Question 18

premature stop

Answer 18

shorter protein (non functional)- substitution

Question 19

Frame shift mutation

Answer 19

adding or removing bases

Question 20

codon deletion/insertion

Answer 20

protein with additional or missing amino acids

Question 21

Frame shift mutation (effects)

Answer 21

many different amino acids (after the frame shift)

Question 22

Codon

Answer 22

3 bases in a row

Question 23

Allele

Answer 23

Form of a gene that can be symbolised by capital or lower case letter

Question 24

Trait

Answer 24

characteristic that is inherited

Question 25

genotype

Answer 25

alleles that an individual has- only 3 possibilities

Question 26

phenotype

Answer 26

description of trait in an individual eg. colour

Question 27

heterozygous

Answer 27

alleles that are different

Question 28

homozygous

Answer 28

if two alleles are the same, ‘purebred’

Question 29

dominant

Answer 29

dominant genotype-capital letter. Only needs 1

Question 30

Recessive

Answer 30

needs both genes

Question 31

co-dominant

Answer 31

when two different alleles of the same gene are expressed to an equal degree within an organism 🐮

Question 32

sex-linked

Answer 32

refers to traits or disorders influenced by genes on the X-chromosome

Question 33

autosomal

Answer 33

non-sex chromosome