Topic 3

Question 1

What is transcription and protein synthesis

Answer 1

When RNA polymerase reaches a particular sequence of bases in the DNA it detaches and the production on pre-mRNA is complete

Question 2

What are 4 bases in a DNA called

Answer 2

Adenine
Guanine
Cytosine
Thymine

Question 3

What does Adenine go with

Answer 3

Thymine

Question 4

What does cytosine go with

Answer 4

Guanine

Question 5

What are animals that reproduce asexually

Answer 5

Amoeba, Hydra, water flees eg Daphnia

Question 6

What plants reproduce asexually

Answer 6

Strawberry’s and clover, succulents, potatoes

Question 7

What are the advantages of sexual reproduction

Answer 7

Produces offspring that are genetically different which is good if the environment changes so some offspring will be better suited for it

Question 8

What are disadvantages of sexual reproduction

Answer 8

Slower than asexual reproduction
Requires 2 mates- males and female
Eggs and spermicide need to be produced, dispersed, then to fuse during fertilisation

Question 9

What are the advantages of asexual reproduction

Answer 9

Much faster than sexual reproduction
Only 1 mate is needed
Can create lots in a short period of time

Question 10

What are the disadvantages of asexual reproduction

Answer 10

If all offspring are genetically identical they will all be affected negatively if the environment changes

Question 11

What is meiosis

Answer 11

It produces 4 genetically different sex cells
It allows variation to occur between individuals of the same species
2 haploid cells fusing at fertilisation to restore the diploid number

Question 12

What happens in the first stage of meiosis

Answer 12

There are 4 separate single chromosomes in 2 pairs but in their own

Question 13

Happens in stage 2 of meiosis

Answer 13

The single chromosomes fuse to make 2 pairs, each one has become a pair of sister chromosomes

Question 14

Genome

Answer 14

The haploid set of chromosomes in a gamete or microorganism or in each cell of a multicellular

Question 15

Polymer

Answer 15

A substance which had a molecular structure built up chiefly or completely from a large number of similar units bound together

Question 16

What is the backbone/ spine of the 2 strands in a DNA molecule made up of

Answer 16

Small phosphate and sugar that had a pentagon shape

Question 17

Why is a helix strand described as being double helix

Answer 17

A helix is a spiral structure and as DNA is 2 helixes it’s known as a double helix

Question 18

In mRNA what does Uracil replace

Answer 18

Thymine

Question 19

What does mRNA stand for

Answer 19

messenger
Ribose
Nucleiz
Acid

Question 20

Transcription

Answer 20

DNA is copied into mRNA in the nucleus
mRNA is a complementary single-strand of nucleotides
mRNA moves from the nucleus into the cytoplasm

Question 21

Translocation

Answer 21

mRNA is decoded when it attaches onto a ribosome in the cytoplasm
The mRNA codon is complementary to an anti-codon on a tRNA which has an amino acid attacked to it
The m & t matchup and their animo acids link to form a polypeptide chain, the beginning of protein

Question 22

Genetic variation

Answer 22

A Change in a base sequence can create a change in the sequence of animo acids. If the mutations fixed a new Allen has evolved

Question 23

Protein synthesis

Answer 23

The animo acid chain is called a polypeptide
The enzymes that attaches to DNA separates its strands: RNA polymerase
mRNA strands become attached to a ribosome which links together the substances carried by the tRNA
The mRNA strand codons match up to tRNA molecules

Question 24

What do triplets do

Answer 24

Tell DNA when to stop and make new lines of code