3.4.1 DNA, genes and chromosomes

Question 1

How is DNA stored in a prokaryotic cell?

Answer 1

Short and Circular
Condeses to fit into the cell by supercoiling

Question 2

How is DNA stored in a eukaryotic cell?

Answer 2

Contains linear DNA that exits as chromosomes

Question 3

When are chromosomes visible?

Answer 3

During cell division

Question 4

What is the process of supercoiling in Eukaryotic cells?

Answer 4

A DNA molecule combines with a histone protein to form DNA-Histone complex whjich then get tightly coiled to form loops which become chromosomes

Question 5

What is a chromatid?

Answer 5

Half of the duplicated chromosome

Question 6

What are sister chromatids?

Answer 6

Two chromatids that are joined together by a centromere

Question 7

What are telomeres?

Answer 7

Telomeres are found at the end of a chomatid and are protective strucutres that seal the ends of each chromatid

Question 8

Other than the nucleus where can DNA be found?

Answer 8

Chloroplast (cpRNA)
Mitochondria (mtRNA)

Question 9

What are genes?

Answer 9

Genes code for a sequence of bases which can code for either a polypeptide or functional RNA

Question 10

What are the three main types of functional RNA?

Answer 10

rRNA (Ribosomal RNA)
mRNA (Mitochondria RNA)
tRNA (Transfer RNA)

Question 11

What does the order of Nucleotides determine?

Answer 11

The amino acid in a particular polypeptide sequence

Question 12

What is a group of 3 nucleotides called?

Answer 12

Codon or triplet code

Question 13

How many different amino acids are there?

Answer 13

20

Question 14

What is the particular position of a gene in a section of DNA?

Answer 14

Locus

Question 15

What is an allele?

Answer 15

Each gene can exist in more than one way and this is known as an allele

Question 16

What are Homologous chromosomes?

Answer 16

Matching pairs of choromes where one is from your mother and the other from your father

Question 17

What are the three properties of genetic code?

Answer 17

Degenerate
Universal
Non-Overlapping

Question 18

What is meant by the term degenerate?

Answer 18

Each amino acid is coded by more than one codon

Question 19

What is meant by the term Universal?

Answer 19

Each codon codes for the same amino acid in every organism

Question 20

What is meant by the term Non-overlapping?

Answer 20

Each base is only read once

Question 21

What are introns?

Answer 21

Introns are parts of the DNA which don’t code for amino acids

Question 22

What are exons?

Answer 22

Exons are parts of FNA which do code for amino acids