DNA + RNA (structure)

Question 1

Variation

Answer 1

Differences that occur within a species

Question 2

Heredity

Answer 2

The study of inheritance/ the study of how traits or characteristics are passed on from parents to offspring by means of genes.

Question 3

Gene expression

Answer 3

The precise way that information in the genetic code in a gene is decoded to make a protein like an enzyme. It is the expression of a gene that produces the traits that are inherited.
EG You might have the gene for being tall but if you do not get the right nutrients you will not be tall.
Characteristics= heredity + environment

Question 4

Species

Answer 4

a group of organisms that can interbreed and produce fertile offspring.

Question 5

Ratio of protein to DNA in Chromosomes

Answer 5

60% protein 40% DNA

Question 6

How is DNA held in this folded shape?

Answer 6

by histone proteins that wrap around the DNA and keep it coiled up in the nucleus.

Question 7

Introns and exons

Answer 7

exons - expressed
97% is junk dna [introns]

Question 8

What is the basic structure of DNA?

Answer 8

consists of 2 strands linked by pairs of bases.
DNA is twisted into a right hand twist to form a spiral called a double helix

Question 9

what are the 4 bases?

Answer 9

Adenine Thymine Guanine Cytosine

Question 10

Differences between RNA and DNA

Answer 10

Uracil instead of thymine
single stranded
Found in nucleus cytoplasm and ribosome. DNa just nucleus.

Question 11

Scientists who discovered the structure of DNA

Answer 11

James Watson and Francis Crick in 1953.
Bases on earlier research by Wilkins and Rosalind Franklin

Question 12

The make up of nucleotides

Answer 12

A phosphate group
A deoxyribose sugar
A nitrogenous base
Hydrogen bonds join the bases.

Question 13

What bases are pyrimidines

Answer 13

Cytosine and Thymine [single ringed molecules]

Question 14

What bases are purines?

Answer 14

Guanine and adenine [double ringed]

Question 15

DNA replication

Answer 15

During mitosis the DNA must make an exact copy of itself. Happens during interphase.

Question 16

DNA replication STEPS

Answer 16

1. Double helix unwinds.
2. An enzyme breaks the bond between the base pairs and held apart [helicase]
3. Free bases always present in the cytoplasm enter the nucleus and attach to the exposed base pairs [DNA polymerase]
4. DNA strand rewinds into a doible helix shape and everything is strengthened by DNA ligase.