Topic4 Gene Mutatation And Meiosis

Question 1

What is Gene mutation and what are the two types? (AS)

Answer 1

Gene Mutation is the change in base sequence of DNA.

The two types are Substitution and Deletion mutation

Question 2

What is Substitution Mutation?
What is the affect?

Explain Everything

Answer 2

Substitution mutation is the substitution of one base for another changes AminoAcid which changes AminoAcid Sequence changing the primary and Tietary structure so changes protein structure and function

May not affect AminoAcid sequence due to degenerate nature of the genetic code.

Single AminoAcid change more likely to have a less of an effect

Question 3

What is deletion mutation?
What is the affect?

Answer 3

Deletion mutation is the deletion of base in a DNA sequence.

Causes a frame shift to the left.

Larger affect on amino acids as many codons are changed

Question 4

What is chromosomal Mutation?

Answer 4

Mutations in number of chromosome can arise by Chromosome non-disjunction in meiosis

Question 5

What causes chromosome mutations?

Answer 5

Non-disjunction is an error that occurs when chromosome are separated and divided resulting in Trisomy or Aneuploidy

Trisomy is extra copy of chromosome.

Aneuploidy missing copy or part of chromosome

Question 6

What is Trisomy?

Answer 6

Extra copy of chromosome

Question 7

What is Aneuploidy?

Answer 7

Missing copy or part of chromosome

Question 8

What is Meiosis?

What are Haploid cells?

What are Diploid cells?

(What do Meiosis create?)

Answer 8

Meiosis form of cell division that produces 4 daughter cells that are genetically different from each other.

Haploid cells are formed(n)
Diploid cells halved into Haploid(2n)

Meiosis produces gametes (Sex cells)

Question 9

What are the two ways meiosis creates genetic variation?

Answer 9

Crossing over and Independent Segregation

Question 10

What is crossing over?
When does it occur?
How does it occur?

Answer 10

Crossing over is sections of chromatids break and exchange sister chromatids on Homologous chromosomes.

Occurs during prophase 1

Homologous chromosome pair to form Bivalents
Section of Chromatid break and exchange sister chromatids on Homologous Chromosomes

Question 11

What is independent Segregation?

Answer 11

Homologous chromosome line up at the equator randomly.

Chromosome separate randomly
So therefore GAMETES Receive different combinations of maternal and paternal chromosomes

Question 12

what else increase Genetic Variation?

Answer 12

Random fertilisation gametes further increase genetics variation within species