Gene Linkage

Causes genes to not segregate independently. Causes genes to be more likely to be inherited together. Represents an exception to Mendel's Law of Independent assortment.

• Gene linkage

• Epistasis

• Polygenic traits

• Codominance

Crossingover occurs between

• Homologous Non sisters

• Homologous Sisters

• Between both homologous sisters and non sisters

• Occurs between different crhomosomes

Tags

NGSS.HS-LS3-2

How many genes can be mapped with the help of a double crossover?

• 3

• 2

• 4

• either 2 or 3

A segment of DNA that codes for a trait

• gene

• centromere

• chromosome

• chromatid

Tags

NGSS.HS-LS3-1

Why is a test cross always performed when we need to map the gene distance? (2 marks)

How many progeny will be have if we have 3 genes that are being mapped?

• 9

• 8

• 4

• 6

If the distance between A/B is 0.12 mu and gene C is on the opposite side of A with respect to B at a distance of 0.23 mu, Which is the central gene in this map

• A

• B

• C

• Data insufficient

If the distance between A/B is 0.12 mu and gene C is on the opposite side of A with respect to B at a distance of 0.23 mu, What is the order of the gene linkage map

• A - B - C

• C - A - B

• both A - B - C and C - B - A are possible

• The linkage map cannot be detemined as the ratio is not 1:1

• A - C - B

If the distance between A/B is 0.12 mu and gene C is on the opposite side of A with respect to B at a distance of 0.23 mu, then distance A/C is (choose the most accurate option)

• equal to 0.35 mu

• greater than 0.35 mu

• lesser than 0.35 mu

• equal to or lesser than 0.35 mu

• equal to or greater than 0.35 mu

A cross is made between vermilion (v), scute (sc), yellow body (y) fly and a wild type fly. The F1 is test crossed and the F2 progeny are as follows: + + + = 489, v sc y = 470, + sc y = 210, v + + = 218, + + y = 10, v sc + = 6, + sc + = 156, v + y = 141. What is the COC in this cross (1 mk)

• 0.01875

• 0.2856

• 0.1875

• 1.562

Tags

NGSS.HS-LS3-3