What phenotypic ratio would you expect as a result of a test cross between a dihybrid organism and one that is homozygous recessive for alleles at two independent loci?
a. 3:1
b. 9:3:3:1
c. 1:1:1:1
d. 1:2:1
e. 9:4:2:1
Answer:
c. 1:1:1:1
Explanation:
When a heterozygous individual for two genes is test crossed with a double homozygous recessive individual, the progeny is obtained in 1:1:1:1 phenotypic ratio. This occurs as the heterozygous dominant individual forms four types of gametes in 1:1:1:1 ratio while the homozygous recessive individual would form only one type of gamete having one recessive allele for each gene.
For example, a test cross between TtRr (tall and red) and ttrr (short and white) would produce a progeny in following ratio=
1 tall, red: 1 tall, white: 1 short, red: 1 short, white
Here, T= tall, t= short, R= red, r= white
The common example of sublimation is shrinking of ice cubes that are not used in the freezer and conversion of dry ice rapidly into wispy clouds which vanish very soon
Scientists currently monitor underground movements, such as earthquakes and nuclear tests, using seismometers – instruments that measure the motion of those events at the Earth's surface.
Answer:
it is important for the skills to have hole thought the bone because it is used to relieve pressure on the brain when fluid, such as blood builds up and starts to compress bone tissues
Answer:
condensation
Explanation:
once evaporation occurs the water vapor rises and condenses into clouds when it hits the colder air higher in the atmosphere.