Genetics Heredity Unit

What is the purpose of DNA?

• manufactures proteins

• reduces activation energy

• stores hereditary information

• to aid in facilitated diffusion

According to the Punnett square: B represents the dominant gene for blue feathers and b represents the recessive gene for red feathers. Two heterozygous birds have one offspring. What percent chance does it have for red feathers?

• 0%

• 25%

• 75%

• 100%

In rabbits, the allele for black fur, B, is dominant over the allele for brown fur, b.

Calculate the probability of a homozygous dominant (BB) offspring resulting from a cross between two parents with the genotype Bb

• $\frac{1}{100}$

• $\frac{1}{2}$

• $\frac{1}{4}$

• $\frac{7}{10}$

An organism with 32 chromosomes in each body cell will produce sex cells with __________ chromosomes.

• 18

• 32

• 64

• 12

DNA fingerprinting would most likely be used to:

• identify human age and lifespan

• determine genetic relationships

• diagnose different types of cancer

• create genetically-identical species

The Punnett square shown presents a cross between two piranha. Both parents have large teeth.

According to the chart, which combination describes the offspring expected from the cross?

• 50% large-toothed and 50% small-toothed

• 75% small-toothed and 25% large-toothed

• 75% large-toothed and 25% small-toothed

• 100% large-toothed

What situation is an example of artificial selection?

• Female bluegill fish prefer to lay their eggs in the nests of larger male fish.

• Albino deer or rabbits have a low survival rate in nature, because it is easy for predators to spot them.

• Penguins with higher body fat tend to survive nesting in the Antarctic winter, while leaner penguins often die.

• More African elephants today naturally lack tusks compared to the elephant populations 100 years ago, because big game hunters sought elephants for ivory.

In piranha, fish with large teeth represent the dominant trait. Because the dominant trait masks the recessive trait, in a population of 1,000 piranhas, all with large teeth, we could expect about ________of the next generation of fish to have small teeth.

• 0%

• 25%

• 50%

• 75%

The process of ____________ increases genetic variability as it produces gametes for sexual reproduction.

• conjugation

• mitosis

• meiosis

• replication

In some instances, humans breed animals that are close relatives to produce desired traits. This is called

• cloning

• random mating

• artificial selection

• inbreeding