Describe the relationships among genes, DNA, and traits.(1 point)

Question

Responses

Traits are determined by genes, which are composed of DNA.
Traits are determined by genes, which are composed of DNA.

Traits are made of genes, which are composed of DNA.
Traits are made of genes, which are composed of DNA.

Traits determine the DNA in genes.
Traits determine the DNA in genes.

Genes code for traits, which are composed of DNA.

Answer 1

The most accurate statement describing the relationships among genes, DNA, and traits is:

Traits are determined by genes, which are composed of DNA.

This statement correctly summarizes the hierarchy and function: genes (segments of DNA) provide the instructions for developing traits in an organism.

Answer 2

In mice, the gene for tail length has two alleles. A long tail is dominant to a short tail. If a long-tailed mouse that is heterozygous mates with a short-tailed mouse, what are the chances of having offspring with short tails?(1 point)
Responses

25%
25%

50%
50%

75%
75%

100%

Answer 3

To determine the chances of having offspring with short tails from a long-tailed mouse that is heterozygous (let's denote the alleles as L for long tail and l for short tail) and a short-tailed mouse (which must be homozygous recessive, ll), we can set up a simple Punnett square.

The genotypes are as follows:

• Heterozygous long-tailed mouse: Ll
• Short-tailed mouse: ll

The possible allele combinations from these parents are:

1. From the heterozygous parent (Ll):

   • L (dominant for long tail)
   • l (recessive for short tail)

2. From the homozygous recessive parent (ll):

   • l (both alleles)

Now, filling out the Punnett square:

     l    |    l
  -----------------
L |   Ll   |   Ll   |  (long tail)
  -----------------
l |   ll   |   ll   |  (short tail)

From this, we can see that there are:

• 2 Ll (long-tailed)
• 2 ll (short-tailed)

Thus, the ratio of offspring is 2 long-tailed (Ll) to 2 short-tailed (ll), which can be simplified to 1:1.

Therefore, the chances of having offspring with short tails (ll) are 50%.

Answer 4

What is meant by a phenotype ratio in a Punnett square?(1 point)
Responses

the fraction of possible offspring that contain a certain allele in their genes
the fraction of possible offspring that contain a certain allele in their genes

the number of alleles in possible offspring
the number of alleles in possible offspring

the number of genes that are possible in offspring
the number of genes that are possible in offspring

the fraction of possible offspring that can be observed to have a trait

Answer 5

The correct response is:

the fraction of possible offspring that can be observed to have a trait.

A phenotype ratio in a Punnett square represents the relative frequencies of different observable traits (phenotypes) in the offspring resulting from a genetic cross.

Answer 6

Tysha is conducting gel electrophoresis at home. She has finished creating her gel and has put it in the plastic box she is using. What should she do next? (1 point)
Responses

Fill the box with electrolyte solution.
Fill the box with electrolyte solution.

Mix agar-agar with a sodium bicarbonate solution.
Mix agar-agar with a sodium bicarbonate solution.

Connect the power source.
Connect the power source.

Load the sample into the wells.

Answer 7

The correct next step for Tysha after creating her gel and placing it in the box is:

Fill the box with electrolyte solution.

Before loading the samples into the wells, the gel should be submerged in an electrolyte solution to allow for the conduction of electricity during the gel electrophoresis process.