mastering biology 5&6

If an organism has two non-identical versions of a gene, the one that is expressed in the organism is called the _________ allele.

Dominant

Why are linked genes inherited as a set rather than independently?

Linked genes are located near each other on the same chromosomes, so they tend to move together.

RNA usually consists of a single________ strand

Polynucleotide

Fur color in rabbits is controlled by multiple alleles. What does this mean?

Rabbit fur color is controlled by a single gene, but there are multiple versions of that gene.

PCR is used to copy just a relatively small region of DNA, not the entire genome. How do researchers specifically target the region of interest?

They use two primers, each about 15 to 20 nucleotides long, that flank the region of interest.

What do we call a genetic cross that follows two separate characters, such as pea seed color and pea seed shape?

a dihybrid cross

If you wanted to visualize the location of a particular gene on a particular chromosome, you might use __________.

a fluorescent nucleotide probe

What is a carrier?

an individual who is heterozygous for a particular recessive trait

Duplication of the chromosomes by a cell occurs __________

before a cell divides

During DNA replication, __________.

each of the two daughter DNA molecules contains one strand from the original DNA molecule and one newly synthesized strand

Mendel's Law of Independent Assortment states that __________.

each pair of alleles segregates independently of the other pairs of alleles

Random orientation of homologous pairs of chromosomes during meiosis I results in alternative arrangements that contribute to genetic variation in offspring. This is called __________.

independent assortment

Crossing over happens during __________

meiosis

The monomers of nucleic acids consist of a phosphate group, a five-carbon sugar, and a

nitrogen base

A researcher has identified a mutation in a gene for a protein that is usually 636 amino acids long. The protein product of the mutated gene is only 20 amino acids long. This mutation is probably a __________.

nonsense mutation

Nucleic acids are polymers of

nucleotides

In animals, meiosis __________.

produces four gamete cells

If an organism has two non-identical versions of a gene, the one that is not expressed in the organism is called the __________ allele.

recessive

A __________ cuts DNA only at specific nucleotide sequences.

restriction enzyme

Which of the following mutations is LEAST likely to result in harmful changes to cells?

silent mutation

__________ are linked together at the centromere

sister chromatids

A polynucleotide has a repeating ________ backbone

sugar phospate

tRNA molecules work to _____

translate mRNA to produce a specific amino acid sequence

Like mitosis, meiosis involves duplication of the chromosomes before division starts. However, there are __________ rounds of cell division during meiosis and __________ during mitosis.

two; one