Biology Final Chapter 7

Question 1

3 building blocks of nucleotides

Answer 1

Sugar, phosphate, and base

Question 2

How do nucleotides come together to form DNA?

Answer 2

DNA is made up of two strands of subunits linked together in long chains. The phosphate groups of one nucleotide binds to the sugar group of another to form a chain of interlinked nucleotides. Bases are held together by hydrogen bonds.

Question 3

Complementary base pairing rules

Answer 3

Adenine binds with Thymine, Cytosine binds with Guanine

Question 4

How is DNA organized into Chromosomes

Answer 4

A chromosome is a single large DNA molecule wrapped around proteins. They exist in the nuclei of most eukaryotic cells.

Question 5

How do sex chromosomes determine a person’s biological gender?

Answer 5

We inherit 23 pairs of chromosomes each pair consisting of one from your father and mother. The 23rd chromosome pair determines a person’s sex. XX is female and XY is male.

Question 6

DNA replication

Answer 6

First the helix is unzipped, then DNA polymerase builds a new strand of DNA along each unzipped strand. Because each replicated molecule is made up of one original and one new strand, DNA replication is said to be semiconservative.

Question 7

Polymerase chain reaction (PCR)

Answer 7

A laboratory technique used to replicate, and thus amplify, a specific DNA segment. To a small sample of DNA, scientists add nucleotides, the DNA polymerase enzyme, and primers.

Question 8

Gel electrophoresis

Answer 8

A laboratory technique that separates fragments of DNA by size. Gel electrophoresis is used to create a DNA profile as it separates fragments of DNA into a pattern that is unique to each person.

Question 9

Short tandem repeats (STR)

Answer 9

block of repeated DNA sequences found at points along our chromosomes. These sequences are noncoding; the exact length of each STR varies from person to person. The differences in STR lengths are used to distinguish between individuals.