Biology Test Review- DNA & Genetics

for the test

Who is the father of genetics?

Gregor Mendel

What is a phenotype?

physical characteristics of an organism

What is a genotype?

genetic makeup

What is homozygous?

organisms that have two identical alleles for a particular trait

What is heterozygous?

two different alleles

What is a monohybrid cross?

a cross that involves hybrids for a single trait

What is a dyhybrid cross?

a cross that examines the inheritance of two different traits

What is a recessive allele

lower case letter(aa)

What is a dominant allele?

Upper case and if there is an uppercase with a lower case it masks the lowercase making the whole allele dominant. (AA/Aa)

What are the Mendelian Genetics?

Principle of Dominance and Recessiveness, Principle of Segregation, and Principle of Independent Assortment.

What is principle of dominance and recessiveness?

Some alleles are dominant and others are recessive. A dominant allele can cover up or mask a recessive allele.

What is the principle of segregation?

For each gene, an organism receives one allele from each parent. The alleles separate from each other when reproductive cells are formed.

What is the principle of independent assortment?

genes for different traits can segregate independently during the formation of gametes

What is codominance?

both alleles contribute to the phenotype(a pink flower is c^W and a blue flower is c^B so the codominance will be C^WC^B)

sex-linked traits

traits that are inherited with sex chromosomes(so some traits may be specific to your sex)

What is a pedigree?

a diagram that shows a recurring genetic trait through several generations.

What is DNA

deoxyribonucleic acid, double-stranded, genetic info, made up of nucleotides.

What does each DNA contain?

5-carbon sugar, a nitrogen base(A

What are the nitrogen bases and how do they bond?

Adenine bonds to Thymine, Cytosine bonds to Guanine.

What are chromosomes made of?

DNA and proteins

WHEN IT SAYS LADDER FOR DNA STRUCTURE ON A QUIZ/TEST IT DOES NOT MEAN A LITERAL LADDER

IT MEANS DIS GUY

What are purines?

Adenine and Guanine

What are pyrimidines?

cytosine, thymine, uracil(only for RNA)

What bonds guanine to cytosine?

Three hydrogen bonds.

What bonds Adenine and Thymine?

2 hydrogen bonds

What is the beginning, beginning of DNA replication?

DNA needs to be copied before it can divide so it is replicated in the S Phase(Synthesis) of Interphase.

what is helicase and topoisomerase?

Helicase unzips and topoisomerase unwinds, and then the replication begins at the replication fork.

What is the 5 replication enzymes in order?

Helicase, Topoisomerase, RNA Primase, DNA Polymerase, Ligase

What is the leading strand?

The strand where replication moves towards the replication fork (follows helicase), 5' to 3' and is at the top.

What is the lagging strand?

The strand where DNA replication moves away from the replication fork, 3' to 5' and is at the bottom.

What is the Okazaki fragment?

short DNA fragments on the lagging strand, make fragments on the lagging strands.

What is RNA Primase?

Before a DNA strand forms, RNA Primer must be present to add the nucleotides. It synthesizes the RNA Primer and then DNA Polymerase adds the new nucleotides.

What is DNA polymerase?

Enzymes bond nucleotides together and can only do it at the 3' end so it is built in a 5' to 3' direction.

What is DNA ligase?

an enzyme that seals the bonds between restriction fragments

What does OO mean in blood?

Means it Rh -

What is bidirectional replication?

It goes in two directions from the origin in replication

What does discontinuous mean?

Means lagging strands is synthesized in short fragments(Okazaki fragments), they are later combine together by DNA Ligase

Why is DNA replication called semi-conservative?

DNA is a double-stranded molecule so a strand from another DNA is used for the new strand of the DNA making it double-stranded. When DNA is copied and separated new nucleotides come and match the two separated strands.