BSC1005 CHAPTER 7-10 FINAL STUDY GUIDE

monohybrid cross

a cross in which only one characteristic is tracked

Who discovered that DNA contains equal amounts of adenine and thymine; guanine and cytosine?

Erwin Chargaff

Who produced a X-ray diffraction pattern of DNA, revealing a symmetrical organization of repeating building blocks?

Rosalind Franklin & Maurice Wilkins

Who put together discoveries made by others into a 3D model of DNA?

James Watson & Francis Crick

DNA is in the shape of a _____.

Twisted ladder (Double Helix)

DNA RAILS are _____ joined by ______.

alternating sugar/deoxyribose & phosphate units, covalent bonds

DNA RUNGS are _____ joined by ______.

A-T & G-C, hydrogen bonds

DNA strands are oriented in _______.

opposite directions (antiparallel)

A only binds with ___.

T

G only binds with ___.

C

Unlike DNA, RNA is generally _____.

single stranded

DNA stores _____________.

RNA & protein encoding info

DNA transfers _________.

information to next generation cells

RNA carries _____.

protein encoding information

RNA helps to ______.

make proteins & catalyze some reactions

RNA has ___ instead of Thymine.

Uracil

RNA has ____ sugar.

ribose

DNA has ____ sugar.

deoxyribose

mRNA (messenger RNA)

carries instructions to make a specific protein (transcription & translation)

rRNA (ribosomal RNA)

combines with proteins to form ribosome, the sites of protein synthesis(translation)

tRNA (transfer RNA)

carries specific amino acid to ribosome (translation)

Gene

A segment of DNA on a chromosome that codes for a specific trait

transcription factors

a regulatory protein that binds to DNA and affects transcription of specific genes

Silent mutation

alters a base but does not change the amino acid (no effect)

Missense mutation

alters a base that specifies a different amino acid

Nonsense mutation

alters a base that specifies one of the three stop codons

Frameshift mutation

addition or deletion of bases by any number other than a multiple of 3

Nonsense mutation example

Cystic fibrosis

Missense mutation example

sickle cell anemia

Frameshift mutation example

non-functional protein

Role of mitosis in unicellular organisms

reproduction

Role of mitosis in multicellular organisms

development, repair, and regeneration

Apoptosis

programmed cell death

Apoptosis helps weed out ______.

harmful cells

Apoptosis helps to _____.

carve out functional structures (fingers)

DNA is replicated during:

S phase of interphase

Mitosis stage 1

prophase

Mitosis stage 2

metaphase

Mitosis stage 3

anaphase

Mitosis stage 4

telophase

Prophase

Chromosomes become visible, nuclear envelop dissolves, spindle forms

Metaphase

Spindle apparatus aligns chromosomes along the cell's equator

Anaphase

Centromeres split, the chromosomes separate and move to opposite ends of the cell

Telophase

Spindle apparatus disassembles, chromosomes begin to unwind, nuclear envelope reforms

Cytokinesis in plant cells

divide from inside out using a cell plate in middle of cell

Cytokinesis in animal cells

cleavage furrow forms and cell pinches in two

Which cell cycle checkpoint is most important?

G1

What advantage does sexual reproduction have over asexual reproduction?

genetic diversity

haploid cell

a cell with a single chromosome set

diploid cell

a cell with two sets of chromosomes

homologous pair

each of the 23 pairs of human chromosomes

sister chromatids

joined copies of the original chromosome

In what way does sexual reproduction and meiosis create genetic variation within a population?

crossing over

In what way does sexual reproduction and meiosis create genetic variation within a population?

independent assortment

In what way does sexual reproduction and meiosis create genetic variation within a population?

random fertilization

What problem does meiosis solve for sexually-reproducing organisms?

maintaining the correct number of chromosomes from generation to generation

Law of independent assortment

The segregation of alleles for one gene is independent of the segregation of alleles for another gene

Law of Segregation

2 alleles of each gene are packaged into separate gametes

dihybrid cross

a cross in which two characteristics are tracked

What are two examples of X-linked recessive disorders in humans?

hemophilia, colorblindness