Chapter 4: Genetics & Cellular Funcution

Question 1

Deoxyribonucleic Acid (DNA)

Answer 1

Double helix
*Spiral staicase
Uniform diameter- 2nm
*length varies

Polymer of nucleotides

Question 2

Components of DNA

BPD

Answer 2

Bases

• Purines (adenine, guanine)
• Pyrimadines (cytosine, thyamine)

Phosphate Group

Deoxyribose (sugar)

Question 3

Chromatin

Answer 3

Material that make up chromosomes of organisms

Consists of: RNA, DNA, and proteins

• 46 chromosomes
• 6 ft thread packed in cell nucleus

Question 4

Histones

Answer 4

Proteins crucial for DNA packing

• Group of 8 molecules
• DNA winds around

Question 5

Nucleosome

Answer 5

Basic repeating subunits of chromatin

Consist of:

• Histone cluster with DNA around
• Linker DNA- short DNA connecting core particles

Chromatin thrown into complex, irregular loops and coils

Question 6

Chromosome

Answer 6

A doubled rod of condensed chromatin; contains DNA that carries genetic information.

Question 7

Chromatids

Answer 7

one of two identical “sister” parts of a duplicated chromosome

Question 8

Centromere

Answer 8

pinched area where the chromatids of a chromosome are attached

Question 9

Kinetochore

Answer 9

Protein plaque on the sides of the centromere

Question 10

Ribonucleic Acid (RNA)

Components? RU
Types?

Answer 10

Single chain- shorter DNA
Interrupts DNA to Synthesize protein
Works in Cytoplasm

Components:

• Ribose (sugar)
• Uracil

Types: mRNA, tRNA, rRNA

Question 11

Gene

Answer 11

Individual segment of DNA that codes for a specific protein

Question 12

Genome

Answer 12

All genes of one person

Question 13

Genetic Code

Answer 13

System that enables these four nucleotides (A, T, C, G) to cods for the amino acids sequence of all proteins

*Minimum code to symbolize 20 amino acid= 3 NT per AA

Question 14

Base Triplet

Answer 14

Sequence of 3 DNA nucleotides that stand for one amino acid

Question 15

Codon

Answer 15

The 3-base sequence in mRNA

*65 possible to rep for 20 Amino Acids

Question 16

Exons

Answer 16

“Sense” portions of the immature RNA

* Will translate to proteins

Question 17

Introns

Answer 17

“Nonsense” portions of the immature RNA

*Must be removed before translation

Question 18

Alternative Splicing

Answer 18

Removing the introns by enzymes and splicing the exons together into functional RNA molecules

Question 19

Translation

3 Stages? Tie

Answer 19

The process that converts the language of nucleotides into language or amino acids

3 Stages:

• Termination
• Initiation
• Elongation

Question 20

Chaperone Proteins

Answer 20

Older proteins that pick up new proteins and guide them into folding into the proper shape

Question 21

Mutations & How You Obtain Them

Answer 21

Changes in DNA structure due to replication errors or environmental factors

ex: radiation, viruses, chemicals

Question 22

Effects of Mutations

Answer 22

Some have no ill effects

Others kill the cell, turn into cancerous, or cause genetic defects in future generations

Question 23

4 Main Phases of the Cell Cycle

Answer 23

G1: first gap phase
S: synthesis phase(DNA replication)
G2: second gap phase
M: mitotic phase( cell division)

Question 24

G1: Frist Gap Phase

Answer 24

interval between cell division and DNA replication

*preforms normal functions

Question 25

S: Synthesis Phase

Answer 25

DNA replication

Question 26

G2: Second Gap Phase

Answer 26

Interval between DNA replication and cell division

Question 27

M: Mitotic Phase

Answer 27

Cell division

Question 28

Mitosis

Answer 28

A body cell doubles its DNA and then divides to produce two genetically identical daughter cells

Question 29

4 Stages of Mitosis PMAT

Answer 29

Prophase Metaphase Anaphase Telophase

Question 30

Prophase

Answer 30

* Nuclear envelope disintegrates * Chromosomes formed * Spindel fibers are created

Question 31

Metaphase

Answer 31

* Chromosomes align on the cell equator | * Spindle fibers attach to the kinetochores

Question 32

Anaphase

Answer 32

* activation of cleaving enzymes | * spindle fibers pull chromatids to polar sides of the cell

Question 33

Telophase

Answer 33

* chromatids cluster on both sides an uncoil * nuclear envelope formed * spindle fibers disintegrate

Question 34

Cytokinesis

Answer 34

Division of cytoplasm into two cells

Question 35

Meiosis

Answer 35

Production of four gametes(haploid cells), each with only half DNA of the diploid cells

Question 36

Heredity

Answer 36

Transmission of genetic characteristics from parent to offspring

Question 37

Karyotype

Answer 37

Chart of our 46 chromosomes laid out by size

Question 38

Diploid(2n)

Answer 38

Any cell with 23 pairs of chromosomes (somatic cells)

Question 39

Haploid(n)

Answer 39

Contain half as many chromosomes as somatic cells (germ cells) ex: sperm and egg cells

Question 40

Locus

Answer 40

Location of a particular gene on a chromosome

Question 41

Alleles

Answer 41

Different forms of a gene at same locus on two homologous chromosomes

Question 42

Dominant

Answer 42

Capital Letter * Masks the effect of any recessive allele present * Produce protein responsable for visible trait

Question 43

Recessive

Answer 43

Lower Case Letter * Expressed only if on both homologous chromosomes * No dominant allele at locus

Question 44

Genotype

Answer 44

Alleles that an individual possesses for a particular trait

Question 45

Homozygous Allele

Answer 45

Two identical alleles for a trait

Question 46

Heterozygous Allele

Answer 46

Different alleles for that gene

Question 47

Phenotype

Answer 47

Observable Trait

Question 48

Carrier

Answer 48

Carry the recessive allele but do not express it

Question 49

Gene Pool

Answer 49

Genetic make up of a whole population

Question 50

Codominance

Answer 50

Both alleles are equally dominant ex: blood type, AB (both are expressed)

Question 51

Incomplete Dominance

Answer 51

Phenotype intermediate between traits each allele would have produced alone ex: skin tone

Question 52

Polygenic Inheritance

Answer 52

Genes at two or more loci contribute to a single phenotype | ex:eye color

Question 53

Pleiotropy

Answer 53

One gene produces multiple phenotypic effects

Question 54

Sex Linked Traits

Answer 54

carried on the X and Y chromosomes Inherited by one sex vs. the others ex: color blindness