Module 3

Question 1

What are histones? & what is their function

Answer 1

a protein involved with gene regulation; they alter how much the DNA is exposed and how much it is coiled as well as package the DNA into chromosomes.

Question 2

Genome?

Answer 2

an organism’s entire DNA

Question 3

What is each coil of DNA called?

Answer 3

a nucleosome

Question 4

Cell division is..?

Answer 4

the process of a cell splitting into 2 identical daughter cells

Question 5

What does cell division provide for a single-celled organism?

Answer 5

A means of asexual reproduction for single-celled organisms

Question 6

What does cell division provide for a multi-celled organism?

Answer 6

1. Growth and Development for multi-celled organisms
2. A way to repair damaged tissue

Question 7

What are the 2 major parts of Cell division?

Answer 7

Interphase and Mitotic phase

Question 8

What ultimately happens during Interphase?

Answer 8

Where a cell’s chromosomes duplicated and cell parts are made

Question 9

What ultimately happens during the Mitotic phase?

Answer 9

Cell division

Question 10

What keeps the arms of sister chromatids together?

Answer 10

Cohesions

Question 11

What phase does the cell spend the most time in?

Answer 11

Interphase

Question 12

What are the sub stages of Interphase?

Answer 12

G1, S, and G2

Question 13

What takes place in G1 subphase?

Answer 13

-the cell size increases
-increase in the # of ribosomes and mitochondria

Question 14

What takes place in the S subphase?

Answer 14

-DNA replication
-Histones replicate

Question 15

Why is there an increase of ribosomes and mitochondria in the G1 sub phase?

Answer 15

To provide the ATP and proteins needed to replicate the DNA and Histones

Question 16

What takes place in the G2 sub phase?

Answer 16

• the cell further increases in size
  -final preparations for division
  -end up with 2 copies of DNA

Question 17

What sub phases does the Mitotic phase consist of?

Answer 17

Mitosis and, optionally Cytokinesis

Question 18

What are the phases of Mitosis in order?

Answer 18

1. Prophase
   2.Metaphase
2. Anaphase
3. Telophase

Question 19

How are cohesions separated?

Answer 19

by an enzyme called separase

Question 20

How do microtubules pull the sister chromatids apart?

Answer 20

they shorten themselves by depolymerizing at the kinetochore ends and pull the sister chromatids apart as they shorten

Question 21

at what end do the microtubules shorten?

Answer 21

at the end at which they’ve grabbed the chromosome

Question 22

What state do adults cells enter when they lose the capacity to divide?

Answer 22

G0 state

Question 23

Can all cells switch from in and out of G0 state?

Answer 23

No, most but not all
ex: nerve and muscle cells

Question 24

Binary fission?

Answer 24

how prokaryotic organisms divide asexually

Question 25

What are autosomes?

Answer 25

chromosomes that are the same in male and female

Question 26

What are haploids?

Answer 26

a cell that contains one set of chromosomes (n)-23

Question 27

What are diploids?

Answer 27

a cell that contains 2 sets of chromosomes (2n)-46

Question 28

What are autosomal recessive disorders?

Answer 28

Disorders that requires both alleles to be inherited from parents for the trait to be expressed

Question 29

What are Autosomal dominant disorders?

Answer 29

Disorders that take 1 out of 2 alleles to be inherited for the trait to be expressed

Question 30

Sex-Linked traits

Answer 30

Traits that are usually inherited from the female

Question 31

Why are sex-linked almost always traits carried/passed on from the female?

Answer 31

b/c males only give a Y and only have one X, while females have 2 X's, therefore more often than not we will see the sex linked trait being passed on by the X

Question 32

What kinds of mutations do we see?

Answer 32

- some beneficial; evolution - some neutral; blue eyes - some harmful; cancer

Question 33

what kind of mutation effect do we usually see?

Answer 33

Neutral mutations are the most common b/c of the probability, we have much more "junk DNA"

Question 34

What kinds of "breaks" can we see in chromosomes sequence?

Answer 34

1. Deletion 2.Duplication 3. Inversion 4. Translocation

Question 35

What is nondisjunction?

Answer 35

when a pair of chromatids do not separate during mitosis or meiosis?

Question 36

Aneuploidy?

Answer 36

chromosomal aberrations-chromosomes present in extra copies or deficient of

Question 37

Where are odd numbers of chromosomes usually caused

Answer 37

from problems in meiosis

Question 38

Why do somatic chromosome abnormalities occur?

Answer 38

most of the time they occur when there is a extra copy of autosomes

Question 39

what are the results of somatic chromosome abnormalities?

Answer 39

Almost always disasterous, offspring will either not be born alive or not live to adulthood

Question 40

Trisomy?

Answer 40

a chromosomal condition that resulted from an extra chromosome in some or all of the body's cells

Question 41

Trisomy 13?

Answer 41

Patau's syndrome- death few days after birth

Question 42

Trisomy 18?

Answer 42

Edward's syndrome- death usually in a few months and affects almost every body organ

Question 43

Trisomy 21?

Answer 43

Down syndrome- chances increase the older the parent

Question 44

How do you detect chromosomal abnormalities?

Answer 44

performing a karyotype

Question 45

Ways to perform a karyotype?

Answer 45

- aminocentesis -CVS (chorionic villus sampling)

Question 46

Which is more severe; Nondisjunction w/ the sex chromosomes or nondisjunction w/ the autosomes

Answer 46

Autosomes

Question 47

Who did modern genetics began with?

Answer 47

Gregor Mendel

Question 48

Alleles?

Answer 48

an alternate molecular form of a gene

Question 49

Phenotype?

Answer 49

the way an organism's physical appearance is expressed

Question 50

Genotype?

Answer 50

an organisms genetic makeup

Question 51

What is a progeny?

Answer 51

Offspring

Question 52

Monohybrid Cross?

Answer 52

the offspring of 2 individuals that differ based off one gene/trait inherited

Question 53

What is incomplete dominance in genetics?

Answer 53

Whenever there is not dominant allele so they merge

Question 54

Codominance in genetics?

Answer 54

when we have more than one dominant allele ex: blood typing

Question 55

Epistasis?

Answer 55

when an unrelated gene modifies the phenotype expression of another gene

Question 56

Pleiotropy?

Answer 56

when one gene alters the expression of 2 of more traits

Question 57

Polygenic Inheritance?

Answer 57

when a trait is controlled by multiple genes and/or influenced by the environment ex: intelligence, height, and skin color

Question 58

What is Mendel's Theory of Independent Assortment?

Answer 58

that alleles of different genes are inherited independently during sexual reproduction. This means that the allele a gamete receives for one gene does not affect the allele it receives for another gene. As a result, every possible combination of alleles for each gene is equally likely to occur.

Question 59

Dihybrid cross?

Answer 59

a mating experiment between two organisms that are identically hybrid for two traits