Genetics

Question 1

Meiosis

Answer 1

Cell division that produces reproductive cells in sexually reproducing organisms

Question 2

Prophase I

Answer 2

DNA coils & condenses into chromosomes which contain 2 sister chromatids

Nuclear membrane break down

Homologous chromosomes pair up together and form a tetrad (4 sister chromosomes side to side)

Homologous chromosomes can exchange sections of DNA, which we call Crossing Over.

Question 3

Crossing Over

Answer 3

This is the process where the two homologous pairs of chromosomes mix their genes together to create a unique tetrad

Question 4

Zygote

Answer 4

The unified cell between a sperm and egg cell after fertilization.

Question 5

Metaphase I

Answer 5

Tetrads (paired homologous chromosomes) line up at the middle of the cell

They line up randomly which increases the genetic variation. This is called independent assortment.

Question 6

Anaphase I

Answer 6

Homologous pairs are separated and pulled to opposite ends of the cells.

The centromere are NOT pulled apart

Question 7

Telophase I and Cytokinesis

Answer 7

The nuclear membrane re-forms around chromosomes, which uncoil

Chromosomes are still composed of chromatids (still in an x-shape) but only half of the DNA is present in each daughter cell

Each cell has become a haploid and is not identical

The cleavage furrow forms and cytokinesis follows

Question 8

Prophase II

Answer 8

No interphase occurs

Nuclear membrane disappears, DNA condenses

Question 9

Metaphase II

Answer 9

spindle fibers pull chromosomes so they are lined up in the middle of the cell in single file.

Question 10

Anaphase II

Answer 10

Centromeres divide

Chromatids come apart to migrate separately to each pole

Question 11

Telophase II & cytokinesis

Answer 11

Daughter chromatids unwind into chromatin

Nuclear membrane reforms

Cytoplasm splits in cytokinesis

Four haploid daughter cells are formed

Question 12

Deletion

Answer 12

a piece of a chromosome is deleted

ex: Cri du Chat

Question 13

Duplication

Answer 13

a section of a chromosome appears two or more times in a row

ex: Charcot-Marie-Tooth disease

Question 14

Inversion

Answer 14

a section of a chromosome is inverted

ex: FG Syndrome

Question 15

Translocation

Answer 15

a segment of one chromosome becomes attached to a different chromosome

ex: Chronic Myelogenous

Question 16

Down Syndrome

Answer 16

extra chromosome on 21st pair (trisomy)

• short height
• deformed face
• mental disabilities

Question 17

Patau’s Syndrome

Answer 17

Extra chromosome on the 13th pair

• physical abnormalities
• Extra toes and fingers
• Cyclopia

Question 18

Edward’s syndrome

Answer 18

Extra chromosome on the 18th pair

• Heart defects & kidney and CNS
• Malformed ears
• Small math

Question 19

Klinefelter Syndrome

Answer 19

Two x chromosomes and on y chromosomes

• biological male at birth

Question 20

XXX Female

Answer 20

Three x chromsomes

Question 21

Turner’s syndrome

Answer 21

one x chromosome

• short height

Question 22

Synapsis

Answer 22

Connection of homologous chromosomes to form a tetrad

Question 23

Centromere

Answer 23

Area where the chromatids of a chromosome are attached

Question 24

Chromatin

Answer 24

a mixture of DNA and proteins that form the chromosomes found in the cells of humans and other higher organisms

Question 25

Chromosomes

Answer 25

threadlike structures made of DNA molecules that contain the genes

Question 26

Sister chromatid

Answer 26

Replicated forms of a chromosome joined together by the centromere and eventually separated during mitosis or meiosis II.

Question 27

Supercoil

Answer 27

A coil of coils; a circular molecule of DNA can coil upon itself to form a supercoil.

Question 28

Homologous chromosomes

Answer 28

Chromosomes that have the same sequence of genes and the same structure

Question 29

Karyotype

Answer 29

A display of the chromosome pairs of a cell arranged by size and shape.

Question 30

Mitosis

Answer 30

cell division for growth and repair of cells

Question 31

Interphase

Answer 31

Cell grows, performs its normal functions, and prepares for division; consists of G1, S, and G2 phases

G1 phase: When the cell grows

S phase: When DNA replicates

G2 phase: Synthesis occurs again

Question 32

Prophase

Answer 32

Chromosomes become visable, nuclear membrane dissolves, spindle forms

Question 33

Metaphase

Answer 33

Chromosomes line up in the middle of the cell

Question 34

Anaphase

Answer 34

Phase of mitosis in which the chromosomes separate and move to opposite ends of the cell

Question 35

Telophase

Answer 35

the final phase of cell division, between anaphase and interphase, in which the chromatids or chromosomes move to opposite ends of the cell and two nuclei are formed.

Question 36

Cytokinesis

Answer 36

division of the cytoplasm

Question 37

Diploid

Answer 37

2 sets of chromosomes

Question 38

Haploid

Answer 38

having a single set of unpaired chromosomes

Question 39

Independent assortment

Answer 39

Independent segregation of genes during the formation of gametes

Question 40

Non disjunction

Answer 40

Error in meiosis in which homologous chromosomes fail to separate.

Question 41

Gamete

Answer 41

sex cell

Question 42

Tetrad

Answer 42

structure containing 4 chromatids that forms during meiosis

Question 43

Cancer

Answer 43

any malignant growth or tumor caused by abnormal and uncontrolled cell division

Question 44

Malignant

Answer 44

Cancerous

Question 45

Benign

Answer 45

mild, not cancerous