Anthropology Vocab 1- Genetics

Front 1

Nucleus

Back 1

The control center of the cell. It contains all genetic material.

Front 2

Chromatin

Back 2

Long strands of intertwined DNA found in the nucleus when the cell is resting(not dividing). When the cell divides the chromatin strands shorten, thicken and become the chromatids which become chromosomes.

Front 3

Chromatid

Back 3

Each strand of chromosome during cell division, it is formed when the chromatin thickens.

Front 4

Chromosome

Back 4

Dark-staining, rod shaped bodies containing the DNA. Chromosomes are only found in the nucleus of the cell.

Front 5

Centromere

Back 5

The point of attachment of the two strands of a double-stranded chromosome.

Front 6

Centriole

Back 6

A small, granular structure in the cytoplasm, which divides during cell division. The daughter centrioles migrate to opposite sides of the cell, sending out spindle fibers that pull the chromatids apart at the centromere.

Front 7

Spindle Fibers

Back 7

The strands that originate from the centioles and attach to the centromeres, they pull the chromosomes apart into separate chromatids.

Front 8

Cytokinesis

Back 8

The physical splitting of a cell into 2 halves.

Front 9

Diploid

Back 9

The full number of chromosomes(46 in humans)

Front 10

Haploid

Back 10

Half the complement of chromosomes (23 in humans). Gametes are haploid cells.

Front 11

Somatic cells

Back 11

All the cells in the body except those involved with primary reproduction.

Front 12

Sex cells

Back 12

The reproductive cells (egg and sperm) that produce gametes

Front 13

Prophase

Back 13

The cell prepares for division. The chromatin twist into chromatids and chromosomes are formed. The nuclear membrane is dissolved and the centrioles have migrated to opposite poles of the mother cell.

Front 14

Metaphase

Back 14

The chromosomes line up along the equator of the cell. The spindle fibers extend from the centioles and attach at the centromeres.

Front 15

Anaphase

Back 15

The spindle fibers pull the chromosomes apart, leading the identical sets of chromatids to opposite sides of the cell. Each of the chromatids will now be considered independent chromosomes for each for each of the new daughter cells.

Front 16

Telophase

Back 16

Cytokinesis (the division of cytoplasm)occurs. The mother cell begins to split, the nuclear membranes reform and the chromatids begin to elongate into chromatin. The cell splits into two identical daughter cells (each cell is a diploid). Once this phase is complete, the new cells enter Interphase and replicate DNA in preparation for the next cell division.

Front 17

Homologous

Back 17

Two chromosomes carrying similar, but not identical, genetic information

Front 18

Synapsis

Back 18

The pairing of homologous chromosomes to each other.

Front 19

Tetrad

Back 19

The unit formed by the synapse of homologous chromosomes.

Front 20

Crossing over

Back 20

The recombination of chromosomal material by the breaking off and reforming of the arms of homologous chromosomes.

Front 21

Reduction Division

Back 21

The first meiotic division, which reduces the number of chromosomes in the original cell by splitting the tetrads.

Front 22

Equatorial division

Back 22

The second division, which splits the tetrads into chromatids, creating the haploid number for all four resulting cells.

Front 23

Polar Body

Back 23

A leftover cell in Oogenesis resulting from uneven cell division (cytokinesis).

Front 24

Nondisjunction

Back 24

A mistake in meiosis when the tetrads are not separated, resultin in an unequal number of chromosomes in the cells.

Front 25

Mutation

Back 25

A misreading of the DNA during replication. Mutations can be of only one base (point mutation) or can be of a large section left out, added on or jumbled. Mutation in mitosis is a somatic mutation and only affects the cells produced by an affected cell.

Front 26

Point mutation

Back 26

A change that occurs in a single base of a DNA sequence and may or may not change the amino acid sequence in the protein that is being produced.

Front 27

Prophase I

Back 27

The cell prepares for division. The chromatin twist into chromatids, the nuclear membrane begins to dissolve. Chromosomes are formed, the nuclear membrane is dissolved and the centrioles have migrated to opposite poles of the mother cell. The homologous chromosomes synapse to form tetrad bundles. Crossing over occurs at this time.

Front 28

Metaphase I

Back 28

The tetrads line up along the equator of the cell. The spindle fibers attach at the centromeres.

Front 29

Anaphase I

Back 29

Reduction phase. The spindle fibers pull the tetrads apart, leading the homologous chromosomes to opposite sides of the cell.

Front 30

Telophase I

Back 30

Cytokinesis (splitting of the cytoplasm) occurs. The nuclear membranes reform and the cell divides in two. Each cell is now haploid and carries different, but similar, genetic information.

Front 31

Prophase II

Back 31

The cell prepares for division. The centrioles divide and the nuclear membrane begins to dissolve. Centrioles migrate to opposite poles, the spindle formation begins and the nuclear membrane is dissolved.

Front 32

Metaphase II

Back 32

The chromosomes line up on the equators of both cells and the spindle fibers attach to centromeres.

Front 33

Anaphase II

Back 33

The chromosomes are split into chromatids and each is carried to opposite sides of the cell.

Front 34

Telophase II

Back 34

Cytokinesis occurs. The nuclear membranes reform and both cells begin to split. The four cells produced are haploid.