Botany - Cells Divide/ Genetics

Front 1

Cells divide for

Back 1

and replace worn out cells, repair injuries

Front 2

To produce gametes

Back 2

usually nuclei divide prior to each cell division so that each new cell will have a nucleus, just like the parent’s nucleus

Front 3

Cells not involved in sex (most cells) are called

Back 3

somatic cells; typically have pairs of chromosomes or diploid

Front 4

gene

Back 4

is part of a DNA molecule, specifying one complete protein molecule. This may determine an obvious or not so obvious trait, or may combine with other genes to do so.

Front 5

Strands

Back 5

are attached at a centromere; Chromosomes length and centromere placement helps geneticists identify different chromosomes

Front 6

Gametes

Back 6

or sex cells are haploids (1n) So are the cells of the gamete that produced them

Front 7

Plant’s life cycles alternate between a haploid gamete producing gametophytes and a diploid spore producing sporophytes

Back 7

alternation of generations

Front 8

Synamy

Back 8

is the union of 2 gametes to form 1 diploid cell called a zygote.

Front 9

Polyploidy

Back 9

plant has more than two sets of chromosomes.

Front 10

Autoploidy

Back 10

duplicated chromosome pairs don’t separate during nuclear division; may result in viable tetraploid

Front 11

Interphase

Back 11

term is divided into G1, S, and G2. In meristems, about 90% of the cells at any one time are in interphase. This phase takes longer than more DNA nucleus has to replicate or if it is cool

Front 12

Chromosomes

Back 12

look like tangled threads; can’t see individual chromosomes so matter is called chromatin

Front 13

G1

Back 13

(stands for gap one) Cells store chemical energy and proteins needed for DNA synthesis
Nucleoli used ribosomes sythesis; cells that leave the cycle to differentiate are arrested in G1

Front 14

S

Back 14

(stands for synthesis) DNA is replicated (synthesized) except for centromere, which replicates just for division just before division.

Front 15

G2

Back 15

– (gap 2) Cells store energy for chromosomes movement and proteins such as those used to make microtubules (which will comprise of the spindle fibers)

Front 16

M

Back 16

Nuclear division: mitosis or meiosis) The nucleus divides, with the separation of chromosomes replicates

Front 17

Mitosis

Back 17

is the formation of two genetically identical nuclei, also identical to their parent.

Front 18

Meiosis

Back 18

or reduction division) is the formation of 4 daughter cells, each with one unreplicated chromosome of each typel this is how gametophytes are formed

Front 19

D

Back 19

division of the cell; Cytokinesis Division of the cytoplasm by cell wall formation. Often begins in the last phase of M.

Front 20

meristems

Back 20

mitosis occurs in areas of growth

Front 21

Prophase

Back 21

chromosomes become obvious as they shorten and thicken (to allow separation in the cell) but it is still hard to tell that they are made of 2 chromatids (the original chromosomes and the copy made in interphase; attached at their sister centromeres

Front 22

Metaphase

Back 22

nucleoplasm elongates; spindle fibers, bundles of microtubules, extend from the chromosomes to opposite poles of the cell.

Front 23

Anaphase

Back 23

sister centromeres of all the chromosomes separate and duplicate chromosomes move to opposite poles of the cell. Takes minutes. As soon as they separate, sister chromatids are considered chromosomes

Front 24

Telophase

Back 24

Chromosomes uncoil and group together at the poles. Nucleolus and nuclear membrane form, conforming closely to the ends of the chromosomes

Front 25

Cytokinesis

Back 25

usually follows late anaphase or telophase and may be considered a part of mitosis
Spindle fibers are surrounded by amorphous material at the equator

Front 26

Prophase I

Back 26

Chromatin contracts; homologous chromosomes pair

Front 27

Synapsis

chiasma

Back 27

Homologs coil about each other

tetrads,While paired, 2 of the 4 chromatids, 1 from each homolog, lie in a crisscross formation

Front 28

Metaphase I

Back 28

Centromeres of paired homologous chromosomes move to the cell’s equator

Front 29

Anaphase I

Back 29

Centromeres separate and chromosomes move to opposite poles

Front 30

Telophase I

Back 30

Chromatids group at opposite poles

Front 31

Prophase II

Back 31

Chromosomes reform, each with 2 composite chromatids

Front 32

Metaphase II

Back 32

Centromeres line up on equatorial plate

Front 33

Anaphase II

Back 33

Centromeres split and separate Single chromatids move to opposite poles

Front 34

Telophase II

Back 34

New nuclei form, each containing 1 chromatid of each type

Front 35

Genetics

Back 35

is the study of inheritance, founded by Austrian monk named Gregor Mendel

Front 36

Chromosomes

Back 36

are made of DNA and associated substances; DNA codes instructions for life processes

Front 37

nucleotide

Back 37

a 5 carbon sugar + a phosphate group (P04) + a nitrogen containing bas

Front 38

A & G

C and T

Back 38

purines

pyrimidines

Front 39

The sequence of nucleotides in DNA is grouped

Back 39

genes

Front 40

hypothesized the structure of DNA

Back 40

Maurice Wilkins, James Watson, and Francis Crick

Front 41

RNA

Back 41

decodes the DNA by the processes of transcription and translation, thereby directing protein synthesis

Front 42

3 kinds of RNA

Back 42

Messenger RNA (mRNA) Transfer RNA (tRNA) Ribosomal RNA (rRNA)

Front 43

codon

Back 43

Sequence of (3) nucleotides on a strand of mRNA

Front 44

Genotype

Back 44

the entire genetic makeup of an organism –its DNA

Front 45

cytoplasmic or extra nuclear inheritance

Back 45

few characteristics are passed along the female gamete’s cytoplasm

Front 46

Phenotype

Back 46

expression of the genotype (outward appearance)

Front 47

Alleles

Back 47

are alternative expressions of a gene

Front 48

homozygous

Back 48

protein molecule is the same on both chromosomes (for that trait)

Front 49

heterozygous

Back 49

genotype for a given protein molecule is different on both chromosomes

Front 50

incomplete dominance

Back 50

neither allele is dominant, result is blending (mixed phenotype)