13.4: Terms
- Page ID
- 93196
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\(\newcommand{\avec}{\mathbf a}\) \(\newcommand{\bvec}{\mathbf b}\) \(\newcommand{\cvec}{\mathbf c}\) \(\newcommand{\dvec}{\mathbf d}\) \(\newcommand{\dtil}{\widetilde{\mathbf d}}\) \(\newcommand{\evec}{\mathbf e}\) \(\newcommand{\fvec}{\mathbf f}\) \(\newcommand{\nvec}{\mathbf n}\) \(\newcommand{\pvec}{\mathbf p}\) \(\newcommand{\qvec}{\mathbf q}\) \(\newcommand{\svec}{\mathbf s}\) \(\newcommand{\tvec}{\mathbf t}\) \(\newcommand{\uvec}{\mathbf u}\) \(\newcommand{\vvec}{\mathbf v}\) \(\newcommand{\wvec}{\mathbf w}\) \(\newcommand{\xvec}{\mathbf x}\) \(\newcommand{\yvec}{\mathbf y}\) \(\newcommand{\zvec}{\mathbf z}\) \(\newcommand{\rvec}{\mathbf r}\) \(\newcommand{\mvec}{\mathbf m}\) \(\newcommand{\zerovec}{\mathbf 0}\) \(\newcommand{\onevec}{\mathbf 1}\) \(\newcommand{\real}{\mathbb R}\) \(\newcommand{\twovec}[2]{\left[\begin{array}{r}#1 \\ #2 \end{array}\right]}\) \(\newcommand{\ctwovec}[2]{\left[\begin{array}{c}#1 \\ #2 \end{array}\right]}\) \(\newcommand{\threevec}[3]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \end{array}\right]}\) \(\newcommand{\cthreevec}[3]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \end{array}\right]}\) \(\newcommand{\fourvec}[4]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \\ #4 \end{array}\right]}\) \(\newcommand{\cfourvec}[4]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \\ #4 \end{array}\right]}\) \(\newcommand{\fivevec}[5]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \\ #4 \\ #5 \\ \end{array}\right]}\) \(\newcommand{\cfivevec}[5]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \\ #4 \\ #5 \\ \end{array}\right]}\) \(\newcommand{\mattwo}[4]{\left[\begin{array}{rr}#1 \amp #2 \\ #3 \amp #4 \\ \end{array}\right]}\) \(\newcommand{\laspan}[1]{\text{Span}\{#1\}}\) \(\newcommand{\bcal}{\cal B}\) \(\newcommand{\ccal}{\cal C}\) \(\newcommand{\scal}{\cal S}\) \(\newcommand{\wcal}{\cal W}\) \(\newcommand{\ecal}{\cal E}\) \(\newcommand{\coords}[2]{\left\{#1\right\}_{#2}}\) \(\newcommand{\gray}[1]{\color{gray}{#1}}\) \(\newcommand{\lgray}[1]{\color{lightgray}{#1}}\) \(\newcommand{\rank}{\operatorname{rank}}\) \(\newcommand{\row}{\text{Row}}\) \(\newcommand{\col}{\text{Col}}\) \(\renewcommand{\row}{\text{Row}}\) \(\newcommand{\nul}{\text{Nul}}\) \(\newcommand{\var}{\text{Var}}\) \(\newcommand{\corr}{\text{corr}}\) \(\newcommand{\len}[1]{\left|#1\right|}\) \(\newcommand{\bbar}{\overline{\bvec}}\) \(\newcommand{\bhat}{\widehat{\bvec}}\) \(\newcommand{\bperp}{\bvec^\perp}\) \(\newcommand{\xhat}{\widehat{\xvec}}\) \(\newcommand{\vhat}{\widehat{\vvec}}\) \(\newcommand{\uhat}{\widehat{\uvec}}\) \(\newcommand{\what}{\widehat{\wvec}}\) \(\newcommand{\Sighat}{\widehat{\Sigma}}\) \(\newcommand{\lt}{<}\) \(\newcommand{\gt}{>}\) \(\newcommand{\amp}{&}\) \(\definecolor{fillinmathshade}{gray}{0.9}\)Alternation of generations | Cycle of diploid, asexual, vegetative generation alternating with the haploid, sexual generation. |
Anaphase | Third phase of mitosis; the sister chromatids separate (now chromosomes) and the centromeres divide, pulling the chromosomes to opposite poles. |
Antipodal cells | Three cells sequestered at the opposite end of the mature female gametophyte from the egg and synergid cells. |
Cell cycle | Cycle which cells go through in their lifetime; consists of interphase and mitosis. |
Centromere | Constricted spot where sister chromatids attach. |
Chiasma | Point where sister chromatids of homologs lay over each other, forming an “X” shape. |
Chromosome | Structure within the nucleus of a cell that contains the genes; made up of DNA that has looped around histone proteins and then coils and folds. |
Crossing over | Exchange of arms of DNA between sister chromatids of homologous chromosomes that can take place at the point of chiasma formation. |
Cytokinesis | Occurs directly after telophase; the cell plate forms between the two daughter cells and the cell walls separate the newly formed cells. |
Diploid | Term used for zygote cells, where the cell has two sets of chromosomes; abbreviated 2n. |
DNA | Basic biochemical compound that makes up the gene. |
G1 stage of interphase | First stage of interphase; “G” stands for Gap/Growth. |
G2 stage of interphase | Third and final stage of interphase; “G” stands for Gap/Growth. |
Genetic code | Order of the four different combinations of the bases in DNA; AT, TA, GC, or CG. |
Haploid | Term used for gamete cells that typically contain one set of each of the chromosomes; abbreviated n. |
Histone protein | Protein around which the DNA surrounds. |
Homologous chromosomes (homologs) | Matching chromosomes from the two different sets; carry the genetic information that affects the same characteristic or function at the same location on the chromosome; from sperm and egg cells. |
Interphase | One of the two major parts of the cell cycle; consists of G1, S, and G2 stages. |
Kinetochore | Point of attachment of the spindle and the centromere. |
Metaphase | Second stage of mitosis; the spindle fibers grow and form attachments to the pairs of sister chromatids at the centromeres. |
Metaphase plate | Equatorial plate formed along the midline of the cell between the poles. |
Nucleosome | Made up of eight histone proteins and wrapped by a segment of DNA. |
Ploidy | Number of sets of homologous chromosomes in a cell. |
Polar nuclei | Two haploid nuclei contained within one cell membrane in the mature female gametophyte. One sperm cell will unite with these two polar nuclei to establish the triploid endosperm tissue. |
Prophase | First stage of mitosis; chromatin begins to coil and condense to form chromosomes. |
Purine | Consists of the base pairs Adenine and Guanine and contains two rings of carbon atoms. |
Pyrimidine | Consists of the base pairs Cytosine and Thymine and contains one ring of carbon atoms. |
Ribose-phosphate backbone | Chain of alternating ribose and phosphate that make up the sides of the DNA structure. |
S stage of interphase | Second stage of interphase where the chromosomes replicate (DNA replicated). |
Sister chromatids | Two chromosomes that are exact copies and are created during the S stage of interphase. |
Somatic cells | Cells of flowering plants, other than the reproductive cells; always 2n. |
Spindle apparatus | Microtubules associated with movement of the chromosomes during division. |
Sporangia | Structures in the androecium and gynoecium where meiosis takes place and the gametophyte generation develops. |
Spore | Haploid single cell produced by meiosis in the sporangium of a diploid sporophyte. |
Telophase | Fourth and final stage of mitosis; the nuclear membrane forms around the chromosomes in each of the daughter cells. |
Tetrads | Groupings of four sister chromatids. |
Triploid | Term used for endosperm that has three sets of chromosomes; abbreviated 3n. |