A pollen grain of corn with nuclei labeled M, N, O fertilized an embryo sac with nuclei labeled R, S, T, U, V, W, X, & Y, as shown below: (10 pts) 0 N M tube nucleus antipodals R U X egg nucleus S V W T Y synergids ** M is tube nucleus; RST are antipodals; X is egg nucleus; WY are synergids a. Which of the 5 combinations could be found in the embryo? (1) MNO (2) NOX (3) UVN (4) MW (5) OX. What is the basis of your choice? b. Which of the above combinations could be found in the endosperm layer of the seed? Why? C. Which of the nuclei, if any, in the pollen grain would contain genetically identical sets of chromosomes? Give basis of your answer. d. Which of the nuclei in the embryo sac would be chromosomally and genetically identical? Why? e. Which of the nuclei in these two gametophytes will have no descendants in the mature seed?

Arrange the following events of meiosis in the correct sequence * crossing over O synapsis terminalisation of chiasmata disappearance of nucleolus

What structure is indicated by the letter A in the image below? A O sperm O spore egg

Cells that are ________ possess a single set of chromosomes   diploid   haploid   somatic   zygotes

mitosis nuclei resides in the nucleus karyotype autosomes haploid In dividing parent cell; in the parent cell. Male and female gametes at fertilization forms a homologs Microscopic observations showed that during fertilization, the unite, providing evidence that genetic material resides in the cell membrane Brightly staining, threadlike bodies within the nucleus were termed of these bodies could be traced through cell division. chromosomes diploid A image can reveal abnormalities in meiosis of eggs and sperm ; the movements gametes contain a single set of chromosomes. The fusion of zygote. the number of chromosomes in daughter cells remains the same as in the the number of chromosomes in daughter cells is half that of Two chromosomes that match in size, shape, and banding when isolated and stained are is an image of an individual's chromosomes arranged in homologous pairs. This chromosome number and structure nondisjunction

Which of the following cany the same genetic infor mation ? A - all autosome D- homologous chromosomes B - sister chromatids E-X and Y chro monsomes C-all haploid cells

Fertilized egg What structure tells you what stage this is? Blastocoel O Visible nucleus O Archenteron Blastopore O Fertilization envelope

Chromosomes per cell Chromosomes status DNA (molecules) per cell DNA picograms per cell Ploidy G1 ∞∞o 6 6 20 2n S G2 Prophase and prometaphase OO Metaphase Anaphase Telophase and cytokinesis

With the whitefish blastual cell during interphase, prophase, metaphase, anaphase, telophase and cytokinesis when is cell furrow, chromosomes, duplicated chromosomes,mmitotic spindle and nucles present and visable?

A cytology student believes he has identified an individual with monoploidy. The instructor views the dividing cells under the microscope and correctly dismisses the claim. Why was the claim dismissed? What types of cells were being viewed?