Biology-Ch.38 Response

Biology-Ch.38 Response - make 4N megaspores usually only 1...

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
Ch.38 Response Chapter 38: Describe alternation of generations using proper terminology. 1. Sporophyte (2N) makes N spores by meiosis. 2. Gametophyte (N) arises by mitosis of spores (multicellular) and produces gametes (sperm and egg). 3. Stamen-filament and anther-produces pollen (male gametophyte) 4. Carpel-ovary, stigma, style, and ovary sacs in ovary-produces egg (female gametophyte) Pollen Grain: in microsporangia of anther, there are many 2N microsporocytes which undergo meiosis to make 4 microspores. Microspores divide by mitosis into 2 cells: generative (sperm producing) and tube (makes pollen tube) cells. Embryo Sac: ovules containin megasporangium from the ovary. Megasporocytes undergo meiosis to
Background image of page 1
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: make 4N megaspores, usually only 1 megaspore survives and its nucleus divides 3 times to make 1 big cell with 8 nuclei. The cell is then partitioned into 1 egg cell and 2 synergids on 1 side and 3 antipodal cells on the other, and 2 polar nuclei in the middle. 5. Pollination-pollen lands on appropriate stigma and germinates. Tube cell forms pollen tube, generative cell forms 2 sperm by mitosis. 1 sperm (N) fertilizes egg (N) to make a 2N zygote (the Sporophyte). Other sperm fertilizes polar bodies to make 3N endosperm....
View Full Document

This homework help was uploaded on 04/07/2008 for the course BIOL 152 taught by Professor Schnurr/vawter during the Spring '08 term at Wells.

Ask a homework question - tutors are online