1 1 Asexual Reproduction Mitosis DSQ: Mitosis is the process in which the nucleus divides to form two new nuclei. How does mitosis differ in plants and animals? Mrs. Camp 7 th Grade Life Science
DSQ: Mitosis is the process in which the nucleus divides to form two new nuclei. How does mitosis differ in plants and animals?
8 8 Asexual Reproduction Mitosis DSQ: Mitosis is the process in which the nucleus divides to form two new nuclei. How does mitosis differ in plants and animals? ANALYZE (break apart, study the pieces) There is a question within a question in this DSQ. Can you identify the question within the DSQ?
How do little elephants grow up to be BIG elephants?
increases the number of cells and causes many- celled ORGANISMS to grow.
series of events that takes place from one cell division to the next. › Cells have periods of formation, growth and development and death called › Life cycles › Interphase- most of the life of any eukaryotic cell or cell with a nucleus, is spent in a period of growth and development. During interphase, a cell duplicates its chromosomes and prepares for cell division. After interphase, the nucleus divides and then cytoplasm separates to form two new cells.
process in which the nucleus divides to form two identical nuclei. Chromosomes- structure that contains hereditary material. Prophase › Nucleolus and nuclear membrane disintegrate. › Centrioles move to opposite ends of the cell. › Spindle fibers begin to stretch across the cell.
pairs of chromatids line up across the cell. 4. Anaphase a. Each centromere divides b. Each pair of separates line up across the center of the cell. 5. Telophase- spindle fibers disappear and new nucleus forms.
for most cells, the cytoplasm Separates after the nucleus divides. In animal cells, the cell membrane pinches in the middle and the cytoplasm divides. In plant cells, a cell plate forms.
Each cell in your body, except sec cells, has a nucleus with 46 chromosomes. Allows growth and replaces worn out or damaged cells.
a new organism is produced from one parent organism. An organism with no nucleus divides into two identical organisms by fission. Budding- a small, exact copy of the adult grows from the body of the parent. In regeneration, a whole new organism grows from each piece of the parent.
The process of asexual reproduction begins after a sperm fertilizes an egg.
Skin cancer - the abnormal growth of skin cells - most often develops on skin exposed to the sun. Cell that reproduce by asexual reproduction reproduce constantly.
Animated Mitosis Cycle Interphase Prophase Metaphase Anaphase Telophase & Cytokinesis
Chromosomes are copied (# doubles) Chromosomes appear as threadlike coils ( chromatin ) at the start, but each chromosome and its copy( sister chromosome) change to sister chromatids at end of this phase CELL MEMBRANE Nucleus Cytoplasm
Animal Cell Plant Cell Photographs from:
Mitosis begins (cell begins to divide) Centrioles (or poles) appear and begin to move to opposite end of the cell. Spindle fibers form between the poles. Centrioles Sister chromatids Spindle fibers
Animal Cell Plant Cell Photographs from: Spindle fibers Centrioles
Chromatids (or pairs of chromosomes) attach to the spindle fibers. Centrioles Spindle fibers
Animal Cell Plant Cell Photographs from:
Chromatids (or pairs of chromosomes) separate and begin to move to opposite ends of the cell. Centrioles Spindle fibers
Animal Cell Plant Cell Photographs from:
Two new nuclei form. Chromosomes appear as chromatin (threads rather than rods). Mitosis ends. Nuclei Chromatin
Animal Cell Plant Cell Photographs from:
Cell membrane moves inward to create two daughter cells – each with its own nucleus with identical chromosomes.
Animal Mitosis -- Review Interphase Prophase Metaphase Anaphase Telophase Interphase
Plant Mitosis -- Review Interphase Prophase Metaphase Anaphase Telophase Interphase
I I nterphase P P rophase M M etaphase A A naphase T T elophase C C ytokinesis IPMATC I Play M ovies At T he Cinema
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36 - Cell Division 36
A. Sexual reproduction- two sex cells, usually an egg and a sperm, come together. › Fertilization- the joining of an egg and a sperm, generally from two different organisms of the same species. Sperms are formed in the male reproductive organs. Eggs are formed in the female reproductive organs. A cell that forms from fertilization is a zygote
Following fertilization, cell division begins and a new organism develops. Human body cells are diploid, because they have 23 pairs of similar chromosomes. Human sex cells are haploid, because they have 23 single chromosomes.
a process that produces haploid sex cells and ensures that offspring have the same diploid as its parent. › In meiosis I, the nucleus divides and produces two new cells with one duplicated chromosome each › In meiosis II, the nuclei divides and the chromatids separate, producing FOUR cells with half the number of chromosomes of the original nucleus.
A. DNA-A chemical that contains information that an organism needs to grow and function 1. Watson and Crick made an accurate model of DNA in 1953
2. The structure of DNA is similar to a twisted ladder. A. the side of the ladder are made up of sugar- phosphate molecules. B. The rungs of the ladder are made up of nitrogen bases. 3.Before a cell divides, its DNA duplicates itself by unwinding and separating its sides, then each side becomes a pattern on which a new side forms.
sections of DNA on a chromosome 1. Contain instructions for making specific proteins 2. RNA carries the codes for making proteins from the nucleus to the ribosome’s in the cytoplasm.
a.Messenger RNA carries the code that directs the order in which the amino acids bond. b. Ribosomal RNA makes up ribosome’s, where proteins are built. c. Transfer RNA brings amino acids to the ribosome’s to build the protein.
3. Cells use only the genes that direct the making of proteins needed by that cell.
Any permanent change in the DNA sequence of a cell’s gene or chromosome 1. Can be caused by outside factors like X rays, sunlight and some chemicals. 2. A change in a gene or chromosome can change the traits of an organism.