Interphase & Cell Division

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1 1 Interphase & Cell Division

2 2 G1 = cell grows and carries out its normal job. S phase = DNA is copied (replicated/duplicated) G2 = Cell prepares for division

3 3 During mitosis, the nuclear membrane breaks down and the copied chromosomes are separated to either side of the cell. (this is mitosis) Then, the cell divides. (This is cytokinesis)

4 4 The cytoplasm of the cell divides, cutting the cell in half. In animals, the cell pinches in half. In plants, the cell builds a new cell wall in the middle of the cell. The new cell wall is called a cell plate.

5 5 A = Early Prophase B = Telophase C = Metaphase D = Interphase E = Anaphase F = Late Prophase

6 6 Phase Prophase Description DNA condenses to form chromosomes. Nuclear envelope breaks down. Metaphase Anaphase Copied chromosomes line up at the center (equator) of the cell. Copied chromosomes (sister chromatids) split apart and begin moving to the poles of the cell. Telophase The exact opposite of prophase. DNA unwinds and the new nuclear envelopes reform.

7 7 Mitosis is for growth and repair. Meiosis is for production of gametes

8 8 Haploid = a cell with half the normal number of chromosomes. These cells are usually gametes. Diploid = a cell with a full set of chromosomes. These cells are usually somatic cells.

9 9 Asexual & Sexual Similarities Both are types of reproduction Both involve the production of new cells Differences Asexual produced identical cells. Sexual produces different cells. Asexual is an advantage when the environment is stable. Sexual is an advantage when the environment is changing.

10 10 Mitosis is asexual because the daughter cells are identical to the parent cell.

11 11 Meiosis is sexual because the daughter cells are different from the parent cells.

12 12 Body cell or sex cells? # of divisions? # of stages (total)? # of cells produced? # of chromosome s in cells produced? Mitosis Body cells 1 4 (PMAT) 2 Same number (cells are diploid) Meiosis Sex cells 2 8 (PMAT, PMAT) 4 Half (cells are haploid)

13 13 A gamete = a sex cell (sperm or egg) Gametes are haploid. Sperm are produced via spermatogenesis. Eggs are produced via oogenesis.

14 14 Crossing over is the exchange of DNA between homologous chromosomes. It occurs during Prophase 1 of meiosis. You have a picture of crossing over on your study guide.

15 15 DNA is in the nucleus in eukaryotes (in the cytoplasm in prokaryotes). RNA can be in both the nucleus and the cytoplasm.

16 16 3 parts of a nucleotide = Phosphate, sugar and a nitrogen base. The drawing is already labeled.

17 17 DNA nitrogen bases: Adenine Thymine Guanine Cytosine

18 18 Chargaff s rule: A with T and C with G

19 19 Given: ATGCCGT Asked: TACGGCA

20 20 DNA is a double helix ( twisted ladder.)

21 Watson and Crick 21

22 22 During DNA replication, a copy of the DNA is made. Each new copy is made of one original strand and one new strand. This is called semi-conservative replication.

23 22 continued

24 23 1.) The DNA separates (due to enzymes) 2.) The two strands are copied.

25 SKIP this question 24

26 25 Adenine -- Uracil Guanine -- Cytosine

27 26 ATGGTCA DNA strand - given UACCAGU complementary mrna strand

28 27 Messenger RNA = C Transfer RNA = A Ribosomal RNA = B

29 28 During transcription, mrna is made from a section of DNA. It happens in the nucleus WHY???

30 29 During translation, a protein is made by the ribosome. The ribosome reads the mrna message and makes the protein. This happens at a ribosome (either in the cytoplasm or attached to the E.R.).

31 codon 30

32 31 20 different amino acids are possible

33 32 Proteins: Build muscles and bones Provide ways for cells to communicate with other cells. Serve as enzymes Function as antibodies Serve as channels for substances to enter the cell Facilitated diffusion (a type of passive transport) Serve as pumps to move things in and out of the cell (Active transport)

34 33 Missense = one codon is changed, resulting in a different amino acid being produced. (GUA GGA) Nonsense = a change in a codon causes a stop codon to be produced. (CGA UGA) Insertion = an extra base is added to the DNA sequence. Deletion = a base is deleted from the DNA sequence. Duplication = an copy of a sequence of DNA is added to the same DNA strand.

35 34 Point mutations only affect one codon. Frameshift mutation affect all codons in the DNA strand after the mutation. Remember: THE FAT CAT WAS MAD.

36 35 Mendel was the first person to scientifically study inheritance. He is considered the Father of Genetics.

37 36 He studied pea plants. Why: 1.) They reproduce sexually by self-pollination. This allowed Mendel to control what traits he was testing for. 2.) They were easy to grow, easy to maintain and were easy to obtain.

38 Homozygous 37

39 Heterozygous 38

40 Dominant 39

41 Recessive 40

42 41 The genetic make up of an organism You cannot see this, but you can infer it.

43 42 The physical trait coded for by the alleles. You can see this.

44 43 Your Parents = P generation You = F1 generation Your kids = F2 generation

45 44 B= black; b= brown a.) BB = homozygous black b.) bb = homozygous brown c.) Bb = heterozygous black