MEIOSIS
We all look different right? But how do we get our characteristics?
Get out the Meiosis and Sexual Reproduction Outreach Notes we did as homework last class period.
Use the information to create a poster that would teach someone about the processes we have just researched.
A cell with two of each kind of chromosome is called a diploid If you examined the nucleus of a cell of a pea plants, you would find that it had 14 chromosomes (7 pairs) One chromosome in each pair came from the male parent and the other from the female. A cell with two of each kind of chromosome is called a diploid or 2N
The two chromosomes of each pair in a diploid cell (2N) are called Homologous Chromosomes
Organisms produce gametes (you remember sperm or eggs) that contain one of each kind of chromosome. A cell containing one of each type of chromosome is called a haploid cell or N
Chromosome Number of Common Organisms Why Meiosis Chromosome Number of Common Organisms Organism Body Cell (2N) Gamete (N) Fruit Fly 8 4 Garden Pea 14 7 Corn 20 10 Leopard Frog 26 13 Human 46 23 Chimpanzee 48 24 Adders Fern 1260 630
Why Meiosis When cells divide by mitosis the new cells have exactly the same number and kind of chromosomes. For example, if mitosis was the only means of cell division, in fruit flies the first generation would have 8 chromosomes. 2nd Generation 16 3rd Generation 32 4th Generation 64
Why Meiosis 2n n Diploid Haploid
Crossing Over Results in new combinations of alleles on a chromosome.
U nderstanding
Which of these represents the number of chromosomes in cells before and after the process of meiosis? A.) n n B.) n 2n C.) 2n n D.) 2n 2n
Which of the following cells are the result of meiosis? A.) sperm cells B.) liver cells C.) bacteria D.) all the above E.) only B & C
Which of the following steps would not lead to genetic variation? A.) Crossing over of homologous chromosomes B.) Random alignment of the chromosomes during metaphase C.) The combination of genes from the sperm and egg D.) Alignment of chromosomes during prophase II
Crossing-over occurs during: A.) anaphase 1 B.) metaphase 1 C.) prophase 1 D.) prophase 2
Which of the chromosomes below are homologous? A. B. C. D. E.
A cell with a diploid number of 24 undergoes meiosis, how many chromosomes are in each daughter cell? A.) 6 B.) 12 C.) 24 D.) 48
The overall function of meiosis includes all of the following except _____? A.) gamete reproduction B.) growth of the cell C.) reduction of chromosome number from 2N to N D.) providing genetic variation to sexually reproducing organisms.
Which of these represents the number of chromosomes in cells before and after the process of meiosis? A.) n n B.) n 2n C.) 2n n D.) 2n 2n
Which of the following cells are the result of meiosis? A.) sperm cells B.) liver cells C.) bacteria D.) all the above E.) only B & C
Which of the following steps would not lead to genetic variation? A.) Crossing over of homologous chromosomes B.) Random alignment of the chromosomes during metaphase C.) The combination of genes from the sperm and egg D.) Alignment of chromosomes during prophase II
Crossing-over occurs during: A.) anaphase 1 B.) metaphase 1 C.) prophase 1 D.) prophase 2
Which of the chromosomes below are homologous? A. B. C. D. E.
A cell with a diploid number of 24 undergoes meiosis, how many chromosomes are in each daughter cell? A.) 6 B.) 12 C.) 24 D.) 48
The overall function of meiosis includes all of the following except _____? A.) gamete reproduction B.) growth of the cell C.) reduction of chromosome number from 2N to N D.) providing genetic variation to sexually reproducing organisms.