Therefore the purpose of meiosis is to produce gametes; the sperm and eggs. 3. In what ways is meiosis different from mitosis? Be thorough. Comparison chart | Meiosis | Mitosis | Definition: | A type of cellular reproduction in which the number of chromosomes are reduced by half through the separation of homologous chromosomes in a diploid cell.
January 11, 2014 Pgs: 250-257 AP Biology Meiosis and Sexual reproduction 1. Differentiate between haploid and diploid cells. Give one example of each cell. The difference between a haploid and a diploid cell is that a diploid is a cell that has two sets of chromosomes. On the other hand, a haploid cell contains only one set of chromosomes.
Or each chromosome of a pair can be individually picked. 16. Explain two ways in which children can have different chromosomes (gene variation) than their mother or father. Random separation of chromosomes (law of segregation) when forming sperm/ova during anaphase I, crossing over of some genes to the homologous chromosomes during prophase I, and mutation during S
Since the chromosome pairs carry different genes, the daughter cells (sex cells) produced by meiosis are almost always genetically different. See Biozone. 3.5 Explain the role of gamete formation and sexual reproduction in variability of offspring Genetic variability of offspring occurs for a number of reasons: 1. During sexual reproduction, two sex cells join together in a process called fertilization. Which sex cells join together during fertilization is a random process.
GENETICS-1 1) Complex organisms produce sex cells that unite during fertilization, forming a single cell known as a) an embryo c) a gonad b) a gamete d) a zygote 2) A cell with a diploid chromosome number of 12 divided two times, producing four cells with six chromosomes each. The process that produced these four cells was most likely a) internal fertilization b) external fertilization c) mitotic cell division d) meiotic cell division 3) Which diagram represents a pair of homologous chromosomes? 4) In minks, the gene for brown fur (B) is dominant over the gene for silver fur (b). Which set of genotypes represents a cross that could produce offspring with silver fur from parents that both have brown fur? a) Bb x Bb c) BB x BB b) BB x bb d) Bb x bb 5) When a certain pure strain of fruit fly is cultured at a temperature of 16˚C, all of the flies will develop straight wings.
Mitosis is the step during which the cell’s nucleus divides into two new nuclei. During mitosis, one copy of the DNA is distributed into each of the two daughter cells. Scientists divide mitosis into four parts (phases): prophase, metaphase, anaphase, and telophase. During prophase, the thread-like chromatin in the nucleus condenses to form double-rod structures called chromosomes. During metaphase, the chromosomes line up across the center of the cell.
Distinguish between a identical and non-identical twins. Do all identical twins develop the same way? Fraternal twins, or non-identical twins, also called dizygotic twins, can happen when multiple eggs are released at one time or if there’s more than one ovulation and both eggs are fertilized by separate sperm. Identical twins, or monozygotic twins, happen when there’s only one egg, and it’s fertilized by only one sperm, but it splits into two. Identical
One of the causes that brought about the differences in alleles is sexual reproduction during meiosis. There are two main events during meiosis, crossing over of chromatids and independent segregation of chromosomes. During meiosis I, homologous pairs of chromosomes come together and pair up. The chromatids twist around each other and bits of chromatids swap over, the crossing over of chromatids in meiosis I means that each of the four daughter cells formed from meiosis II contain chromatids with a different set of alleles, which increases genetic variation. Meanwhile during the independent segregation of chromosomes, half of your chromosomes come from your mum (called maternal chromosomes) and half from your dad (called paternal chromosomes).
• Environmental influences are crucial for almost every complex trait, with each child as well as each culture experiencing different environments. Chromosomal and Genetic Abnormalities: • Every normal human cell, except for sperm and egg cells, has 23 pairs of chromosomes for a total of 46 chromosomes. Sperm and egg cells have only one of each pair of chromosomes for a total of 23. Each chromosome contains hundreds to thousands of genes. • The sex chromosomes are one of the 23 pairs of chromosomes.
The reason for the mutations is that the DNA inside a natural embryo is programmed to set off signals to activate certain sets of genes. Later, when the embryonic cells differentiate, the programs change. In cloning, the natural embryo has a completely different program then the transferred nucleus. This causes certain genes to be activated in a completely different order then the original. Lucky for Dolly and very few other clones, their genetic programs were very similar to that of the original.