Biology Unit 9 Questions
What does Meiosis I and Meiosis II each separate?
1: homologous pairs of chromosomes 2: chromatids
What happens during crossing over?
Chromosomes exchange genetic information, independent assortment is the random line up of chromosomes during metaphase.
Compare and contrast diploid and haploid cells and give an example.
Diploid cells contain both members of a homologous pair (2n). [somatic cells] Haploid cells contain only one member of a homologous pair (1n). [gametes]
Explain genetic recombination and how it relates to evolution.
Genetic recombination results in variation between parents and offspring therefore increasing the chance of offspring survival and ultimately species survival. In a population, this sort of genetic variation is important to allow organisms to evolve in response to a changing environment. These DNA rearrangements are caused by a class of mechanisms called genetic recombination.
What is the chromosome number for human somatic cells?
In a human somatic cell, there are a total of 46 total chromosomes (44 autosomes + 2 sex chromosomes). In a human somatic cell there are a total of 23 pairs of chromosomes (22 pairs of autosomes + 1 pair of sex chromosomes).
What is the chromosome number for human sex cells?
In human gametes, there are 23 total chromosomes (22 autosomes + 1 sex chromosome). Female eggs carry an X, male sperm carry an X or a Y.
Identify all the parts of meiosis in order.
Meiosis I: Prophase I, Metaphase I, Anaphase I, Telophase I Meiosis II: Prophase II, Metaphase II, Anaphase II, Telophase II
Compare and contrast mitosis and meiosis.
Mitosis: - Produces genetically identical cells - Results in diploid cells - Takes place throughout an organism's lifetime - Involved in asexual reproduction Meiosis: - Produces genetically unique cells - Results in haploid cells - Takes place only at certain times in an organism's life cycle - Involved in sexual reproduction
_______________ determine gender and traits that are gender specific, while ___________ determine all other traits.
Sex chromosomes, autosomes
Explain sexual reproduction and how it contributes to genetic variation.
Sexual reproduction is the process by which two gametes fuse and offspring that are a genetic mixture of both parents are produced. Sexual reproduction provides genetic diversity because the sperm and egg that are produced contain different combinations of genes than the parent organisms.
Explain how gender is determined.
The gender of a human is determined by the 23rd pair of chromosomes. These are called the sex chromosomes X and Y. All other non gender determining chromosomes are known as autosomes.
