Chapter 13, 14 Flashcards
what are genes?
Gene in an organism ‘s specific locus on a certain chromosome.
what are genes?
Gene in an organism ‘s specific locus on a certain chromosomes
What is an karyotype
The resulting ordered displayed for chromosomes.
What is an karyotype
The resulting ordered displayed
What is a sexual reproduction?
Combines sets of genes from two different parents, leading to genetically diverse offspring.
What Are diploid?
Normal human somatic cell are diploid. They have 46 chromosomes made up of two sets of 23 - one set from each parent.
What are in an human diploid cell?
22 homologous pairs of autosomes each with a maternal and paternal homolog.
What is an sex chromosome?
The 23rd pair determines whether the person is a female (XX) or male (XY).
What occurs in a sexual maturity life cycle?
Ovaries and Testes (the gonads) produce haploid gametes by meiosis each gamete containing single set 23 chromosomes.
What occurs during fertilization?
An egg and sperm unite, forming a multicellular organism by mitosis.
How is a zygote form?
Egg and sperm unite producing an diploid, which develops into a multicellular organism by mitosis.
What occurs in meiosis?
meiosis reduces the number of chromosome sets from diploid to haploid.
What occurs in meiosis 1 and meiosis 2?
produce four haploid daughter cells
How is meiosis distinguished from mitosis in 3 events of meiosis?
> Prophase I: Each homologous pair undergoes synapsis and crossing over between non sister chromatids with subsequent appearance of chiasmata.
Metaphase1 : Chromosomes line up as homologous pairs on the metaphase plate.
Anaphase 1: Homologs separate from each other; sister chromatids remain joined at centromere.
What happens in Meiosis 2?
sister chromatids separate
What happens in Meiosis 2?
sister chromatids seperate
What are the three events in a sexual reproduction to contribute to genetic variation in a population?
> independent assortment of chromosomes during meiosis
Crossing over during meiosis1
random fertilization
What occurs in recombinant chromosomes?
When crossing over involves breakage and rejoining of DNA of nonsister chromatids in homologous pair result in recombinant chromatids that will become recombinant chromosomes.
What is law of segregation?
It is stated that genes have alternative forms of alleles. in diploid organism, the two alleles of gene separate during meiosis and gamete formation each sperm or egg carries only one allele of each pair.
What is heterozygotes?
The two alleles are different, expression of one dominant and recessive one that mask phenotypic effect of the other.
What is heterozygotes?
The two alleles are different, expression of one dominant allele.
What are homozygotes?
identical alleles of a given gene that are true breeding.
What is the law of independent assortment?
States that pairs of alleles for a given gene separates into gametes independently of the pairs of alleles of any other gene. In a cross between individuals heterozygous for genes, the off spring have four phenotypes in 9:3:3:1 ratio.
What are the laws of probability govern mendelian inheritance?
Multiplication rule: states that the probability of two or more events occurring together is equal to the product of the individual of the independent single events.
Addition rule: states that probability of an event that can occur in two or more independent, mutually exclusive ways is sum of the individual probabilities.
