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
Having two sets of chromosomes is known as (2n) _______diploid___________. ANSWER: 6. Eggs and sperm are _______haploid_________ (n). ANSWER: Next Give one characteristic of each of the following phases of Meiosis I. Prophase I: During prophase I, homologous chromosomes pair and form synapses, a step unique to meiosis Metaphase I: Bivalents, each composed of two chromosomes align at the metaphase plate Anaphase I: Each of the daughter cells is now haploid Telophase I: Nuclear envelopes may reform 7. Does the S phase (DNA replication) occur after Meiosis 1?
3.0 Chromosomal structure provides the key to inheritance The evidence that chromosomes contain hereditary material on genes, which is passed on to successive generations, is important to our understanding of life. It is well known that it is the sequence of nucleotides on the DNA that carries the genetic information, and that mutations are caused by changes in DNA structure. Mendel’s laws: Law of segregation Inherited characteristics are controlled by genes that occur in pairs. Each gamete contains one gene from each pair. The offspring therefore will regain a gene pair (one from each parent).
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. | A process of asexual reproductionin which the cell divides in two producing a replica, with an equal number of chromosomes in haploid cell | Function: | sexual reproduction | Cellular Reproduction & general growth and repair of the body | Type ofReproduction: | Sexual | Asexual | Occurs in: | Humans, animals, plants, fungi | all organisms | Genetically: | different | identical | Crossing Over: | Yes, mixing of chromosomes can occur. | No, crossing over cannot occur.
10. Describe how the “packaging” of DNA to form a chromosome occurs. How many chromosomes does a human cell have? Why are there chromosome pairs? What are the sex chromosomes for a female?
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.
Females have two x chromosomes and males have an x and a y. Genes are portions of DNA that perform one function and are passed down to the next generation. Genes are given names to identify them. The gene that is responsible for Fragile-X-syndrome is named FRM1. The FRM1
The long, thin ascus causes both meiotic spindles and the mitotic spindles to be aligned during spore formation. As a result, the positioning of the ascospores directly reflects the arrangement of homologous chromosome pairs during metaphase I of meiosis (Glase, 1995). This allows us to detect which alleles were exchanged creating crossovers. Sexual reproduction in the S. fimicola is important because an it allows for a significant source of genetic variability, and allows the fungus to adapt to new environments (Fincham, 1971). This genetic variability is obtained when crossovers occur between
What about identical twins that are separated at birth but yet have strikingly similar views, preferences, tastes and abilities? The only feasible explanation is that these traits are biological in nature. Could this be said for all factors that make up our own individual personalities? This essay will explain why biology can be a rational explanation for these traits using examples from current and past research and from theoretical evidence. The study of the human genome project has allowed for the complete sequencing of human DNA for the first time.
100% long eyelashes C. 75% long, 25% short B. 75% short, 25% long D. 100% short 3. Varieties of plants or animals that when crossed with each other always produce offspring that are identical to themselves are: A. true-breeding B. heterozygous C. homozygous D. F1 hybrids E. A and C 4. How many different kinds of gametes can be produced by an individual with the genotype AABbCCddEeFf? A.