Gregor Mendel

1. Gregor Mendel Quiz and photos

2. Gregor Mendel was: • an English scientist who carried out research with Charles Darwin • a little known Central European monk • an early 20th century Dutch biologist who carried out genetics research

3. B is CORRECT He worked in virtual obscurity during the mid 19th century. Unfortunately, Charles Darwin did not know of Mendel`s work. He was one of the few scientists of that time who might have understood and appreciated Mendel`s huge contribution to science.

4. Which statement is true about him? • His discoveries concerning genetic inheritance were generally accepted by the scientific community when he published them during the mid 19th century. • He believed that genetic traits of parents will usually blend in their children. • His ideas about genetics apply equally to plants and animals.

5. C is CORRECT He gave us the basis for understanding genetic inheritance in all living things, including humans. His realization that we inherit units or genes was the key to it all.

6. Mendel believed that the characteristics of pea plants are determined by the: • inheritance of units or factors from both parents • inheritance of units or factors from one parent • relative health of the parent plants at the time of pollination

7. A is CORRECT We now call these units genes. Each inherited trait is determined by at least one gene from each parent.

8. An allele is: • another word for a gene • a homozygous genotype • a heterozygous genotype • one of several possible forms of a gene

9. D is CORRECT An allele is one of two or more alternate forms of a gene. If an individual is homozygous (YY or GG) for a trait, it has inherited the same allele from both parents. If it is heterozygous (YG), it has inherited different alleles for the trait.

10. Phenotype refers to the ______________________ of an individual. a) genetic makeup b) actual physical appearance c) recessive alleles

11. B is CORRECT Phenotype is the observable characteristics, including physical appearance. It results from the genotype and environmental influences. A phenotype includes not only easily measured traits like hair color but also less apparent ones such as blood type.

12. When the genotype consists of a dominant and a recessive allele, • the phenotype will be like the dominant allele. • the phenotype will be like the recessive allele. • the phenotype will be neither like the dominant nor the recessive allele.

13. A is Correct The dominant allele masks the appearance of the recessive one. However, there are some traits for which this simple rule of dominance does not apply.

14. Assuming that both parent plants in the diagram below are homozygous, why would all of the f1 generation have yellow phenotypes? a) because the f1 genotypes are homozygous b) because yellow is dominant over green c) because both parents passed on yellow alleles

15. B is correct When there is a genotype that consists of a dominant and a recessive allele, the phenotype generally looks like the dominant one. In this case, yellow is dominant.

16. The idea that different pairs of alleles are passed to offspring independently is a)Mendel's principle of unit inheritance b)Mendel's principle of segregation c)Mendel's principle of independent assortment

17. C is Correct This is a definition of his principle of independent assortment. Stated in other words, the genes that determine a trait assort independently of the genes for other traits. As a result, new combinations of genes, present in neither parent, are possible.

18. The idea that the pair of alleles of each parent separate and only one allele from each parent passes to an offspring • is Mendel's principle of independent assortment b)is Mendel's principle of hybridization c)is Mendel's principle of segregation

19. C is correct This is the definition of the principle of segregation. Stated in other words, genes occur in pairs and during the process of sex cell production, the members of each pair separate so that each sperm and ovum cell receives one member of each pair.

20. Task: Definition of terms Pollination Unit genes Homozygous genotypes Heterozygous genotypes Allele (dominant and recessive) Phenotype Independent Assortment Segregation Hybridization

21. Pollination the process that transfers pollen grains, which contain the male gametes (sperm) to where the female gamete(s) are contained within the carpel

22. Unit Gene A gene is a unit of Heredity

23. Allele (from the Greek αλληλος allelos, meaning each other) is one member of a pair or series of different forms of a gene. Usually alleles are coding sequences. An individual's genotype for that gene is the set of alleles it happens to possess. In a diploid organism, one that has two copies of each chromosome, two alleles make up the individual's genotype.

24. Zygosity • It refers to the genetic condition of a zygote. In genetics,it describes the similarity or dissimilarity of DNA between homologouschromosomes at a specific allelic position. • Zygosity is also used to describe the genetic condition of the zygote(s) from which twins emerge, where it refers to the similarity or dissimilarity of the twins' DNA. Identical twins are monozygotic - Fraternal twins are dizygotic.

25. Zygosity • The terms homozygous, heterozygous and hemizygous are used to simplify the description of the genotype of a diploid organism at a single genetic locus. • Diploid organisms generally have two alleles at each locus, one allele for each of the two homologous chromosomes. • Homozygous describes two identical alleles or DNA sequences at one locus, heterozygous describes two different alleles at one locus, and hemizygous describes the presence of only a single copy of the gene in an otherwise diploid organism.

26. Homozygous genotypes Occurs when both alleles at a particular gene locus are the same.

27. Heterozygous Genotype Occurs when the two alleles at a particular gene locus are different. A heterozygous genotype may include one normal allele and one mutation, or two different mutations. The latter is called a compound heterozygote.

28. Phenotype Any observable characteristic of an organism, such as its morphology, development, biochemical or physiological properties, or behavior. Phenotypes result from the expression of an organism's genes as well as the influence of environmental factors and possible interactions between the two.

29. Independent assortment* Mendel's law of independent assortment, states that allele pairs separate independently during the formation of gametes. This means that traits are transmitted to offspring independently of one another. *Assortment : separation into classes

30. Segregation* allele pairs separate or segregate during gamete formation, and randomly unite at fertilization * To segregate: to separate or isolate from the main body or group

31. hybridization Production of a hybrid by pairing complementary ribonucleic acid and deoxyribonucleic acid (DNA) strands. Production of a hybrid by pairing complementary DNA single strands