What is meant by homozygous and heterozygous? Homozygous→ When the alleles from both parent are the same. Heterozygous→ When the alleles from both parents are different. 21. What did Gregor Mendel contribute to the study of biology and what 7 plant traits did he study?
Hybridization- crossing different traits to bring the best of organisms into one. For example crossing disease resistance of one plant with the food-producing capacity of another to produce a superior plant. 3)Cloning is the process of taking a single cell from an adult organism to recreate another genetically identical organism. 4)DNA fingerprinting is developed by molecular biology; it analyzes unique sections made up of a variety of DNA band. DNA fingerprinting is a powerful and crucial tool that can determine a person’s identity.
Genetics can simply be defined as the study of heredity. Heredity is the biological process where a parent passes certain genes to their offspring. In our laboratory, our group mated fruit flies to witness Mendel’s laws and heredity in action. “The genetic instructions to build a fruit fly-or any other organism-are imprinted in its DNA, a long, threadlike molecule packaged in bundles called chromosomes. Each chromosome consists of many individual sections called genes.
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.
1) Monocots are shorts for “Monocotyledons” which means plants whose embryo has one cotyledon; whereas, Eudicots (Eudicotyledons) carry embryo with 2 cotyledons. The cotyledons of eudicots supply nutrients for seedlings, but the cotyledons of monocots store some nutrients and act as a transfer tissue for nutrients stored elsewhere. Five key features are typically used to distinguish monocots from eudicots; a seed, arrangement of vascular tissue in roots, stems, and leaves, and number of flower parts. The seed has the reproductive structures that are protected from drying out, have male and female gametophytes which are reduced in size. In young dicot stems and stems (usually the upright, vertical portion of a plant transports substances to and the leaves) that do not increase in thickness, xylem and phloem are arranged in vascular bundles in the cortex.
The reproductive cycle of vascular plants compared to humans All sexually reproducing organisms have an alternation of generations. One way that the reproduction cycle of vascular plants compares to the reproduction of humans is that both organisms pass through a haploid and a diploid stage in their life cycle. The diploid state in humans is us and the haploid state is the gamete which is the sperm and egg. Individuals produce all of the gametes. The diploid state in plants is known as sporophyte which produces spores and the haploid state in plants is known as gametophyte which produces gametes.
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
3) What does the taproot system do? Often stores organic nutrients that the plant consumes during flowering and fruit production. 4) Why are root crops such as carrots, turnips, and sugar beets harvested before they flower? Because the taproot system stores organic nutrients in the root part. 5) What is the system where no roots stand out as the main one?
What is the benefit of the modification? Because the GM tomatoes can remain fresh longer they have time to ripen in the sun before picking, resulting in a better tasting tomato! 4. Three advantages of genetically modified foods Longer lasting foods can be more easily transported, Having extra vitamins in food help poor people from becoming malnourished or going blind, and the insecticides inside some genetically modified plants keep farmers from having to spray the whole place down with toxic wastes, and they also 5. A counter argument to one of the disadvantages of genetically modified food Some antibiotics can be transferred to humans and make it harder for us to fight infections, genetically modifying foods could potentially put farmers out of work, and some important insects could be at risk because of the insecticides in foods.
Individuals within a population may survive if they have an inherited trait that gives them a selective advantage. They can then go on to reproduce and pass on their advantage to their offspring. Agricultural crops are seletivly bred for different characteristics such as being drought-resistant or pre-resistant. However, selective breeding comes at the expense of decrease variation. Decreased variation leads to a reduced ability to respond to a changing environment.