Answer:A genotype is the combination of two alleles, one received from each parent. The expression of a genotype is called the phenotype and the specific combination of the two alleles (the genotype) influences the physical expression (the phenotype) of the physical trait that the alleles carry information for.
Explanation: so 2
Brains of alzheimer victims display plaque, which are BETA AMYLOID PROTEIN and tangles, which are TAU PROTEIN. Alzheimer is a neuro-degenerative disease in which brain cells are progressively destroyed, leading to memory loss and dementia.
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In bryophytes, the sporophyte is minute and dependent on the relatively prominent and nutritionally independent gametophyte for resources. The moss gametophyte looks like a miniature herb, with tiny leaf-like photosynthetic organs. The gametophyte generation begins as a dormant spore, which germinates under appropriate conditions to produce filamentous and branching protonemal tissues. These form multicellular bud-like structures, each of which develops into a leafy shoot. The mature gametophytes produce male and female sexual organs, the antheridia and archegonia, respectively. The gametophyte is often sexually distinct, and plants are either male or female.
Each antheridium has an outer layer that encloses and protects thousands of motile sperm, which swim through available external water layer to the egg. Fertilization at the base of the cylindrical archegonium produces a diploid zygote which develops into an unbranched sporophyte. The sporophyte consists of a thin stalk attached to the gametophyte, and a capsule that encloses the sporophytic meiotic cells.
In recent years, the mosses Physcomitrella patens and Funaria hygrometrica have emerged as attractive model systems for studying gene function in non-vascular plants because of the relative ease of molecular manipulation by homologous recombination. Mutants affecting gametophyte development have been isolated and their analysis should provide insights into the molecular basis of gametophyte development in mosses.
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Option A, oxygen in the atmosphere
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The highest level of oxygen reached during this phase of the geological cycle of earth. The oxygen level in Carboniferous period accounted for 35% as compared to 21% of oxygen in the atmosphere in present time.
Due to high oxygen content, the giant and wide varieties of terrestrial animal and plant species evolved. For example – size of insects and carwlies increased, plant became extremely giant, increase in number of tree ferns etc.
Answer: The colors you see in flowers come from the DNA of a plant. Genes in a plant's DNA direct cells to produce pigments of various colors. When a flower is red, for instance, it means that the cells in the petals have produced a pigment that absorbs all colors of light but red.
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