How does natural selection change the frequency of genes or traits over many generations? Biology students conducted an experiment mimicking genetic variation and coloration. Students used different colored beans to represent animals that might be prey: mice, for example. A student in each group was the predator: a hawk. Beans (mice) were randomly scattered on multicolored floor tiles, each color within four tiles. The hawk collected mice (beans) for 10 seconds. Mice not eaten reproduced. Three generations of data a shown in the table. Genetic variation helps to drive natural selection and potentially, evolution. Red, white, and striped beans (mice) represent offspring that are the product of meiosis and sexual reproduction. Black and speckled beans (mice) are the result of mutations. Using the student data analyze the effects of these mutations on natural selection.

A) The color mutations provided a survival advantage to these two populations of mice.

B) The advantage of the mutations is dependent on the environment and external conditions.

C) While mutations provide genetic variation they did not play a role in natural selection.

D) The speckled mutation provided an advantage while the black mutation was a disadvantage for survival.


D) The speckled mutation provided an advantage while the black mutation was a disadvantage for survival.

fertilization, pictured in figure 24.23a is the process in which gametes (an egg and sperm) fuse to form a zygote. the egg and sperm each contain one set of chromosomes. to ensure that the offspring has only one complete diploid set of chromosomes, only one sperm must fuse with one egg. in mammals, the egg is protected by a layer of extracellular matrix consisting mainly of glycoproteins called the zona pellucida. when a sperm binds to the zona pellucida, a series of biochemical events, called the acrosomal reactions, take place. in placental mammals, the acrosome contains digestive enzymes that initiate the degradation of the glycoprotein matrix protecting the egg and allowing the sperm plasma membrane to fuse with the egg plasma membrane, as illustrated in figure 24.23b. the fusion of these two membranes creates an opening through which the sperm nucleus is transferred into the ovum. the nuclear membranes of the egg and sperm break down and the two haploid genomes condense to form a diploid genome.

explanation:

answer: glucoamylase presented optimum activity at temperature of 55â°c, and, in the glycosidic bonds from the non-reducing ends of starch, resulting in the production of glucose. source and type of fermentation can affect the enzyme's properties

credit to kalahira

1: most common garden plants prefer loam — soils with a balance of different-sized mineral particles (approximately 40% sand, 40% silt, and 20% clay) with ample organic matter and pore space. however, some plants grow better in sandy soils, while others are well-adapted to clay soils.

2: available water capacity is the maximum amount of plant available water a soil can provide. it is an indicator of a soil's ability to retain water and make it sufficiently available for plant use. available water capacity is the water held in soil between its field capacity and permanent wilting point.

3: it is the same for all living things (plants and animals). it also includes very tiny organisms that our eyes cannot see. they are known as microorganisms, and include viruses, bacteria and fungi.