The reduction in chromosome number occurs during <u>meiosis I.</u>
Chromosomes are long molecules of DNA that contain some or all of an organism's genetic material. In most chromosomes, very long, thin strands of DNA are coated with packaging proteins. In eukaryotic cells, the histones are the most important of these proteins.
Within the nucleus of all cells, DNA molecules are packaged into thread-like structures called chromosomes. Each chromosome is made up of DNA tightly wrapped many times around proteins called histones that support its structure.
Another type of cell division, meiosis, ensures that humans have the same number of chromosomes from generation to generation. This is a two-step process in which the number of chromosomes is halved from 46 to 23 to form sperm and eggs.
Learn more about chromosomes here:-brainly.com/question/11912112
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Answer:
Wegener thought all the continents were once joined together in an "Urkontinent" before breaking up and drifting to their current positions. But geologists soundly denounced Wegener's theory of continental drift after he published the details in a 1915 book called "The Origin of Continents and Oceans." Part of the opposition was because Wegener didn't have a good model to explain how the continents moved apart.
Explanation:
Answer:
Variation traits and natural selection.
Explanation:
Darwin stated that all species of organisms arise and develop through natural selection and inheritance of variations
In natural selection, survival was for the fittest. In order for an organism to survive . It had to develop new traits to adapt to its environment .
The variation increases its ability to compete, survive and reproduce. Through reproduction the desires trait is passed down making the organism to be considered fit.
Answer:
B) The conclusion is not valid; there were fewer bacteria cultures on the soap plates
Explanation:
In a recent experiment, anti-bacterial hand sanitizer was compared to hand soap. Students washed their hands using the sanitizer or soap and warm water for two minutes; then they dried their hands with a paper towel. The standard of comparison was rubbing hands vigorously for 2 minutes in warm water, without any soap or sanitizer, and then drying with a paper towel. The sanitizer advertisement claimed to kill bacteria more effectively than any soap. After washing, hands were swabbed and then the swab applied to a culture plate and incubated. Finally, the bacterial cultures were counted and recorded in the data table. Students concluded that the hand sanitizer was most effective in killing bacteria. How would you respond to the students' conclusion?
Hand Washing Test Hand Washing Test
Treatment Bacterial cultures (#/plate)
Warm water 24
Hand sanitizer 28
Soap A 12
Soap B 13
The above table should have been included before the question. From the table we can conclude that
B) The conclusion is not valid; there were fewer bacteria cultures on the soap plates
Which also means that the sanitizer is not as effective as warm water. it is the least effective solution to kill bacterial.
