Meiosis is a process in which the number of chromosomes per cell is cut in half through the separation of homologous chromosomes in a diploid cell. Meiosis usually involves two distinct divisions called meiosis I and meiosis II. By the end of meiosis, a single diploid cell has produced four haploid cells. After interphase I, the cell begins to divide, and the chromosomes pair up. In prophase 1 of meiosis, each replicated chromosome pairs with its corresponding homologous chromosome. This pairing forms a structure called a tetrad, which contains four chromatids. As the chromosomes pair, they sometimes undergo a process called crossing-over.

Which is a true statement of crossing-over?

A. Homologous chromosomes move to opposite ends of dividing cells

B. During crossing-over, bits and pieces of the homologous chromosomes are exchanged

C. The DNA of the diploid cell is copied

D. Crossing over decreases genetic diversity

The diagram below represents a marine food web and a process that can harm the human population. each circle represents an organism and the smaller dots inside them represent a toxic substance. what is being represented and how does it harm the population? the diagram represents biological half-life, in which toxins build up in organisms higher up on the food chain, and this can negatively impact humans who consume the organisms and the toxic substance. the diagram represents biomagnification, in which toxins build up in organisms higher up on the food chain, and this can negatively impact humans who consume the organisms and the toxic substance. the diagram represents the process by which different organisms prey upon each other; this can impact the human population by reducing the number of organisms that do not contain the toxin. the diagram represents the way that toxins are metabolized by living organisms, with those at greater trophic levels able to metabolize more efficiently than those at lower levels. this means that those at higher tropic levels are safer for humans to consume compared to the organisms at lower trophic levels.

Getting out of bed is the first goal i tackle each day. 2several small goals are achieved by me as the day progresses. 3when i am riding the bus home or walking the dog, i think about the bigger goals i have for my life. which statement correctly describes the verb tense, aspect, and voice in this paragraph? a. sentences 1 and 2 contain present progressive verbs. sentence 3 contains both present progressive and simple present verbs. sentence 2 uses passive voice. b. sentences 1 and 2 contain simple present verbs. sentence 3 contains present progressive verbs. all three sentences use active voice. c. sentences 1 and 2 contain present progressive verbs. sentence 3 contains simple present verbs. all three sentences use active voice. d. sentences 1 and 2 contain simple present verbs. sentence 3 contains both present progressive and simple present verbs. sentence 2 uses passive voice.

Drag each tile to the correct box. arrange the phases of mitosis in the correct order. 1 (condensation of chromosomes) 2 (separation of chromosomes) 3 (formation of spindle fibers) 4 (alignment of chromosomes in the center of the cell) 5 (pinching of the cell membrane)