Question: What occurs in prophase 1 of meiosis?

During prophase I, homologous chromosomes pair and form synapses, a step unique to meiosis. The paired chromosomes are called bivalents, and the formation of chiasmata caused by genetic recombination becomes apparent. Chromosomal condensation allows these to be viewed in the microscope. What happens during prophase 1 of meiosis? Meiosis I, the first meiotic division, begins …

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Does crossing over make gametes?

When crossing over occurs between two non-sister chromatids, cells will make equal numbers of recombinant and parental gametes. What does crossing over produce? Crossing-over is the exchange of genetic material between homologous chromosomes. It results in new combinations of genes on each chromosome. … It results in gametes that have unique combinations of chromosomes. In …

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Question: What are duplicated doubled chromosomes called?

The process of creating two new cells begins once a cell has duplicated its chromosomes. In this state each chromosome consists of a joined pair of identical replicas called chromatids. What are doubled chromosomes called? The replicated chromosomes have an X shape and are called sister chromatids. The sister chromatids are pairs of identical copies …

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Your question: What causes changes in chromatin structure?

A major mechanism in the epigenetic regulation of chromatin is the post-translational modification of histone proteins. Mutation or deregulated expression of histone modifying or de-modifying enzymes can lead to altered deposition of modification marks. What affects chromatin structure? Variations in the primary structure of histones H2A and H2B are likely to alter the compaction of …

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Best answer: How many possible kinds of gametes are produced when there is no crossing over?

Assume no crossing-over occurs. Sixteen different combinations. How many different gametes are formed without crossing over? During meiosis without crossing over, the alleles of two genes located on each chromosome migrate together and stay attached. We obtain, therefore, gametes that are 100% “parental”, subdivided into two types of gametes from the point of view of …

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What benefits can you get if your child has autism?

If your child or a loved one’s child has autism, then they could be eligible for monetary payments from the Social Security Administration (SSA) in forms of Social Security disability benefits. The SSA gives out monthly benefits to those. How much money do you get for having an autistic child? While many children with autism …

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What are the various stages of mitosis?

Today, mitosis is understood to involve five phases, based on the physical state of the chromosomes and spindle. These phases are prophase, prometaphase, metaphase, anaphase, and telophase. What are the 4 stages of mitosis and what happens in each? 1) Prophase: chromatin into chromosomes, the nuclear envelope break down, chromosomes attach to spindle fibres by …

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Are meiosis cells 2n?

Meiosis produces 4 haploid cells. Mitosis produces 2 diploid cells. The old name for meiosis was reduction/ division. Meiosis I reduces the ploidy level from 2n to n (reduction) while Meiosis II divides the remaining set of chromosomes in a mitosis-like process (division). Is meiosis 2n or 4N? Germ cells (sperm and egg) are haploid, …

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