Answer:
Homologous pairs of chromosomes are lined up independently of other such pairs during <u>metaphase I.</u>
Explanation:
Meiosis is a special type of nuclear division that occurs only in organisms with sexual reproduction. The meyotic division gives rise to gametes.
The division begins just after the chromosome DNA has replicated in the S phase. Each chromosome is made up of two identical sister chromatids joined by their centromere. However, chromosomes are not kept separate in the nucleus, but instead bind to their homologous partners. This union called synapse, occurs during prophase I.
In metaphase I, the pairs of chromosomes are aligned in the spindle Ecuador, that is, during this stage, the homologous pairs are aligned in the metaphase plate (which is the equatorial plane of the achromatic spindle) for separation.
During anaphase I, the members are directed to the opposite poles of the cell. Telophase I, this phase begins with the arrival of chromosomes at the poles and with the formation of a nuclear envelope around each group of chromosomes. During Profase II, the nuclear membrane (if formed during Telophase I) dissolves, and spindle fibers appear.
The first meyotic metaphase and anaphase is usually completed in a short time to give rise to the phases of the second division (metaphase II and anaphase II) , which is a mitosis during which the centromeres divide and the chromatides move towards opposite poles to become gamete chromosomes. In telophase II, cytokinesis separates cells.
We would need more details. Do you need to follow a rubric? Do you have any specific rules? Exactly what about global warming? How long of an essay? What’s the minimum and maximum about of pages. Is this typed, or written? Is there any specific information you’ve learned this unit that you need to include?
Answer:
A
Explanation:
I think it is A because of there being cell walls
Mammalian fertilization comprises sperm migration through the female reproductive tract, biochemical and morphological changes to sperm, and sperm-egg interaction in the oviduct. Recent gene knockout approaches in mice have revealed that many factors previously considered important for fertilization are largely dispensable, or if they are essential, they have an unexpected function. These results indicate that what has been observed in in vitro fertilization (IVF) differs significantly from what occurs during “physiological” fertilization. This Review focuses on the advantages of studying fertilization using gene-manipulated animals and highlights an emerging molecular mechanism of mammalian fertilization.
Sugar-phosphates and nucleotides
