Answer:
The answer is - Although their cell structures are very different, archaean and eukaryotic cells are more closely related to each other than to bacteria, as evidenced by the fact that Bacteria was the first domain to split from the shared ancestor of Archaea and Eukarya.
Explanation:
The options are:
A. Bacterial and eukaryotic cells are more closely related to each other than to archaeans, as evidenced by the fact that bacteria and eukaryotes do not inhabit the most extreme environments.
B. Although their cell structures are very different, archaean and eukaryotic cells are more closely related to each other than to bacteria, as evidenced by the fact that Bacteria was the first domain to split from the shared ancestor of Archaea and Eukarya.
C. Bacteria and archaeans are more closely related to each other than to eukaryotes, as evidenced by their cell structures. Bacteria and archaeans are prokaryotic, while all eukaryotic cells contain mitochondria and other membrane-bound organelles.
D. The three domains of life are equally divergent from one another, so no two domains are more closely related to each other. This is supported by the evolutionary tree of life because three branches extend from one node millions of years ago.
The answer is - B. Although their cell structures are very different, archaean and eukaryotic cells are more closely related to each other than to bacteria, as evidenced by the fact that Bacteria was the first domain to split from the shared ancestor of Archaea and Eukarya.
Archaea and bacteria are similar in terms of cellular organisation and size but are however similar to eukaryotes (eukarya) at the molecular level. Archaea and Eukaryotes both undergo DNA replication and protein synthesis the same mechanism. Both of them posses closely related genes and several metabolic pathways, including the enzymes in transcription and translation.
Answer: C: Se inhibe (no se desarrolla) la ovulación.
Explanation:
Los métodos anticonceptivos se utilizan prevenir el embarazo no deseado, evitando que el esperma fertilice a un óvulo. Hay distintos tipos, los cuales se clasifican en:
- Anticonceptivos hormonales: Contienen hormonas, tales como estrógeno y progesterona, que previenen la ovulación (es decir, la liberación de óvulos de los ovarios). De esta manera, al no haber óvulo disponible, por mas que hayan espermatozoides, no va a ocurrir ninguna fecundación. El método mas conocido es la píldora o pastilla anticonceptiva.
- Anticonceptivos de barrera: Proveen una barrera física que impide la fecundación al impedir el encuentro entre el óvulo y el espermatozoide. Por ejemplo, el uso de preservativos o condones. En estos métodos, se impide la entrada de los espermatozoides, no se encuentran con el óvulo y la esperma queda atrapada dentro del condón.
- Anticonceptivos permanentes: Proveen un método permanente como por ejemplo el Dispositivo Intrauterino que se coloca en el tracto uterino con una vida media de meses o años y posee un efecto espermicida que mata a los espermatozoides (por lo que no lograrán encontrar un óvulo). Otro ejemplo es la vasectomía, la cual es una cirugía que corta los conductos deferentes que transportan a los espermatozoides por lo que ya no pueden salir de los testículos para producir la fecundación (quedan atrapados dentro de los testículos, no entran al tracto uterino y no encuentran al óvulo)
Tanto los métodos de barrera como los permanentes, no inhiben la ovulación aunque si impiden que el óvulo se encuentre con el espermatozoide. <u>Entonces, los métodos hormonales son los únicos que logran inhibir la ovulación</u>. Las píldoras que poseen las hormonas previamente mencionadas pero fabricadas sintéticamente. Las mismas mimetizan el efecto de las hormonas naturales producidas por el cuerpo, alterando el ciclo menstrual regular y así evitan el embarazo ya que no habrá óvulo disponible para fecundar. Además, también pueden alterarla mucosidad en el cuello del útero para que los espermatozoides no pueden atravesarlo y llegar al óvulo. De todas maneras, el objetivo principal y mas importante de los métodos hormonales es bloquear la ovulación.
The electron transport chain (ETC) is the final step of cellular respiration and takes place in the mitochondrion.
- The final step in cellular respiration is the electron transport chain. This is sometimes abbreviated as ETC. ETC needs oxygen, which means aerobic process. It occurs at the edges of the inner lining of mitochondria. These handles are called cristae.
No system is closed off by it surroundings.
Answer: seen below
Explanation:
In vigorous exercise, your brain and body do everything they can to cool you off by increase the flow of blood to the skin where it can cool down with the aid of sweating , while in someone who has an infection they push the temperature inside your body to extreme levels by strengthening your immune system resistance to the infection, the immune system deliberately raises your body temperature as part of its strategy to kill the infection attacking you.
