Answer:
<u>a) strong joints with restricted movement.</u>
Explanation:
Joints which are closely fitted cannot allow free movement because movement requires space in the joint so the bones can move in this space. So a closely fitted joint allow restricted or no movement at all. Weak joints with restricted movements are called weak because they are not well fitted closely. Strong joints with restricted movement is closely fitted, one of the example is joints of skull.
Before a cell goes through cell division (mitosis), it must grow and make a copy of its DNA which is termed as an Inter-phase.
<u>Explanation:</u>
Some tasks must be carried out by the cells before they undergo division: The cell must grow, it must copy the genetic material (DNA) present in it, and divide into two daughter cells. These steps carried out by cells are termed as cell cycle.
Cells that contains a nucleus or Eukaryota cells, there are two major phases called interphase and the mitotic (M) phase. that comprises the cell cycle.
In inter-phase, growth of the cell and making a copy of its DNA is carried out.
In mitotic (M) phase, the cell separation of the DNA in the cell into two sets and division of its cytoplasm takes place resulting in the formation of two new cells.
1) Interphase is the longest phase and most of the cells are present in that very stage !!
2) Interphase is the longest phase and Anaphase is the shortest phase !! Interphase is the longest phase as in this phase the cells prepare themselves for dividing and it takes most of the time for gathering energy for division ; in this phase DNA also replicate !!
3)
Interphase: DNA replicates;
Prophase: Nuclear membrane starts disappearing and Centrioles go on opposite poles !! DNA condense to form Chromosome.
Metaphase: Chromosome attach to spindle fibre and starts to move to equitorial plate.
Anaphase: Centromere divide and half the chromatid goes on either pole
Telophase: Nuclear membrane starts to reassemble; Chrmosome goes to normal uncoiled state ; Other organelles starts appearing
Cytokinesis: Cell furrow forms and cell divides into two half.
4) In dividing cell nucleus membrane is absent while in non dividing cell the membrane is intact
5) Tip of the onion root is meristamatic cell which divides but if it is permanent cell ; there would be no division !!
Question: Below is a list of functions performed by organisms. Examine the list, then answer the question that follows.
gas exchange
intake of nutrients
disposal of wastes
stimulus response
reproduction
How do these functions compare between single-celled and multi-celled organisms?
A. Single-celled organisms can perform all of these functions, while multi-celled organisms can perform only some of these functions.
B. Single-celled organisms must perform all of these functions with one cell, while multi-celled organisms can have specialized cells for different functions.
C. Single-celled organisms can perform only some of these functions, while multi-celled organisms can perform all of these functions.
D. Neither single-celled organisms nor multi-celled organisms can perform all of these necessary functions.
Answer:
Option B, Single-celled organisms must perform all of these functions with one cell, while multi-celled organisms can have specialized cells for different functions.
Explanation:
All these functions are performed by both single celled and multi-cellular organism. A single cell has several microscopic organelles that performs specific functions while a multi - celled organism has different body organs/tissues to perform specialized function separately.
A cell exchange gas through the cellular membrane, intake nutrients through engulfing, dispose waste by lysosomes, stimulus response by sensory hairy structure and reproduction through cell division
Hence, option B is correct.
Answer:
1. El corazón se localiza en el mediastino, que es el espacio comprendido entre ambos pulmones. 2. El miocardio es la capa funcional del corazón, puesto que su contracción impulsa la sangre hacia los pulmones y los demás tejidos. 3. Internamente el corazón presenta 4 cavidades: 2 cavidades superiores llamadas auriculasy dos cavidades inferiores conocidas como ventriculos . 4. Entre la aurícula y ventrículo del mismo lado se encuentran las válvulas auriculoventriculares. En el lado derecho tenemos la válvula tricuspide, mientras que en el lado izquierdo se encuentra la válvula mitral . 5. El ciclo cardiaco comprende dos fases, una de contracción o sistole y una de relajación llamada diastole.
Explanation:
El corazon es un organo con un tejido muscular liso especializado donde estas celulas musculares presentan uniones desmosomales de amplia conexion para la diseminacion rapida de señales, es asi como se producen contracciones ritmicas, autonomas y de manera simultanea.
El corazon a su vez presenta su auto irrigacion propia por medio de las arterias coronarias que se encargan de mantener el miocardo en buen estado de vitalidad.
