Amber Chu - Cell Web Research PDF

NOTE: THIS IS FOR MARKS!!!!! Total = /20 Cell Web Research Name: __Amber Chu_________________________ Date: ___28thOctober,2021__________________________ Your task is to research cells. Be careful to make sure that you are view...

NOTE: THIS IS FOR MARKS!!!!! Total = /20 Cell Web Research Name: __Amber Chu_________________________ Date: ___28thOctober,2021__________________________ Your task is to research cells. Be careful to make sure that you are viewing reliable sources. If you have questions, ask the teacher. Use the following websites to guide your research and answer the questions in the space provided. ​ http://www.biology4kids.com/files/cell_main.html ​ http://www.kidsdiscover.com/spotlight/kids-cells/ ​ https://kids.britannica.com/kids/article/cell/352933 1.​ Use the above sites to help answer the following three questions. a)​ What is found in the middle of the cell? Why is this important? /2 The nucleus is found in the middle of the cell. This is important because it acts as the control centre of the cell and it regulates the cell’s growth and reproduction. b)​ Why are chromosomes important? What is their function and where do they come from? Chromosomes are important because they contain the cell’s genes which determine the characteristics of the cell. Their function is to hold the cell’s genes. They come from the nucleus. /2 c)​ Describe the steps involved in cell division. (You may create drawings to help describe the steps).  First, DNA condenses to form chromosomes. They split, forming two identical chromatids. Each pair is then divided into two cells during the division of the nucleus. There are 5 phases of mitosis. First, the mitotic spindle forms, and the chromosomes condense. Then, the nuclear envelope breaks down. The chromosomes attach to the mitotic spindle. Both chromatids of each chromosome attach to the spindle at a specialized chromosomal region. Next, the condensed chromosomes align in a plane across the equator of the mitotic spindle. After that, the separated chromatids move abruptly toward opposite spindle poles. Lastly, in telophase a new nuclear envelope forms around each set of unraveling chromatids. Eytokinesis happens next. For animal cells, it is achieved through the constriction of the cell by a ring of contractile microfilaments. For plants cells, the cytoplasm is divided by the formation of a new cell wall. It arises from small Golgi-derived vesicles to form a disk-shaped structure. The second set of vesicles extends the edge of the cell plate until it reaches and fuses with the sides of the parent cell, thereby completely separating the two new daughter cells. Lastly, Meiosis happens during the formation of the reproductive cells of sexually reproducing organisms. Gametes begin as having two copies of each gene in their nuclei. The chromosomes composed of these matching genes are homologs. During DNA replication, each chromosome duplicates into two attached chromatids. The homologous chromosomes are separated to opposite poles of the meiotic spindle by microtubules similar to those of the mitotic spindle. At this stage in the meiosis of germ cells, there is a difference from the mitosis of other cells. In meiosis, the two chromatids making up each chromosome remain together, so that whole chromosomes are separated from their homologous partners. Cell division then occurs, followed by a second division that resembles mitosis more closely in that it separates the two chromatids of each remaining chromosome. In this way, when meiosis is complete, each mature gamete receives only one copy of each gene instead of the two copies present in other cells.  1.​ What English scientist first described cells? What did this scientist look at? Robert Hooke first described cells. This scientist looked at a piece of cork. /2 2.​ What distinguishes a plant cell from an animal cell? A plant cell has a protective structure called a cell wall made of cellulose to protect the cell membrane. A plant’s cell walls make the plant stiff enough to grow tall. They have chloroplasts in their cells. Plants also have organelles such as the green chloroplast or large, water-filled vacuoles. Animal cells don’t have that. Animal cells don’t have cell walls and don’t contain chloroplasts. /2 3.​ Where might mitochondria have originated from? Why? Mitochondria might have originated from bacteria that eventually entered a symbiotic relationship with other cells because they contain their own DNA, separate from the rest of the genes in a cell. /2 4.​ What makes E.R. rough? The ribosomes assembling the proteins that are destined to be part of the cell membrane or exported from the cell attach to the endoplasmic reticulum, giving it a rough appearance. /1 5.​ Choose either a plant or an animal cell. Draw this cell in the space provided and label only FOUR organelles. Include a brief description of the organelle’s function. /5​ Red: Mitochondria- Produces energy Orange: Central Vacuole-Reservoir, waste dump, storage region Green: Nucleus-controls and regulates the activities of the cell Pink: Cell wall- give the cell strength and structure