| A | B |
|---|
| What are two methods of dealing with cell size? | Altered shape and cell division |
| Why do cells divide? | Heal/repair, for multicellular organisms to grow in size, to increase efficiency for diffusion, unicellular organisms to reproduce |
| Cell division results in? | Results in two cells that are identical to the original, parent cell |
| Chromosomes | "Colored bodies" that contain genetic material; identity of the cell |
| cell cycle | sequence of growth and division of a cell |
| what two parts is the cell cycle broken into? | interphase: growth; and mitosis; division |
| in which stages does a cell spend most of its life in? | INTERPHASE over 90% of its life |
| Cell division occurs during which stage of a cell's life? | mitosis |
| What is cytokinesis? | One final process, division of the cytoplasm, and takes place after mitosis |
| What happens in interphase? | the cell grows in size, carries on metabolism, and replicates chromosomes |
| What is the first phase of interphase? | G1: Chromosomes are not yet visible, rapid protein synthesis due to growth |
| What is the second phase of interphase? | S: Chromosomes are replicated or copied in the nucleus ( sister chromatids) |
| What is the third phase of interphase? | G2: Chromosomes are shorten and coil, protein synthesis prepares for Mitosis, protein synthesis prepareto make the mitotic spindle, cell organelles are replicated |
| How is DNA packaged into chromosomes | DNA coils around a set of 4 histone proteins, creating a "bead on a string" called a nucleosome |
| How is DNA packaged into chromosomes 2? | The nucleosome coils into structures called chromatin |
| Chromatin supercoils= | Chromosome |
| How many chromosomes do humans have in total? | 46 chromosomes |
| What does the M Phase consist of? | Mitosis and Cytokinesis |
| Mitosis | Division of the nucleus |
| Cytokinesis | Division of the cytoplasm |
| Prophase | First and longest stage? |
| What happens to chromatin in prophase? | coil up into visible chromosomes; sister chromatids are visible from interphase; sister chromatids held together centromeres |
| What happens to the nucleus and the nucleolus in prophase? | nucleus begins to disappear and the nucleolus disintegrates |
| Animal cells and prophase | centrioles migrate to the poles for chromatin seperation |
| spindle forms | for sister chromatid seperation |
| Plant cells and prophase | The spindle forms without centrioles |
| Metaphase | short second phase |
| what happens to chromosomes in metaphase | doubled chromosomes become attached to the spindle fibers by their centromers, chromosomes are pulled by the spindle fibers and begin to line up on the midline or equator of the spindle |
| What is each sister chromatid in metaphase attached to? | attached to its own spindle fiber; one spindle fiber extends to one pole, the other to the opposite pole |
| What does the chromatids attaching to spindle fibers ensure in metaphase? | ensures that each new cell receives an identical and complete set of chromosomes |
| Anaphase | Third phase of mitosis |
| What happens in anaphase? | seperation of sister chromatids at the beginning, centromeres split apart |
| What happens to chromatids in anaphase? | chromatid pairs from each chromosomes seperate from each other, chromatids are pulled apart by the shortening of the microtubles in the spindle fibers |
| Telophase | Fourth and final stage (end or death) |
| Where does telophase begin? | Begins as chromatids reach the opposite poles of the cell |
| What happens to many of the Mitotic changes that took place in telophase? | They are reversing for the two new cells |
| What happens to chromosomes in telophase? | chromosomes unwind for protein synthesis |
| What happens to the spindle, nucleolus, and nuclear membrane in telophase? | Spindle breaks down and nucleolus reappears, new nuclear envelope forms around each set of chromosomes; a new double membrane begins to form around the 2 new nuclei |
| Cytokinesis | Following telophase, the cell;s cytoplasm divides in a process celled Cytokinesis |
| Cytokinesis and Animal Cells | Plasma membrane pinches in along the equator |
| Cytokinesis and Plant Cells | A cell plate is laid down across the cell's equator; a cell membrane forms around each cell, a new cell wall form on each side of the cell plane until separation is complete. |
| How does the cervix keep sperm and bacteria out of the uterus? | it is locked shut with mucus |
| Where is the egg when it is fertilized by the sperm | Fallopian tube |
| do the fastest sperm always reach the egg first | no, they don't |
| what is a zona? | the egg is encased in a protein shell called the... |
| how do sperm break through the zona to get to the egg? | Proteins on the sperm must hook up and match the protein of the egg |
| how many chromosomes do sperm have? | 23 chromosomes |
| How many days after fertilization does the egg reach the uterus? | 5 days |
| What two things must the blastocyst do to survive? | Brake out of the zona and find a source of nourishment |
| What could attack the blastocyst in the uterus? What does the blastocyst do to protect itself? | The mother's immune system. produces chemicals to protect itself |
| Gastrolation | When a blastocyst becomes an embryo, the process is called |
| What happens once the embryo is formed | the cells multiply rapidly |
| How does the embroyonic cells transform themselves into different types of tissues? | By DNA |
| Are the chromosomes in every cell in your body the same or different | the same |
| What do the genes that are turned on do? | It tells the cell to construct a particular protein |
| What are colagen, keratin, crystalin, actin, myosin, and hemoglobin are all examples of? | proteins |
| How do cells turn certain genes depending on their? | location |
| If the DNA from one cell was stretched out, how many feet long would it be? | 6 feet long |
| How early can you see the sex of a fetus in an ultrasound? | 18 weeks |
| At 7 weeks what could gonads become? | testicles or ovaries |
| How do fingers form? What message is sent to the cells between each finger? | Cells in between fingers die. Form from the buds |
| A fetus is formed how many months after fertilization? | 2 months |
| Why sex? | Gene shuffling? |
| How many chromosomes do sperm, egg, zygot, and human adults have? | 23,23,46,46 |
| What are male gametes called? | sperm |
| Where are sperm made? | made in the testicles |
| Where are the testicles? | inside the scrotum |
| How many sperm can a mature man produce a day? | 30 million |
| What do sperm contain? | contains many mitochondria for locomotion (flagella) |
| What are female gametes called? | eggs |
| Where are eggs made? | In the ovaries |
| What is oogenisis? | egg formation |
| What does human embryology | Begins with the fertilization of an egg by a sperm |
| What is a fertilzed egg? | called a zygote |
| What does a zygote do? | it divides into two cells and then into four cells |
| What are embryos? | When a fertilized egg divides into two cells and then into four |
| What happens in early development? | embryo develops into a solid ball of 64 cells |
| What is a morula? | A solid ball of 64 cells that the embryo develops into |
| What is a blastula | the morula then hollows out to form this |
| What and when does a zygote become a fetus? | About 8 weeks after fertilization |
| What happens in the 2nd trimester? | The fetus becomes more complex and the organs begin to function |
| What happens in the 3rd trimester? | The fetus doubles in mass and completes its development |
| What happens after 40 weeks? | birth occurs :) |
| When does an embryo become male? | after six weeks, differences become apparent |
| the default sex of embryo is? | female |
| What chromosomes is a special gene activated in embryos | XY chromosomes |
| What does the special gene cause the release of? | testicular hormones (testosterone) |
| Why are ther lots of checkpoints during the cell cycle to ensure that...? | everything is working properly |
| What monitors the progression of each phase in the cell cycle? | enzymes |
| Why is accurate cell division and regulation of the cell cycle? | If there is a problem with the cell cycle and it does not work properly then you might not be able to heal and might have growng issues |
| What could happen if the cell cycle is not reulated? | You would have too many cells |
| Enzymes do what two things for the cell cycle? | they begin and drive the cell cycle; control the cycle through its phases |
| Mistakes iin the cell cycle occur if the cell does what? | fails to produce certain tumor suppressing enzymes; overproduces certain enzymes (oncogenes); produces other enzymes at the wrong time (proto-oncongenes) |
| Cancer | over 100 diseases; develops over time |
| What is the result of cancer? | result of uncontrolled cell division |
| What can cancer develop in | any cell of the body; why ther are many different types of cancer |
| tumor | mass of cancer cells; deprive normal cells of nutrients |
| benign | does not spread (not deadly) |
| metastic | does spread (can be deadly) |
| Metastasis | later stages of cancer development |
| Why does metastis occurs? | occurs if cancer cells ener the orculatory system and spread throughout the body |
| What do traveling cancer cells form? | form new tumors in different organs throughout the body |
| What causes cancer? | cancer is genetic as well as environmental |
| Cancer is a what process? | multi step |
| Why do tumors appear? | when they have grown to 10-100 billion cells |
| When does cancer typically occurs? | after a long time of repeated exposure and genetic mutation |
| Who are those most at risk? | Older ages; higher exposure to mutagens; compromised immune systems |
| What are the most common forms of cancer? | lung, colon, breast, skin, prostate |
| Dr. Jane Cooke Wright | Professor of surgery; head of the cancer chemotherapy department; associate dean at NY medical college; highest ranked african-american woman at a nationally recognized medical institution; first woman to be elected president of the New York Cancer Society |
