Unit 2: Ch 3, 5 Flashcards

Question

Cristae

Answer 1

* The inner membrane of mitochondrion

Answer 2

* May overlap with anaphase and telophase, but does not reach completion until just before the next interphase * _Animal cells_ * Forms between the two daughter nuclei * Separates the cytoplasm to create two daughter cells * _Plant cells_ * The rigid cell wall _does not permit cytokinesis_ by furrowing * Involves building new cell walls between the daughter cells

Answer 3

* The material inside the cell * 2 parts: * _Cytosol:_ the fluid part; mostly water * _Organelles:_ "little organs" inside the cell

Answer 4

* Forms the shape of a cell and the movement of its parts. Often compared with the bones and muscles of an animal * Non-membranous * Components * Microtubules * Intermediate filaments * Actin filaments

Answer 5

* Plants * Have a cell wall located outside the membrane that is made of cellulose * Have chloroplasts * Have a large vacuole to store material

Answer 6

* The number of chromosomes, where two of each type of chromosome are present, in a species * Humans have 46 diploids *(23 homologous pairs of chromosomes)* * The correct diploid number is necessary for the correct function of an organism * Abbreviated 2n

Answer 7

* DNA is a nucleic acid polymer with 2 conformations * Chromatin * Chromosome * DNA nucleotides * Adenine * Thymine * Cytosine * Guanine

Answer 8

* Invented in 1950s * Magnifies 500k * The illumination source is electrons * Very expensive ($1M) * Cannot view living specimens. This is because the specimen is placed in a vacuum chamber * Can view thick or thin specimens * 2 types * _Scanning electron microscope_: used to view surfaces (such as the surface of a cell) * _Transmission electron microscope_: used to see inside an object (such as inside a cell)

Answer 9

* Fertilization occurs * Cleavage begins * The morula is transformed into the blastocyst

Answer 10

* Embryo begins the process of implanting in the wall of the uterus * It is about the size of a period * The trophoblast begins to secrete the hormone human chorionic gonadotropin (HGP), which is the basis for the pregnancy test * Yolk sac/amniotic fluid forms * Gastrulation occurs

Answer 11

* Two important organ systems appear: * Nervous system * Heart

Answer 12

* Body stalk connects the tail end of the embryo with the chorion * The umbilical cord is fully formed * Limb buds appear

Answer 13

* The head achieves its normal relationship with the body as a neck region develops * All organ systems have been established

Answer 14

1. Cleavage 2. Morula 3. Blastula (blastocyst) 4. Gastrula 5. Neurula

Answer 15

* An interconnected system of membranous channels and sacs (flattened vesicles) that is physically continuous with the outer membrane of the nuclear envelope * 2 types: * _Rough ER_: Has ribosomes attached * _Smooth ER_: No ribosomes attached

Answer 16

* Chloroplasts use solar energy to synthesize carbs, which are broken down by the mitochondria to produce ATP molecules * When cells use ATP as an energy source, energy dissipates as heat * Nearly all organisms use the carbs produced by photosynthesizers as an energy source * Many organisms carry on cellular respiration

Answer 17

* Location of sperm maturation in an adult human male * Sperm storage

Answer 18

The two haploid daughter cells have the incorrect chromosome configuration. Each chromosome should be made of only one chromatid

Answer 19

Daughter cells have the correct chromosome configuration because each chromosome is made of only one chromatid.

Answer 20

* Sperm deposited at cervix * Sperm swim through the uterus to reach the oviduct * There are two oviducts, but oocyte is in one of them * Some sperm will find oocyte and squeeze through the _corona radiata_ * Sperm must bind to the _zona pellucida_ * _Acrosome_ reaction occurs * Sperm binds to _oocyte receptor_ * Membrane of sperm and egg cell _fuse_ * Nucleus of the sperm _enters the egg cell_ * Two nuclei fuse together, restoring the diploid chromosome number, and creating one _zygote_

Answer 21

1. Changes to the egg cell membrane 2. Zona pellucida detaches from the egg and lifts off the egg, physically pushing the other sperm away from the egg * Exception: * If two sperm fuse with the egg cell at the EXACT same time (polyspermy) * Results in zygote having too many chromosomes

Answer 22

* Follicles are cavities in the ovary * _Primary follicle:_ contains the primary oocyte; is the smallest follicle * _Secondary follicle_: contains the secondary oocyte; is bigger than primary because it fills with fluid * _Graafian follicle_: contains the secondary oocyte * The difference between secondary & Graafian follicle is just size * Graafian is larger

Answer 23

* Cells continue to perform normal processes, but no preparations are being made for cell division

Answer 24

* Cell cycle main checkpoint * Allows the cell to determine whether conditions are favorable to begin the cell cycle * Occurs before DNA replication * Organelles replicate * Some cells exit G₁ to enter G₀

Answer 25

* Checkpoint after DNA replication (S phase) * Cell cycle stops if the chromosomes are not going to be distributed accurately to the daughter cells * If DNA is damaged, this stage allows time for it to be repaired * Growth and final preparation for division

Answer 26

* Cell used for reproduction * _Oocyte:_ female gamete * _Spermatocyte_: male gamete

Answer 27

* 4th stage of embryonic development * Occurs ~ 7-10 days after fertilization * Occurs in uterus * Cells of the blastula rearrange * Rearrangement creates 3 regions of cells * Endoderm * Ectoderm * Mesoderm * Rearrangement "commits" the cells to form certain structures in the embryo (no longer capable of forming any cell type)

Answer 28

* Crossing over * Non-sister chromatids exchange segments of DNA * Independent assortment at the metaphase plate * More than 1 way in which chromosomes can line up at the metaphase plate and separate * Many different combinations of chromosomes in the gamete cells * For humans: 223 = over 8M different combinations in the gamete cells

Answer 29

* Consists of a stack of between 3 and 20 slightly curved sacs whose appearance can be compared to a stack of pancakes * Referred to as the shipping center of the cell because it collects, sorts, packages, and distributes materials such as proteins and lipids * Forms the lysosome

Answer 30

* Cell condition in which only one of each type of chromosome is present * In humans, only sperm and eggs have the haploid number of chromosomes

Answer 31

* Form during meiosis I * A set of 1 maternal and 1 paternal chromosome that pair up * They have the same genes in the same location where they provide points along each chromosome which enable a pair of chromosomes to align correctly with each other before separating during meiosis

Answer 32

Fourteen pairs = 28 chromosomes total. A gamete has half that number which would be _14_.

Answer 33

* Blastula migrates into the uterus, where it burrows into the endometrial lining and latches on (implementation) * Occurs ~ 7 days after fertilization * Stays in the lining until development is completed * Burrowing can produce slight bleeding which can be incorrectly interpreted as a menstrual cycle

Answer 34

* Inner cell mass * Cells on the inner cell mass are called _stem cells_ since they can form any cell in an organism * Form the organism

Answer 35

* The period of time between meiosis I and meiosis II during which _no DNA replication_ takes place * The daughter cells of meiosis I proceed directly into meiosis II

Answer 36

* Invented in 1600s * Magnifies 1000x * Illumination source is light * Features: * Can only view thin specimen * Can view dead or living specimens * Relatively inexpensive

Answer 37

* Membrane-bound vesicles produced by the Golgi apparatus * Contain hydrolytic digestive enzymes and act as the garbage disposals of the cellular factory

Answer 38

* Occurs in any life cycle that involves sexual reproduction * Produces gamete cells * 2 rounds of nuclear division of 1 mother cell forming 4 haploid daughter cells (reduces the chromosome number from 2n to n) * Daughter cells are genetically identical to the parent

Answer 39

* Produces haploid cells that are genetically _different_ than the original diploid parent cell * Important to the long-term survival of a species because it increases genetic variation within a population

Answer 40

* Undifferentiated embryonic tissue in the active growth regions of plants * Plant tissue that retains the ability to divide throughout its life

Answer 41

* 2nd phase of mitosis * Fully formed mitotic spindle * Spindle fibers attach to the centromere of each sister chromatid * Asters develop to anchor assembly within the cell * Chromosomes are aligned at the metaphase plate

Answer 42

* Helps maintain the shape of the cell and acts as tracks so that organelles can move * Organizing center is in the centrosome

Answer 43

* Membrane-bound organelle in which ATP molecules are produced during the process of cellular respiration * The "power plant" of the cell * Contains its own DNA * Involved in cellular differentiation, cell death, and the aging process

Answer 44

* Nuclear cell division * Occurs when tissues grow or when repair occurs * Cannot be used to create gamete cells * At the completion, each of the chromosomes in the daughter cells consists of a single chromatid * Stages * Prophase * Metaphase * Anaphase * Telophase

Answer 45

* _Density dependent inhibition_: Cells will stop dividing when they physically touch another cell * _Hormones_: Communication chemicals. Hormones are how cells and organs communicate with each other. Some hormones tell a cell to divide by mitosis. * Ex: growth and sex hormones * _Growth factors:_ Proteins secreted by a cell under specific circumstances. They tell the other cells immediately surrounding it to divide. * Ex: epidermal growth factor. It is secreted by injured cells to tell cells around it to divide so the injury can be healed. It is also naturally found in the saliva of animals and is why animals will lick their wounds. Doing so distributes the EGF to the cells

Answer 46

* Proto-oncogene * Encode proteins that promote the cell cycle and prevent apoptosis * Growth factor * Hormones that deliver a signal to the plasma membrane of target cells * Tumor suppressor gene * Encode proteins that slow the cell cycle

Answer 47

* Cells experience cell division at different times * Some don't divide after birth (ie nerve cells & muscle cells enter G₀) * Some lose the ability to do mitosis as they age (bones cells enter G₀) * Some constantly perform mitosis (skin and blood cells)

Answer 48

* Same phases occur in plant cells as in animal cells * Plant cells have a centrosome and spindle, but they do not have centrioles or asters that form during cell division

Answer 49

* 2nd stage in embryonic development * Occurs 4 days after fertilization * Occurs in the oviduct * Due to cleavage, a solid ball of cells are formed

Answer 50

* Stage 5 of embryonic development * Occurs ~ 1 month after fertilization * Occurs in uterus * Gastrula cells rearrange * Key formations: * Nervous system * Neural tube (neural tube becomes the spinal cord) * Notochord (vertebra) * Hollow regions: Gut & Coelom

Answer 51

* When chromosomes fail to separate properly during meiosis I or II * Creates gametes with an incorrect chromosome # * Results in chromosome disorders such as Down's syndrome * Occurs most often in oogenesis, but can also occur in spermatogenesis

Answer 52

* Double layer membrane surrounding the nucleus * Separates the nucleus * Continuous with the ER * Has nuclear pores to permit the bidirectional transport of proteins and ribosomal subunits

Answer 53

* Concentrated area of chromatin, RNA, and proteins * Ribosomal subunit formation

Answer 54

Watery material inside the nucleus, containing chromatin

Answer 55

* Membrane-bound organelle within a eukaryotic cell that contains chromosomes and controls the structure and function of the cell * Storage of genetic information * Synthesis of DNA and RNA * Structure * Nuclear envelope * Nucleoplasm * Nucleolus

Answer 56

* Cancer-causing gene formed by a mutation in a proto-oncogene * Codes for proteins that stimulate the cell cycle and inhibit apoptosis

Answer 57

* Upon completion of meiosis, the oocyte becomes an egg * Oocyte types: * _Primary oocyte_: diploid mother cell that begins meiosis * _Secondary oocyte_: haploid daughter cell formed at the end of meiosis I

Answer 58

* Following puberty and the initiation of the menstrual cycle, one primary oocyte begins to complete meiosis. It finishes the first meiotic division as two cells, each of which is haploid, although the chromosomes are still duplicating

Answer 59

Tube connecting ovary and uterus. Site of fertilization.

Answer 60

* Release of a secondary oocyte from Graafian follicle into the oviduct * Viable for 18-24 hours

Answer 61

* Membranous, enzyme-filled vesicle in which fatty acids and amino acids are metabolized to hydrogen peroxide that is broken down into harmless products * Contain an enzyme called catalase that breaks down H₂O₂ to water

Answer 62

Sunlight + CO₂ + H₂O → Glucose + O₂

Answer 63

* Regulates the entrance and exit of molecules into and out of the cytoplasm * Phospholipid bilayer with embedded proteins * 2 regions * _Intracellular region:_ inside the cell * _Extracellular region:_ outside the cell

Answer 64

* Nonfunctional product of oogenesis * Produced by the unequal division of cytoplasm in females during meiosis * In humans, 3 of the 4 cells produced by meiosis are polar bodies

Answer 65

* When more than one sperm enters an oocyte * Results in the zygote having too many chromosomes, and development would be abnormal

Answer 66

* _Embryonic_ * An embryo from implantation to 3 months of development * Creates the pattern formations for organs to form * _Fetal_ * 3 months from implantation to birth * Fetal development based on the pattern formation created to form the correct structure

Answer 67

* _Primary_: Consist of only one chromatid * _Secondary_: Duplicated and consist of two chromatids

Answer 68

* Phase of cell division that occurs between prophase and metaphase * Characterized by attachment of the spindle fibers to the kinetochores of each sister chromatid

Answer 69

* 1st phase of mitosis * Starts the process of nuclear division * Nuclear envelope begins to disintegrate * Spindle fibers begin to form * Chromatin condenses and the chromosomes are now visible

Answer 70

* Regulate import and export of material * Communication between cells * Cell identification * Type of cell * Species * Individual within the species

Answer 71

* Gene that promotes the cell cycle and prevents apoptosis * May become an oncogene through mutation * Likened to the gas pedal of a car because they cause cells to continue through the cell cycle

Answer 72

* Site of protein synthesis in a cell * Composed of proteins and ribosomal RNA * Smallest organelle in the cell. Can only be seen with the electron microscope * No membrane

Answer 73

* Studded with ribosomes on the side of the membrane that faces the cytoplasm * Modifies and processes newly made proteins * As proteins are synthesized on these ribosomes, they pass into the interior of the ER, where processing and modification begin * Proteins synthesized here are destined for the membrane of the cell or to be secreted from the cell

Answer 74

* DNA replication/duplication * At the beginning, each chromosome is composed of one chromatid * At the end, each chromosome consists of 2 sister chromatids that have identical DNA

Answer 75

* Receives almost all of the cytoplasm * If fertilized by a sperm, it completes meiosis II * Cytoplasm divides unequally * Forming an egg and a second polar body * The chromosomes of the egg and sperm nuclei then join to form the 2n zygote * If the secondary oocyte is not fertilized by a sperm, it disintegrates and passes out of the body with the menstrual flow

Answer 76

* One of two genetically identical chromosomal units that are the result of DNA replication and are attached to each other at the centromere

Answer 77

* Is continuous with rough ER but does not have attached ribosomes * Synthesizes the phospholipids found in cell membranes, as well as those that perform other functions * Stores calcium ions * Forms vesicles in which products are transported to the Golgi apparatus

Answer 78

Any non-gamete body cell

Answer 79

* 3 parts to a sperm: * _Head:_ Contains the haploid nucleus and is capped by a membrane-bound acrosome * _Midpiece:_ Contains hundreds of mitochondria to produce the energy necessary to swim * _Tail_: a flagella used for swimming * ~100M released at the cervix, less than 10% reach the oocyte * The binding of sperm is specific * Prevents gametes of opposite species from fertilizing * Some exceptions

Answer 80

* Production of sperm in males by the process of meiosis and maturation

Answer 81

It may be miscarried or develop a disorder. The zygote would have an extra chromosome.

Answer 82

* 4th phase of mitosis * Daughter chromosomes are at opposite sides of the cell * Cleavage furrow appears at the middle of the cell which will divide the cell in two * Many events in telophase are the "undoing" of prophase: spindle disappears, chromosomes de-condense to form chromatin, nucleus reforms, and centrosomes move next to the nucleus * Each daughter nucleus contains the same number and kinds of chromosomes as the original parental cell

Answer 83

* Site of spermatogenesis * Testes made of tubules are called seminiferous tubules

Answer 84

* At birth: all primary oocytes are present in the ovary and have begun meiosis I, but paused in prophase I * At puberty until menopause: once a month, one primary oocyte completes meiosis I * Forms secondary oocyte * Begins meiosis II but pauses in prophase II * If fertilization occurs: secondary oocyte completes meiosis II to form the gamete

Answer 85

* At puberty until death * Primary spermatocytes are constantly formed from cells called a spermatogonium * Primary spermatocytes constantly undergo meiosis I and II to produce spermatocytes (sperm cells) * Rate of 300k sperm per minute or 40M per day * Notes * Unlimited number of gamete cells * There are no pauses in meisosis. Once it is started, it immediately finishes

Answer 86

* Form embryonic structures that are not part of the organism (ie placenta and amniotic fluid) * Secretes HCG, which is detected by a urine pregnancy test

Answer 87

* Takes place in oogenesis * Each time cytokinesis takes place, there is an unequal division of the cytoplasm * The large cell is the primary or secondary oocyte * The small cell is the _polar body_ * The last polar body at the end of oogenesis is non-function (is not likely to be fertilized, and if it were, it would not develop into a viable zygote)

Answer 88

Site of embryonic and fetal development

Answer 89

* Membranous sacs of various sizes * Storage of substances

Answer 90

Storage location for mature sperm before they pass into the ejaculatory duct

Answer 91

Produce gamete cells

Answer 92

Because the sister chromatids within the two daughter cells separate and form four new haploid gametes.

Answer 93

Without mitosis, cancer results

Answer 94

* A diploid cell formed by the union of two gametes; the product of fertilization

Unit 2: Ch 3, 5 Flashcards

(125 cards)