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53 Cards in this Set
- Front
- Back
- 3rd side (hint)
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Define genetics |
The study of heredity and variation of living organisms and how genetic information is passed from one generation to the next |
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List the three statements of "cell theory" |
-all living things are composed of one or more cells -cells are the smallest units of living organisms -new cells come only from pre-existing cells by cell division |
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What is a somatic cell? |
A plant or animal cell that forms the body of the organism. This excludes reproductive cells |
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What are the functions or purposes of cell division? |
-growth of the organism -repair of damaged tissue or organs -maintenance to replace dying or dead cells |
There are 3 |
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List the stages of the somatic cell cycle |
-Interphase -mitosis -cytokinesis
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3 parts |
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Explain interphase |
the cell grows into a mature, functioning cell, copies its DNA, and prepares for division. G1 (growth 1): major period of growth for the cell. Synthesizes many new molecules. S (synthesis): cellular DNA is replicated which, at this stage, exists as uncondensed fibres called chromatin. G2: synthesizes more molecules prior to mitosis and cell division. |
G1, S, G2 |
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Describe prophase of mitosis |
1. The cells chromatin condenses into chromosomes. 2. the replicated DNA exists as sister chromatids attached by the centromere. 3. The nuclear membrane breaks down and the nucleolus disappears. 4. Spindle fibres form from the centrosomes as they move to opposite poles of the cell. |
Spindle apparatus formation |
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What does the spindle apparatus consist of and when is it formed? Also, what is its purpose? |
The spindle apparatus consists of spindle fibres and the centrosomes from which the fibres form. The apparatus is formed during prophase of mitosis or prophase 1 of meiosis. This apparatus serves to organize the chromosomes throughout mitosis or meiosis. |
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Describe metaphase of mitosis |
1. The spindle fibres guide the chromosomes to the equator of the cell 2. The fibres attach to the centromere of each chromosome Note: the sister chromatids are considered chromosomes so long as they remain attached. |
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Describe anaphase of mitosis |
1. Each centromere splits apart 2. The spindle fibres shorten, pulling the chromosomes to opposite poles of the cell |
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Explain telophase of mitosis |
1. The chromosomes begin to unwind into strands of chromatin 2. The spindle fibres break down 3. The nucleus membrane forms around the new set of chromosomes 4. Nucleolus forms inside each new nucleus |
Going back to normal |
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Explain cytokinesis as well as how it differs in plant and animal cells |
The division of the cytoplasm, creating two new daughter cells Animal: 1. An indentation forms in the cell membrane along the equator 2. Microfilaments constrict the cytoplasm, pinching it into two new cells Plant: 1. A cell plate forms between the two daughter nuclei |
Separation |
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What is a double helix? |
Made up of two long strands of DNA that form a spiral shape |
Think Spider-Man when spider causes genetic change |
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What are the individual units of each strand of DNA called? |
Nucleotides |
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What are nucleotides composed of? |
A phosphate group, a sugar group and a base (thymine and adanine or guanine and cytosine) |
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What is a complimentary base pair? |
The A-T and C-G pairs formed between the bases of a nucleotide |
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What is a genetic mutation? |
A change in the nucleotide sequence of the DNA |
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What is a genome? |
The complete DNA sequence |
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How many chromosomes do human diploid cells have? |
46 chromosomes or 23 pairs of homologous chromosomes |
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What are autosomes |
The non sex chromosomes (1-22) |
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Chromosomes are paired based one what? |
Sharing similar characteristics... -lengths -centromere location -banding pattern |
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Define homologous chromosome |
A chromosome that contains the same sequence of genes as an other chromosome. They contain genes for the same trait at the same location though they may be in different forms (alleles) |
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Define gene |
Part of the chromosome that governs the expression of a trait and is passed on to offspring. It has a specific DNA sequence. |
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Define allele |
A different form of the same gene |
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Define karyotype |
a photograph of pairs of homologous chromosomes in a cell |
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Define gamete |
A male or female reproductive cell. It is haploid |
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Define zygote |
A cell formed by the fusion of two gametes |
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Define fertilization |
The joining of male and female haploid gametes |
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Which is the gamete produced by the male and which is produced by the female? |
Males produce sperm cells while females produce primary oocytes (in the book it says ovum but this may be wrong) |
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Define haploid |
(Single) a cell that contains half the number of chromosomes as the parent cell |
Means single in Greek |
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Define diploid |
A cell that contains pairs of homologous chromosomes |
Means double in Greek |
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Describe meiosis |
There are two cycles of meiosis which each have 4 phases: prophase, metaphase, anaphase and telophase. |
Just brief description of it (not details of each part) |
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Describe prophase 1 |
-the homologous chromosomes line up (synapsis) and are held tightly together -while they are lined up, segments of the chromosomes may be exchanged -the centrosomes move apart to opposite poles and the spindle apparatus forms |
Synapsis and spindle apparatus |
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Describe metaphase 1 |
-the homologous chromosomes line up at the equator of the cell and the spindle apparatus attaches to the centromeres |
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Describe anaphase 1 |
-the homologous chromosomes separate and move to opposite poles -the centromeres do not split and the sister chromatids remain together -the chromosome number is reduced from diploid to haploid |
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Describe telophase 1 |
-the homologous chromosomes uncoil and the spindle fibres disappear -cytokinesis takes place and the nuclear membrane forms around each group of homologous chromosomes. two haploid cells form. |
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What is the difference between meiosis 2 and mitosis? |
They are the same except for the fact that the cell which undergoes division in meiosis 2 is haploid as opposed to diploid in mitosis |
Haploid vs diploid |
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Describe spermatogenesis |
-a form of meiosis preformed by the male reproductive cell -takes place in the testes of most male animals -begins with diploid cells called spermatogonium (reproduces via mitosis) -produces 4 sperm cells |
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Describe the sperm cell |
-the nucleus and certain molecules are organized into the head region -the midsection holds many mitochondria as a source of energy -at the end of the sperm cell, opposite the head, is a flagellum used for locomotion |
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Describe oogenesis |
-takes place in the ovaries of most females -begins with oogonium which reproduces through mitosis during first 7 months of development -the amount of primary oocytes produced during oogonium mitosis is all that will ever be produced -the primary oocytes begin meiosis but stop at prophase 1 -each month, one cell finishes meiosis and leaves the ovaries -when the primary oocyte undergoes cytokinesis, only one of the two daughter cells receives the majority of the cytoplasm -the cell that receives little cytoplasm is called a polar body and degenerates |
Oogonium, primary oocyte, polar body, meiosis and mitosis |
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What is independent assortment? |
-takes place during metaphase 1 -homologous chromosomes (one of maternal origin and The other of paternal origin) are split up and sent to opposite poles of the cell -the orientation of the two cells in the homologous pair is independent of the orientation of the other pairs
*the number of genetically distinct gametes that can be produced from a diploid cell is 2^n where n=the number of pairs* |
Pick a partner and split into two teams |
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Describe crossing over |
-occurs during prophase 1 -non-sister chromatids of homologous chromosomes may exchange pieces of chromosome -may occur at several points along non-sister chromatids |
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Could one chromosome contain genes of both maternal and paternal origin? |
Yes, as a result of crossing over. If one chromosome trades a section with a homologous chromosome, there will be a melange of paternal and maternal genes |
Crossing over |
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What is artificial insemination? |
Sperm are collected and concentrated before being introduced into the females reproductive system |
Concentrating sperm |
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What is an embryo transfer? |
The process by which an egg that has been artificially fertilized is transferred a recipient female's uterus |
Artificially fertilized egg. Transfer. |
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Explain the process of gene cloning |
1. Isolate the segment of DNA to clone and choose a vector for cloning 2. Insert the chromosomal DNA into the vector 3. Treat foreign cells so that they take in the recombinant DNA |
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Define therapeutic cloning |
The process of replacing an egg cell's nucleus with the nucleus from a somatic donor cell to produce a cell line of genetically identical cells. These cells are used to treat various diseases |
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Define reproductive cloning |
The process of producing genetically identical organisms |
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What are the two types of error during meiosis? |
Changes in chromosome structure and changes in chromosome number |
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What are the four types of changes in chromosome structure? |
Deletion: a piece of chromosome is deleted Duplication: a section of chromosome appears multiple times in a row Inversion: a section of chromosome is inverted Translocation: a segment of one chromosome becomes a attached to an other chromosome |
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Define non-disjunction |
The failure of homologous chromosome pairs or sister chromatids to separate during meiosis. May occur in anaphase 1 or 2 |
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What is monosomy? |
The loss of a chromosome due to non-disjunction |
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What is trisomy? |
The gaining of a chromosome due to non-disjunction |
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