Unit 2 Flashcards
heredity (p. 138)
the passing of traits from parents to offspring
genetics (p. 138)
variation of inherited characteristics
deoxyribonucleic acid (DNA) (p. 138)
carries genetic information in cells
gene (p. 138)
DNA molecule that codes for a particular trait; found on a chromosome
locus (p. 138
the location of a gene on a chromosome
polyploid (p. 139)
having more than two sets of chromosomes
asexual reproduction (p. 139)
the production of offspring from a single parent; the genetic makeup of the offspring is identical to that of the parent
sexual reproduction (p. 140)
the production of offspring from the fusion of two sex cells (usually from two different parents); the genetic makeup of the offspring is different from that of either parent
fragmentation (p. 143)
a method of asexual reproduction in which body fragment of the parent organism develops into a mature individual
mitosis (p. 143)
eukaryotic cell divides the genetic material in its nucleus into two new identical nuclei
interphase (p. 143)
when the genetic material (in the form of chromatin) is duplicated
chromatin (p. 143)
the tangled strands of DNA and protein within a eukaryotic nucleus
sister chromatid (p. 143)
the identical copy of a single chromosome that remains attached to the original chromosome at the centromere
cytokinesis (p. 145)
eukaryotic cell divides its cytoplasm into two new daughter cells
cloning (p. 146)
the process of producing one individual that is genetically identical to another, using a single cell or tissue
biotechnology (p. 146)
the use and modification of organisms for applications in engineering, industry, and medicine
genetically modified organism (p. 148)
an organism in which the genetic material has been altered using genetic engineering techniques
gamete (p. 152)
a sex cell
fertilization (p. 152)
the formation of a zygote by the joining together to two gametes
zygote (p. 152)
a cell produced by the fusion of two gametes
ova (p. 152)
female sex cells (egg cells)
meiosis (p. 153)
a two-stage cell divisionin which the resulting daughter cells have half the number of chromosomes as the parent cell; results in the formation of gametes or spores
homologous chromosomes (p. 153)
matching pairs of chromosomes, similar in size and carrying information for the same genes.
tetrad (p. 154)
a pair of homologous chromosomes, each with two sister chromatids
synapsis (p. 154)
the physical pairing up of homologous chromosomes during prophase I of meiosis
crossing over (p. 154)
the exchange of chromosome segments between homologous pairs during synapsis
gametogenesis (p. 157)
the production of gametes (sex cells) in animals
spermatogenesis (p. 157)
the production of mature sperm cells
oogenesis (p. 157)
the production of mature egg cells
karyotype (p. 158)
the chromosomes of an individual that have been sorted and arranged according to size and type
sex chromosomes (p. 158)
chromosomes that differ in males and females of the same species; the combination of sex chromosomes determines the sex of the offspring
autosomes (p. 159)
non-sex chromosomes
non-disjunction (p. 161)
the failure of homologous chromosomes to move to opposite poles of the cell during meiosis; results in an abnormal number of chromosomes in the daughter cells
trisomy (p. 161)
a chromosomal abnormality in which there are three homologous chromosomes in place of a homologous pair
monosomy (p. 161)
a chromosomal abnormality in which there is a single chromosome in place of a homologous pair
Down syndrome (p. 162)
a chromosomal abnormality in which an individual has three copies of chromosome number 21; also referred to as trisomy 21
prenatal testing (p. 163)
testing for a genetic order that occurs prior to birth
maternal inheritance (p. 167)
a type of inheritance in which a zygote formed from
two gametes inherits cytoplasmic DNA from only the female gamete
paternal inheritance (p. 168)
a type of inheritance in which a zygote formed from two gametes inherits cytoplasmic DNA from only the male gamete
horizontal gene transfer (p. 170)
the transfer of genetic information from one species into a different species
Cell Division Patterns (Somatic Cells / Body Cells)
interphase → mitosis karyokinesis → cytokinesis …. REPEAT (start with 46 end with 46)
Cell Division Patterns (Reproductive Cells / Germ Cells)
interphase → meiosis I → cytokinesis I → meiosis II → cytokinesis II (start with 46 end with 23)
Interphase
● chromosomes/DNA replicate, condense
(i.e. DNA wraps tightly around histone proteins)
Mitosis (PMAT)
● occurs in all somatic / body cells
● produces 2 genetically identical diploid nuclei
Cytokinesis
division of cytoplasm and organelles
Prophase
● asters (centriole & spindle fibre) move to the poles- forming the mitotic spindle
● nuclear membrane dissolves
● chromosomes shorten and thicken
Metaphase (Karyotype Stage)
● sister chromatids align in the middle
● spindle fibres from opposite poles attach to each sister chromatid at the kinetochore
Anaphase
● sister chromatids separate → now called chromosomes
●sister chromatids pulled to opposite poles
Telophase
● nuclear membrane appears around each new chromosome set creating two identical nuclei
●NM reappears
●spindles disappear
● cell membrane pinches in at cleavage furrow
● chromosomes “loosen” again becoming chromatin
What are 2 types of natural clones/copies?
● single cell bacteria
● identical twins (kind of)
What are 2 types of genetically designed clones/copies?
○ i.e. plants that make insulin
○ i.e. animals that make spider silk
Gene Cloning
■ plasmids with gene inserts placed into bacteria and yeast cells (factories!)
■ proteins made en masse by all the bacteria / yeast with the inserted gene
■ drugs / proteins made for human use
● Insulin is produced by bacteria & yeast (drug for diabetics)
● Insulin can produced by safflower plant seeds that have the insulin gene inserted into their genome (they are like factories)
Therapeutic Cloning
■ enucleated egg cell + somatic nucleus of organism you LOVE → grow tissue in a petri dish
■ use for transplant and / or drug tests
● expts to understand disease & test new drugs
Reproductive Cloning
■ enucleated egg cell + somatic nucleus of organism you LOVE → insert embryo in a uterus
■ grow a “full grown” clone! (sheep/Dolly, cow, goat, etc.)
○ make clones
○ make $$
What are some ethical issues with cloning?
● An increase in abortions and miscarriages.
● Deformed embryos and clones.
● Parenting a clone.
● Clones becoming self-sufficient.
● Unknown personality of the clone.
● Rights for the clone.
● Pet cloning vs. unwanted animals & exploitation of grief
Sexual Reproduction
● sexual reproduction unites two haploid (n) gametes → generating genetic diveristy
● a gonochoric species has a male organism and female organism that produce gametes
● gametes can unite via internal fertilization or external fertilization
Gametogenesis
● haploid gametes have one of each homologue
● haploid gametes therefore carry one copy of every gene (gene = allele + allele)
● fertilization creates diploid zygotes with ….
○ 2 copies of every gene (one on each homologue)
Interphase
●DNA replication
●chromosomes become sister chromatids