Lab Exam 1
Mitosis is traditionally divided into 5 stages:
1. prophase 2. prometaphase 3. metaphase 4. anaphase 5. telophase
how many chromatids does it have during metaphase
16
define centrosomes
2 microtubule organizing centers
human development requires nine months of development . human embryonic development encompasses _________.
2 months embryonic 7
Question 2a Lab 2 How many chromatids are involved in crossing over of a homologous pair of chromosomes?
4 chromatids
question 2 b lab 2 How many different combinations of these alleles would be possible?
4 combinations
question 3a page 243 lab 2 if a nucleus has eight chromosomes when it begins meiosis how many chromosomes does it have after telophase 1 and 2?
4 in telophase 1 4 in telophase 2
how many chromosomes have after mitosis is complete
8
chorion
Outermost layer of the two membranes surrounding the embryo; it forms the fetal part of the placenta.
describe zygote formation
a single sperm fertilizes an egg and the result is a zygote, the first cell of the new individual
umbilical cord
a tube containing the blood vessels connecting the fetus and placenta
48 hour check embryo - margin (edge) of the amnion
above vitelline arteries
define aster
arrangement of microtubules radiating from centriole
define kinetochore microtubules
attatch to each chromosomes kinetochore
define polar microtubules
axis of proteinaceous microtubules
To produce a new genetic combination each chromosomes initially pairs along its length with its homologous to form a ______. This pairing of homologous chromosomes is called _____, and the four chromatids exchange homologous segments of genetic materials called ____. This exchange of genetic material among chromatids is called ___ and produces new genetic combinations
bivalent, synapsis, alleles, crossing-over
48 hour check embryo - somites
blocks of developing muscles
define mitotic spindle
bridge of microtubules
describe early gastrula stage
certain cells push into blastocoel at blastopore
Question 5b page 239 lab 1 How does cytokinesis differ in plant versus animal cells?
cleavage furrow forms in animal cells but a cell plate forms across the equation of plant cell
in animal cells , cytokinesis include formation of ______ that begins on the periphery of the cell, pinches inward, and eventually divides the cytoplasm into two cells . In plants, cytokinesis includes formation of a partition called ___ perpendicular to the axis of the spindle apparatus.
cleavage furrow, cell plate
define kinetochore
complex of proteins that binds to centromere
yolk sac in mammal
contains blood vessels , first site of blood formation
yolk sac in chicks
contains yolk, food for developing embryo
48 hour check embryo- heart
contracting and circulating blood
define centrioles
cylinders of microtubules
48 hour check embryo - eye
developing lens
chromosomes in typical, eukaryotic nuclei occur in pairs; that is, the nuclei are ___ (2n). The two chromosomes of a par are called ____, and each homologous pair has the same sites, or loci, for the same genes, although homologous may carry different alleles at homologous loci. A nucleus such as that in a gamete, with only one chromosome of each homologous pair is ____.
diploid, homologous chromosome, haploid
fig 15.1 which shows meiosis produces ____ and ______ in animal, both of which are haploid. Fushion of an egg and sperm during fertilization produces a ____, which is diploid.
eggs, sperm, zygote
48 hour check embryo - caudal fold
embryo completely enveloped when head fold and caudal fold meet the margin
Primary germ layer - ectoderm . Pig adult structure-
epidermis of skin.: epithelial lining of oral cavity and rectum; nervous system
primary germ layer - endoderm pig adult structure -
epithelial lining of digestive , respiratory tract; associated glands of systems
48 hour check embryo - vitelline arteries and veins
extend over yolk . carry nutrients from yolk sac to the embryo
allantois in mammal
extends into umbilical cord
yolk sac
first embryonic membrane to appear
amnion in chick
forms amniotic cavity , envelopes embryo, contains amniotic fluid that cushions and protects
amnion in mammals
forms amniotic cavity , envelopes embryo, contains amniotic fluid that cushions and protects
amnion
forms amniotic cavity which envelopes embryo
chorion in chicks
functions in gas exchange
meiosis occurs in all sexually reproducing eukaryotes and produces haploid nuclei. _____ are reproductive cells with haploid nuclei resulting from meiosis and the formation of gametes is called _____. Meiosis is the primary element of gametogenesis and animals. Male gametes of mammals are different from female gametes. Gametogenesis includes _____ the formation of sperm cells and ____ the formation of egg cells
gametes, gametogenisis, spermatogenisis, oogenesis
describe late gastrula stage
gastrulation not complete until 3 layers of cells.
allantois
involved in early fluid exchange between the embryo and the yolk sac
spermatogenesis occurs in _____, made of tightly coiled tubes called ____.
male testes, seminiferous tubules
question 3b page 243 lab 2 what are the major differences between the events of meiosis and mitosis?
meiosis involves 2 cell divisions . mitosis is 1 cell division.
Question 5a page 239 lab 1 What region of a root has the most mitotic activity?
meristem
the early development of animals is quite similar , regardless of species. The fertilized egg or zygote undergoes too excessive divisions by cleavage forming a mulberry shaped ball of cells called a ______.
morula blastula blastocoel ectoderm endoderm mesoderm gastrula yolk germ layers
describe blastular formation
morula becomes blastula, hollow ball of cells
during nervous system development in the frog, two folds of ectoderm grow upward. The flat layer of ectoderm between them is the ____.
neural plate neural tube notochord vertebrae nerve cord brain
As soon as all 3 embryonic tissue layers are established the organ level development begins. The first organs to develop are the digestive tract, ______, and heart
neural tube / brain
chorion in mammals
outer layer surrounds inner mass at blastocyte stage becomes chorion
extraembryonic membranes
outside the embryo , they are "extra"
oogenesis occurs in ____ of females. Cells of the ovary that produce female gamete are called ____.
ovaries , oocytes, oogenia, primary oocyte prophase 1 follicular cells follicles ovulation graafian follicle haploid set
the extraembryonic membranes take their name from the observation that they are not part of embryo proper.
placenta capillaries umbilical cord allantois yolk sac
Placenta
provides nutrition and oxygen to embryo
48 hour check embryo - brain
several distinct regions
Primary germ layer - mesoderm Pig adult structure-
skeleton; muscular system; dermis of skin; cardiovascular, urinary, reproductive, outer layer digestive, respiratory
packed against the inner walls of the tubules are diploid cells called _______, which constantly replicate mitotically during the life of male. Some of the daughter cells move inwards toward the lumen of the tubule and begin mitosis. These cells are called _____. Meiosis 1 of a primary spermatocyte produces 2 ______, each with a haploid set of double stranded chromosomes. Meiosis 2 separated the strands of each chromosome and produces 2 haploid cells called ____. Spermatids mature and differentiate into _____ cells as they move along the length of the tubule.
spermatogonia, primary spermocytes secondary spermocytes spermatids sperm
48 hour check embryo - shape of embryo
started to bend, head is now almost touching the heart
allantois in chicks
storage area for metabolic waste
Question 5d page 239 lab 1 What is a cell plate? What state of mitosis does it form?
structure found inside the dividing of plant cells during telophase
Question 5c page 239 lab 1 Why is pinching of the cytoplasm inadequate for cytokinesis in plants?
the cell wall will stay intact
describe morula formation
zygote divides into a number of smaller cells until there is a cluster of 16 to 32 cells
