Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
195 Cards in this Set
- Front
- Back
|
The process by which a cell doubles its organelles and cytoplasm, replicates its DNA, and divides in two
|
cell division
|
|
|
For unicellular organisms, cell division is a means of...
|
reproduction
|
|
|
For multicellular organisms, cell division is a means of...
|
growth, development, and replacement of worn out cells
|
|
|
The division and distribution of the cell's DNA into two daughter cells such that each cell receives a complete copy of the original genome
|
mitosis
|
|
|
Nuclear division is also known as...
|
karyokinesis
|
|
|
Cell division is also known as...
|
cytokinesis
|
|
|
A period of growth and replication of genetic material prior to the initiation of mitosis is called...
|
interphase
|
|
|
A cell normally spends ___ of its life in interphase
|
90%
|
|
|
After replication the chromosomes consist of two...
|
sister chromatids
|
|
|
Sister chromatids are held together at a central region called the...
|
centromere
|
|
|
During interphase, _____ are not visible
|
individual chromosomes
|
|
|
When DNA is uncoiled it is called...
|
chromatin
|
|
|
The chromosomes condense, the centrioles separate and move towards opposite poles of the cell, the spindle apparatus forms between them and the nuclear membrane dissolves during...
|
prophase
|
|
|
Prophase consists of...
|
the chromosomes condensing and the spindles forming
|
|
|
The centriole pairs are at opposite poles of the cell, the fibers of the spindle apparatus attach to each chromatid at the centromere and the chromosomes align at the center of the cell during...
|
metaphase
|
|
|
Metaphase consists of...
|
the chromosomes aligning at the equator
|
|
|
The centromeres split so that each chromatid has its own distinct centromere, thus allowing sister chromatids to separate and be pulled toward opposite poles of the cell by the shortening of spindle fibers in...
|
anaphase
|
|
|
Spindle fibers are composed of...
|
microtubules
|
|
|
Anaphase consists of...
|
sister chromatids separating
|
|
|
The spindle apparatus disappears, the nuclear membrane forms around each set of new chromosomes (2n), the chromosomes uncoil in..
|
telophase
|
|
|
Telophase consists of...
|
new nuclear membranes forming
|
|
|
The cytoplasm divides into two daughter cells, each with complete nucleus and its own set of organelles during...
|
cytokinesis
|
|
|
In animal cells, cytokinesis occurs through a...
|
cleavage furrow
|
|
|
In mitosis, each daughter cell is...
|
2N or diploid
|
|
|
The stages of mitosis are...
|
1. Interphase
2. Prophase 3. Metaphase 4. Anaphase 5. Telophase 6. Cytokinesis |
|
|
Plant cells do not have...
|
centrioles
|
|
|
In plant cells, the spindle apparatus is synthesized by...
|
microtubule organizing centers that are not visible
|
|
|
Cytokinesis in animal cells takes place through a...
|
cell plate
|
|
|
An expanding partition that grows outward from the interior cell until it reaches the cell membrane
|
cell plate
|
|
|
Plant cells do not form a cleavage furrow because...
|
they are too rigid
|
|
|
The process by which sex cells are produced
|
meiosis
|
|
|
Meiosis produces cells that are...
|
haploid (1N)
|
|
|
Meisosis involves two divisions of ______ resulting in ___ haploid cells called ______
|
primary sex cells; four; gametes
|
|
|
The first division of meiosis produces...
|
two intermediate daughter cells with N chromosomes with sister chromatids
|
|
|
The chromatin condenses into chromosomes, the spindle apparatus forms, and the nucleoli and nuclear membrane disappear during...
|
prophase I
|
|
|
In prophase I, homologous chromosomes come together and intertwine in a process called...
|
synapsis
|
|
|
Chromosomes that code for the same traits, one inherited from each parent
|
homologous chromsomes
|
|
|
Each synaptic pair of homologous chromosomes contains...
|
four chromatids, and is called a tetrad
|
|
|
Crossing over occurs during...
|
prophase I of meiosis
|
|
|
Crossing over occurs between...
|
homologous chromosomes, not sister chromatids
|
|
|
Recombination results in...
|
increased genetic diversity
|
|
|
In metaphase I...
|
homologous pairs align at the equatorial plane, and each pair attaches to a separate spindle fiber by its kinetochore
|
|
|
In anaphase I...
|
the homologous pairs are separated and pulled to opposite poles of the cell
|
|
|
Disjunction occurs during...
|
anaphase I
|
|
|
Each chromosome of paternal origin separates from its homologue of maternal origin and either chromosome can end up in either daughter cell, a process known as...
|
disjunction
|
|
|
A nuclear membrane forms around each new nucleus, at which point each chromosome still consists of sister chromatids joined at centromere during...
|
telophase I
|
|
|
The second meiotic division is not preceded by...
|
chromosomal replication
|
|
|
In human females, only one of the four daughter cells is...
|
a functional gamete
|
|
|
Mitosis or meiosis?
2N->2N |
mitosis
|
|
|
Mitosis or meiosis?
2N->1N |
meiosis
|
|
|
Mitosis or meiosis?
Homologous chromosomes do not pair up |
mitosis
|
|
|
Mitosis or meiosis?
Homologous chromosomes pair up at metaphase plate |
meiosis
|
|
|
Mitosis or meiosis?
No crossing over |
mitosis
|
|
|
Mitosis or meiosis?
Crossing over can occur |
meiosis
|
|
|
The production of offspring without fertilization
|
asexual reproduction
|
|
|
In asexual reproduction, offspring are genetically identical to parents except for...
|
random mutations
|
|
|
The types of asexual reproduction are...
|
1. fission
2. budding 3. regeneration 4. parthenogenesis |
|
|
Prokaryotes reproduce...
|
asexually
|
|
|
All plants reproduce...
|
asexually in some way
|
|
|
A simple form of asexual reproduction seen in prokaryotic organisms
|
binary fission
|
|
|
The DNA replicates and a new plasma membrane and cell wall grow inward along the midline of the cell, dividing it into two equally-sized cells with equal amounts of cytoplasm, each containing a duplicate of the parent chromosome in...
|
binary fission
|
|
|
Fission occurs in one-celled organisms such as...
|
amoebae, paramecia, algae, and bacteria
|
|
|
The replication of the nucleus followed by unequal cytokinesis
|
budding
|
|
|
The cell membrane pinches inward to form a new cell that is smaller in size but genetically identical to the parent cell, and which subsequently grows to adult size in...
|
budding
|
|
|
Budding occurs in...
|
hydra and yeast
|
|
|
The regrowth of a lost or injured body part
|
regeneration
|
|
|
Replacement of cells in regeneration occurs by...
|
mitosis
|
|
|
Regeneration occurs in...
|
salamanders, starfish, hydra, tadpoles
|
|
|
The development of an unfertilized egg into an adult organism
|
parthenogenesis
|
|
|
Parthenogenesis occurs in...
|
bees and ants
|
|
|
In most species of bees and ants, males develop from...
|
unfertilized eggs
|
|
|
A diploid generation is succeeded by a haploid generation in...
|
alternation of generations
|
|
|
The sporophyte generation is...
|
diploid
|
|
|
The gametophyte generation is...
|
haploid
|
|
|
The diploid _____ generation produces _____ which develop into haploid _____ generation
|
sporophyte; haploid spores; gametophyte
|
|
|
Specialized cells with hard coverings that prevent loss of water
|
spores
|
|
|
Undifferentiated tissues in plants that provide a source of cells that can develop into an adult plant
|
meristems
|
|
|
Vegetative propagation is advantageous because...
|
it introduces no genetic variation and is a rapid form of reproduction
|
|
|
Vegetative propagation can occur naturally through...
|
1. bulbs
2. tubers 3. runners 4. rhizomes |
|
|
Bulbs can split to form..
|
several bulbs
|
|
|
Bulbs occur in...
|
tulips and daffodils
|
|
|
Underground stems with buds that can grow into adult plants
|
tubers
|
|
|
Tubers are found in...
|
potatoes
|
|
|
Stems running above and along the ground, extending from the main stem and can produce new roots and upright stems
|
runners
|
|
|
Runners are seen in...
|
strawberries and lawn grasses
|
|
|
Woody, underground stems that can develop new upright stems
|
rhizomes
|
|
|
Rhizomes are also called...
|
stolons
|
|
|
Rhizomes are seen in...
|
ferns and iris plants
|
|
|
A cut piece of stem can develop new roots in water or moist ground, as seen in...
|
geraniums and willows
|
|
|
Synthetic plant hormones can be used to accelerate root formation
|
auxins
|
|
|
Stems can take root when bent to the ground and covered with soil
|
layering
|
|
|
Layering can be seen in...
|
blackberries and raspberries
|
|
|
The stem of one plant, called the _____, can be attached to the rooted stem of another closely related plant called the ______, but the ____ tissue of both stems must be in contact
|
scion; stock; cambium
|
|
|
Specialized sex organs that produce gametes
|
gonads
|
|
|
The male gonads that produce sperm in the seminiferous tubules
|
testes
|
|
|
The female gonads
|
ovaries
|
|
|
Ovaries produce...
|
oocytes
|
|
|
Species with both functional female and male gonads
|
hermaphrodites
|
|
|
Some hermaphroditic species are...
|
hydra and earthworm
|
|
|
Sperm production
|
spermatogenesis
|
|
|
Spermatogenesis occurs in the...
|
seminiferous tubules
|
|
|
In spermatogenesis, _____ cells called ______ undergo ____ to produce ______
|
1. diploid
2. spermatogonia 3. meiosis 4. four haploid sperm |
|
|
The head of sperm consists almost entirely of...
|
the nucleus which contains the paternal genome
|
|
|
The tail of sperm...
|
is a flagellum that propels it
|
|
|
The neck and body of sperm contains...
|
mitochondria to provide energy to move
|
|
|
In oogenesis, one _____ primary female sex cell undergoes ____ in the ____ to produce a _______
|
1. diploid
2. meiosis 3. ovaries 4. single mature egg |
|
|
Each meiotic division of eggs produces a...
|
polar body
|
|
|
A small cell that contains little more than the nucleus
|
polar body
|
|
|
The union of egg and sperm nuclei to form a zygote with a diploid number of chromosomes
|
fertilization
|
|
|
External fertilization occurs in...
|
vertebrates that reproduce in water (fish and amphibians)
|
|
|
External fertilization is less efficient because...
|
sperm is deposited in the vicinity of eggs, so there is no direct passage
|
|
|
Internal fertilization occurs in...
|
terrestrial vertebrates
|
|
|
The testes are located in an external pouch called...
|
the scrotum
|
|
|
The scrotum maintains testes temperature 2-4 degrees Celsius lower than body temperature, which is...
|
a condition essential for sperm survival
|
|
|
The order in which sperm passes is...
|
1. seminiferous tubules
2. epididymis 3. vas deferens 4. ejaculatory duct 5. urethra 6. penis |
|
|
The urethra in males...
|
passes through the penis and opens to the outside at its tip
|
|
|
In males, the urethra is a common passageway for both...
|
reproductive and excretory systems
|
|
|
The testes also produce...
|
testosterone
|
|
|
Testosterone regulates...
|
secondary male sex characteristics
|
|
|
Secondary male sex characteristics include...
|
facial and pubic hair and voice changes
|
|
|
The ovaries are found in the...
|
abdominal cavity, below the digestive system
|
|
|
A multi-layered sac of cells that contains, nourishes, and protects an immature ovum
|
follicle
|
|
|
The ovaries consist of thousands of...
|
follicles
|
|
|
Follicle cells produce...
|
estrogen
|
|
|
Once a month, an immature ovum is released from the ovary into the abdominal cavity and drawn into...
|
the oviduct
|
|
|
Each fallopian tube opens into a muscular chamber called the...
|
uterus
|
|
|
The site of fetal development is the...
|
uterus
|
|
|
The lower, narrow, end of the uterus is called the...
|
cervix
|
|
|
The cervix connects with the vaginal canal, which is the site of...
|
sperm deposition during intercourse and also the passageway through which a baby is expelled ruing childbirth
|
|
|
The ovaries synthesize and secrete the female sex hormones including...
|
estrogens and progesterone
|
|
|
The secretion of both estrogens and progesterone is regulated by...
|
LH and FSH
|
|
|
LH and FSH are regulated by...
|
GnRH
|
|
|
LH stands for....
|
leutenizing hormone
|
|
|
FSH stands for...
|
follicle stimulating hormone
|
|
|
Steroid hormones necessary for normal female maturation
|
estrogens
|
|
|
Estrogens stimulate...
|
the development of the female reproductive tract and contribute to the development of secondary sexual characteristics and sex drive
|
|
|
Estrogens are responsible for...
|
the thickening of the endometrium
|
|
|
Estrogens are secreted by...
|
ovarian follicles and corpus luteum
|
|
|
Steroid hormone secreted by the corpus luteum during the luteal phase of menstrual cycle
|
progesterone
|
|
|
Progesterone stimulates...
|
the development and maintenance of the endometrial walls in preparation for implantation
|
|
|
The phases of the menstrual cycle are...
|
1. follicular
2. ovulation 3. luteal 4. menstruation |
|
|
The follicular phase begins with the...
|
cessation of the menstrual flow from the previous cyle
|
|
|
During the follicular phase, ___ from the _____ promotes the development of the _____, which grows and begins secreting _____
|
1. FSH
2. anterior pituitary 3. follicle 4. estrogen |
|
|
Follicles mature during the...
|
follicular phase
|
|
|
Ovulation is triggered by...
|
an LH surge at midcycle
|
|
|
A rupture follicle becomes the...
|
corpus luteum and secretes estrogen and progesterone to build up uterine lining in preparation for implantation
|
|
|
As the corpus luteum is formed...
|
LH and FSH are inhibited
|
|
|
If fertilization doesn't occur...
|
the corpus luteum atrophies, progesterone and estrogen levels decrease, menses occurs, and LH and FSH levels begin to rise again
|
|
|
A mature ovarian follicle bursts and releases an ovum during...
|
ovulation
|
|
|
The surge in LH which causes ovulation is preceded by...
|
a peak in estrogen levels
|
|
|
After ovulation...
|
LH induces the ruptured follicle to develope into the corpus luteum, which secretes estrogen and progesterone
|
|
|
Progesterone in the luteal phase causes...
|
the glands of the endometrium to mature and produce secretions that prepare it for implantation of embryo
|
|
|
The maintenance of the endometrium requires...
|
estrogen and progesterone
|
|
|
If the ovum is not fertilized, the corpus luteum atrophies and...
|
resulting drop in progesterone and estrogen levels causes the endometrium to slough off, giving rise to menses
|
|
|
If fertilization occurs...
|
the developing placenta produces hCG to maintain the corpus luteum and a supply of estrogen and progesterone until the placenta takes over production of these hormones
|
|
|
In regard to alternation of generations, the evolutionary trend has been towards...
|
increased dominance of sporophyte generation
|
|
|
The haploid gametophyte generation produces...
|
gametes by mitosis
|
|
|
Union of male and female gametes at fertilization in plants...
|
restores diploid sporophyte generation
|
|
|
Gametophytes reproduce _____ and sporophytes reproduce______
|
sexually; asexually
|
|
|
The gametophyte is the dominant generation in...
|
mosses
|
|
|
In mosses, the sporophyte generation...
|
is a smaller short-lived organism that depends on the gametophyte for energy and nutrients and grow on top of the gametophytes and produce spores that develop into gametophytes
|
|
|
The diploid sporophyte generation produces...
|
haploid spores by meiosis which divide by mitosis to produce haploid gametophyte generation
|
|
|
In ferns, the dominant generation is...
|
sporophyte
|
|
|
In ferns, the sporophyte generation releases...
|
spores from the undersides of its leaves that develop into small heart shaped gametophytes
|
|
|
Angiosperms have gametophytes that consist of...
|
a few cells that exist for a very short time
|
|
|
Flowering plants are called...
|
angiosperms
|
|
|
The reproductive structure of angiosperms
|
flower
|
|
|
The male organ of the flower
|
stamen
|
|
|
Stamens consist of...
|
filament and anthers
|
|
|
The stalk like _____ of the stamen has a terminal sac called the _____
|
filament; anther
|
|
|
The anther produces...
|
haploid spores that develop into pollen grains
|
|
|
The female organ of the flower
|
pistil
|
|
|
The pistil consists of...
|
stigma, style, and ovary
|
|
|
The sticky to part of the pistil which catches pollen
|
stigma
|
|
|
The tube-like structure connecting the stigma to the ovary at the base of the pistil
|
style
|
|
|
The enlarged base of the pistil that contains one or more ovule
|
ovary
|
|
|
Specialized leaves surrounding and protecting the pistil
|
petals
|
|
|
Petals are used to...
|
attract insects which transfer pollen
|
|
|
Green leaves that cover and protect the flower bud during early development
|
sepals
|
|
|
The pollen grain is the...
|
male gametophyte
|
|
|
The pollen grain contains...
|
a tube nucleus and a generative nucleus formed by mitosis of a microspore
|
|
|
The female gametophyte is the...
|
embryo sac and contains nuclei including two polar nuclei (endosperms) and an egg nucleus
|
|
|
In flowering plants, fertilization occurs...
|
when the sperm nuclei enter the embryo sac; one sperm nucleus fuses with the egg nucleus to form the diploid zygote which develops into the embryo; the other fuses with the two polar bodies to form the endosperm (3N) which provides food for the embryonic plant
|
|
|
In dicotyledonous plants...
|
ht endosperm is absorbed by the seed leaves
|
|
|
The precursor of the upper stem and leaves
|
epicotyl
|
|
|
The seed leaves
|
cotyledons
|
|
|
Develops into the lower stem and root
|
hypocotyl
|
|
|
Develops from the outer covering of the ovule
|
seed coat
|
|
|
Most seeds develop in the...
|
fruit
|
|
|
The fruit serves as a means of...
|
seed dispersal
|
|
|
Apical meristem is found in...
|
tips of roots and stems
|
|
|
Apical meristems allow...
|
growth in length only
|
|
|
The lateral meristem or cambium is located...
|
between the xylem and phloem
|
|
|
The lateral meristem allows...
|
growth in diameter and can differentiate into new xylem and phloem cells
|
|
|
Cambium tissue is predominant in...
|
woody dicots like oaks
|
