Unit 3- Biology

Select all of the cell cycle checkpoints.

-M checkpoint -G1 checkpoint -G2 checkpoint

Which is true of daughter cells produced by meiosis II?

-They are genetically variable -They are haploid

During spermatogenesis, which of the following cells is the first to become haploid? A. Secondary spermatocyte B. Primary spermatocyte C. Spermatogonium D. spermatid E. Sperm cells

A. Secondary spermatocyte

Inside a dividing cell, what are the condensed molecules of DNA and proteins called

Chromosomes

The sperm teil contains microtubules similar to what other structure of cells?

Cilia

Birth control pills

Combine progesterone and estrogen to shut down pituitary production of FSH and LH, preventing ovulation

No replication of DNA occurs between meiosis I and meiosis II. This period of time is called

Interkinesis

Sister chromatids form while the cell is in

Interphase

Which of the following statements about crossing over is TRUE?

It results in homologues exchanging genetic material

Intrauterine device IUD

Molded plastic inserted into the uterus to prevent implantation

Which of the following is a correct sequence of cells in spermatogenesis?

Spermatogonium -> primary spermatocyte -> secondary spermatocyte

What is the function of the mitochondria in the case of the sperm?

To provide energy for movement

On the other hand, an individual with the sex chromosomes XXY is a _________ affected by a disease called ______ syndrome.

male Klinefelter

During what phase of meiosis do fully formed spindles align a haploid number of chromosomes along the metaphase plate?

metaphase II

This image depicts which phase of meiosis (in an organism with n=2)?

metaphase II

When cancer cells invade underlying tissue, they can begin new tumors far from the primary tumor. This spreading cancer throughout the body is called

metastasis

The ability of a tumor to spread far from the primary tumor

metastasisM

During cleavage, a solid ball of cells called a _______ is produced.

morula

Which of the following is a nucleotide sequence that stimulates mitosis and causes cancer?

oncogene

The G2 phase of the cell cycle is also known as the

pre-mitotic phase

The spindle apparatus is fully formed by the end of

pro metaphase II

The phase of meiosis shown here is

prophase II

Gene mutation can change a ________ into an oncogene.

proto-oncogenes

Because each homologue has two sister chromatids, four chromatids are in close association. Each set of four chromatids is called a

tetrad

The assembly of transcription factors beings

upstream from the transcription site.

Both sperm (semen) and urine exit the male body via the ______ , thus this structure is said to be a part of the urinary and reproductive systems.

urethra

A single diploid cell called a ________ is formed by the fusion of haploid gametes.

zygote

Match the term with its correct description: -autosome -sex chromosome

-22 pairs; do not determine gender -1 pair; determine gender

During the follicular phase, FSH is produced by the _______ pituitary gland, stimulation the development of the ________.

-Anterior -Follicle

Proto-oncogene

-Can become an oncogene -Codes for proteins that promote the cell cycle -Codes for a meter of the stimulatory pathway -Codes for proteins that inhibit apoptosis -The end point of a normal stimulatory pathway

Prophase- metaphase- anaphase- telophase-

-Chromatin is condensing, and nuclear envelope is fragmenting. -centromeres of duplicated chromosomes are aligned at the equator. -Sister chromatids part and become daughter chromosomes that are pulled toward the poles. -Daughter cells are formed as nuclear envelopes and nucleoli reappear.

Tumor suppressor gene

-Codes for proteins that inhibit the cell cycle -Codes for proteins that promote apoptosis -Can become a mutated tumor suppressor gene -Stops cells from dividing further

Select the functions of mitosis

-Maintains the chromosome number of daughter cells as the parent cell. -produce two identical daughter cells -allows for growth and repair

Sexual Reproduction

-Male gametes fertilize female gametes to give rise to offspring -Allows for genetically diverse offspring -Dominate reproduction in animals, birds, fish, amphibians, and reptiles.

Which events occur in the G2 phase of the cell cycle?

-Rapid cell growth -synthesis of proteins

Meiosis

-Requires two nuclear divisions -every cell produces 2 daughter cells -results in diploid cells -daughter cells are genetically different

Asexual Reproduction

-Single parents give rise to genetically identical offspring -Allows organisms to reproduce quickly -Includes parthenogenesis and budding -Seen in earthworms, starfish, sponges, and jellyfish.

Select all of the following which describe the effects of monosomy and trisomy.

-absence of an autosomal chromosome is lethal in human embryos -those with sex aneuploidies do survive as long as they have at least one X chromosome -only one autosomal trisomy survives for any length of time.

Select all of the following that are required in the growth and development of an organism.

-apoptosis -mitosis

Select all of the following that characterizes cancer. Select all of the below characteristics that describe cancer cell.s

-cancer cells undergo angiogenesis and metastasis -cancer cells have abnormal nuclei -cancer cells form tumors -cancer cells lack differentiation

Carcinoma- Sarcoma- Leukemia-

-cancer of the tissue type that lines organs -cancer arising in muscle or bone and cartilage -cancer of the blood

As progesterone levels rise, feedback mechanisms cause the _______ to degenerate, causing progesterone levels to drop.

-corpus luteum

Select all of the following that occur during Prophase I of meiosis in animal cells?

-crossing-over -homologous pairs become visible -nuclear envelope fragments

Select all of the following that increase genetic variation.

-crossing-over -sexual reproduction -independent assortment

Select all of the following that characterize telophase II.

-cytokinesis takes place -nuclei reform -spindle disappears

A cell in telophase of mitosis would have which of the following characteristics?

-daughter chromosomes aggregated at opposite poles of the cell -nucleoli reappear

A cell in anaphase would have which of the following characteristics?

-daughter chromosomes are near opposite poles of the cell -condensed chromosomes

Select all of the following that characterizes Turner syndrome.

-do not undergo puberty of menstruate -females have only a single X chromosomes -individuals tend to be short, with broad chest and widely spaced nipples

Select all of the following that characterizes meiosis.

-each daughter cell has one of each kind of chromosome -results in four daughter cells -reduction division

in the normal sequence of events, male sexual arousal leads to ______. Select all that apply.

-ejaculation -orgasm

Which of the following processes are a part of the cell cycle?

-equal distribution of chromosomes between daughter cells. -replication of a cells chromosomes -partitioning of cellular components between daughter cells

Select all of the following that characterizes the nuclei of a cancer cell.

-gene amplification -abnormal number of chromosomes -nuclei are enlarged

Select all that apply. The female clitoris

-has twice as many nerve endings as the penis -has a shaft of erectile tissue -functions as a sexually sensitive organ -is capped by a pea-shaped glans

Select all fo the following that characterize meiosis I.

-homologous chromosomes come together and line up side by side -daughter nuclei are haploid -first reduction division

Select all of the following that characterize independent assortment.

-homologous pairs align independently at the equator -occurs during meiosis -increases genetic variation

Estrogen levels rise, stimulation the ________ to secrete GnRH, leading to a surge in ______ production.

-hypothalamus -LH

Select all of the following that characterizes a karyotype.

-identifies the size and shape of chromosomes -chromosomes are stained and show dark and light cross bands -shows that humans have 23 pairs of chromosomes

Select all of the following that characterize crossing-over.

-increases genetic variation -exchange of genetic material -occurs while homologues are in synapsis -occurs during meiosis I

Select all of the components of the vulva from the choices below.

-labia majora -labia minora -mons pubis

Match the stem cell with its correct description. -Embryonic stem cell -adult stem cells

-long life span; produce a variety of tissues -difficult to glean from human body; do not multiply readily in the laboratory.

During the __________, LH promotes development of the corpus luteum, whose function is to produce ________.

-lutheal phase -progesterone

The endometrium begins to disintegrate, causing __________ to occur.

-menstruation

Select the components of menstrual flow from the choice listed below

-mucus -endometrium tissue -blood

Select all of the following that characterizes a cancer cell's lack of differentiation.

-nonspecialized -do not contribute to functioning of a body part -enter the cell cycle repeatedly

Mitosis- Cytokinesis-

-nuclear division -division of the cytoplasm

Select all of the following that characterize nondisjunction

-occurs during meiosis II when the sister chromatids fail to separate and both daughter chromosomes go into the same gamete -occurs during meiosis I when homologues fail to separate and both homologues go into the same gamete

Monosomy Trisomy

-one less chromosome than usual -one more chromosome that usual

Select all of the following that characterizes a homologous chromosome pair.

-one of the pair came from the father and one of the pair came from the mother -homologous chromosomes have genes for the same traits

Typically, on the 14th day, this causes _____ to occur where the ________ is released.

-ovulation -oocyte

Which two of the following describe apoptosis?

-programmed cell death -a series of intracellular events leading to destruction of the cell

Estrogen produced by the ovarium follicle causes the endometrium to begin to thicken, starting the ___________.

-proliferative phase

Mitosis

-requires one nuclear division -every cell produces 4 daughter cells -results in haploid gametes -daughter cells are genetically identical

The increase in progesterone causes the endometrium to double in thickness and produce a thick mucoid secretion, starting the _______.

-secretory phase

Select all of the following that increase genetic variation

-sexual reproduction -independent assortment -crossing-over

Select all of the following that characterize a centriole.

-short cylinders of microtubules located in centrosomes. -found in animal cells.

Select all of the following that characterize Down syndrome.

-short stature, eyelid fold, flat face, round hear -chances of a woman having a child with Down syndrome increases with age -trisomy 21

Select all of the following that characterizes an aster

-short, spindle fibers -found in animal cells -radiate from the pair of centrioles located within each centrosome

Select all of the following that characterize a karyotype.

-shows that humans have 23 pairs of chromosomes -identifies the size and shape of chromosomes -chromosomes are stained and show dark and light cross bands

Select all of the following that occur during meiosis II.

-sister chromatids separate, becoming daughter chromosomes -four daughter cells result

Select all of the following that characterize Klinefelter syndrome?

-slow to learn but not severely intellectually disabled. -large hands and feet and very long arms and legs -testes and prostate glad are underdeveloped.

Select all fo the events that characterize telophase I.

-spindle apparatus disappears -nuclei reform around separated homologues

Match the type of asexual reproduction on the left with its description or the animal that uses it on the right. Gemmules Budding Fragmentation parthenogenesis

-used by sponges -a new individual arises from an outgrowth of a parent -well known amount sponges, planarians, and echinoderms -unfertilized eggs develop into complete haploid individuals

arrange the events surrounding the ovarian cycle in order, beginning just after mensuration.

1. the follicular phase 2. ovulation 3. the luteal phase

Consider a cell that has three pairs of chromosomes. What fraction of the gametes produced from this cell will contain only maternal chromosomes?

1/8

How many bivalents are formed in a cell with 20 chromosomes at the beginning of meiosis I?

10

What is the diploid number of chromosomes for a species in which the sperm cell contains 5 chromosomes?

10

What is the diploid number of chromosomes for a species in which the sperm cells contain 5 chromosomes?

10

If the standard number of chromosomes in an organism's cells is 12, how many chromosomes will be in cells produced by mitosis?

12

Consider a cell that has four pairs of chromosomes. What is the number of possible chromosome orientations in that cell?

16

Which of the following describes meiosis II in humans?

1N -> 1N

Arrange the following events in the proper order in which they occur during meiosis I. 1=separation of homologous chromosomes 2=synapsis 3=crossing-over 4=independent assortment

2,3,4,1

A _______ is the display of chromosomes and in humans there are _____ pairs of chromosomes.

23

The amount of time it takes for a cell to complete the cell cycle varies. However, an adult mammalian cell can actually finish the cell cycle in about

24 hours

How many chromosomes are in somatic cells in humans?

46

Humans have a total of ______ single chromosomes, which is the _________ number of chromosomes.

46 diploid

If a certain eukaryotic organism had 12 chromosomes in its somatic cells, what is this organism's haploid number?

6

The mitotic phase shown here is

Anaphase

What is the mitotic phase during which sister chromatids move toward the poles of the spindle?

Anaphase

Homologous chromosomes are moved to opposite poles of the cell during what meiotic phase?

Anaphase I

The phase of meiosis shown here is

Anaphase I

________ refers to the formation of new blood vessels.

Angiogenesis

Match the following inherited cancer causing genes with the type of cancer it causes

BRCA- breast cancer RB- retinoblastoma RET-thyroid cancer

_______ division and ________ are two opposing processes that keep the number of cells in the body at an approximate level.

Cell, apoptosis

The diffuse, granular combination of DNA and proteins is called

Chromatin

After mitosis, how do daughter cells compare to the parent cell?

Daughter cells have the same number and kinds of chromosomes as the parent cell.

An individual with an extra copy of the 21st chromosome has trisomy 21 or _________.

Down syndrome

How does meiosis differ from mitosis?

During meiosis crossing-over occurs, and there are four haploid daughter cells that are produced.

All of the cells of a sexually reproducing organism are diploid.

False

At full maturity, an oocyte is located in the corpus luteum.

False

Daughter cells produced in meiosis are identical.

False

During ovulation, the oocyte is surrounded by some of the cells of the cumulus mass called the corona radiate.

False

Germ-line cells are haploid but gametes are diploid,\.

False

Meiosis II of spermatogenesis results in the formation of secondary spermatocytes.

False

New cells are produced only when needed to repair damaged tissue.

False

Replication of chromosomes occurs between meiosis I and meiosis II.

False

True or False: All animals cells have the same number of chromosomes

False

True or False: During metaphase II, homologous pairs of chromosomes align along the metaphase plate.

False

True or false: photo-oncogenes cause cancer by stimulating the cell cycle

False

An individual with a single X chromosomes is a __________ affected by a disease called ______ syndrome.

Female Turner

An original diploid parent cell will produce how many daughter cells when meiosis is complete?

Four

The cell cycle checkpoint that monitors the viability of DNA is

G1

Which is the longest phase of the cell cycle for most cells?

G1

Match the cell cycle checkpoint with its correct description.

G1- if the cell passes this checkpoint, the cell is committed to divide. If the cell does not pass this checkpoint, it can enter G0. G2-ensures the DNA has replicated. M-makes sure chromosomes are going to be distributed accurately to the daughter cells.

During the ______ checkpoint, the cell cycle hesitated and ensures the DNA has replicated.

G2

Which part of the mammalian sperm contains the nucleus?

Head

Contraceptive implants

Implanted under skin and use progesterone to disrupt ovulation

In humans, fertilization occurs _______, as does the development of offspring.

Internally

The stage of the cell during which growth and DNA synthesis occur when the nucleus is not actively dividing is

Interphase

What does it mean that the sperm is "haploid"?

It contains one half the complement of chromosomes.

Female condom

Large polyurethane tube that fits onto the cervix and is worn by a woman to prevent sperm from entering the cervix.

Male condom

Latex sheath covering the penis to prevent sperm from entering a woman

A testis is composed of compartments called _____, each of which contains one to three tightly coiled _________ that are packed with cells undergoing spermatogenesis.

Lobules seminiferous tubules

What checkpoint ensures that the spindle apparatus and the chromosomes are properly aligned?

M

the checkpoint for the cell cycle are abbreviated _______, ________, and ________.

M, G1, G2

These newly formed cells undergo ____ to become spermatids that contain the ____ number of chromosomes and then later differentiate into sperm.

Meiosis Haploid

Which phase of the mitotic cell cycle is shown here?

Metaphase

________ is the mitotic phase during which chromosomes are aligned along the center plane (equator) of the cell.

Metaphase

Random orientation of homologous chromosomes occurs in _________ of meiosis.

Metaphase I

The phase of meiosis shown here is

Metaphase I

By which mechanism do normal body cells, such as skin cells, divide and multiply?

Mitosis

Which process produces daughter cells which are genetically identical to each other and to the parent cell?

Mitosis

Select the types of cells that are more apt to be in G0 than other types.

Muscle, nerve

Contraceptive injections

Progesterone, or progesterone and estrogen that is injected intravenously

__________ is the mitotic phase during which chromatin condenses and spindle fibers begin to form.

Prophase

which phase of the mitotic cell cycle is shown here?

Prophase

During ________ __________ of meiosis, the spindle forms, chromosomes condense, the nuclear envelope fragments, the nucleolus disappears, homologous chromosomes pair off, and crossing-over occurs.

Prophase I

Which of the following properly lists the sequential order of meiotic stages?

Prophase I, Metaphase I, Anaphase I, Telophase I, Prophase II, Metaphase II, Anaphase II, Telophase II

The correct order for the phases of mitosis is

Prophase, Metaphase, anaphase, and telophase

Select all of the following that are phases of mitosis

Prophase, anaphase, telophase, metaphase.

During the __________ stage of interphase, a eukaryotic cell replicates its DNA.

S

In which phase of the cell cycle are the chromosomes replicated?

S

Sister chromatids form during which phase of the cell cycle?

S

Sister chromatids form during which phase of the cell cycle?

S phase

What would be gained by coaxing stem cells to become specialized cells?

Scientists would achieve the goal of replacing diseased or damaged tissues.

Testosterone brings about and maintains the male ____ sex characteristics that develop during the time of ______.

Secondary puberty

When a primary follicle enlarges, and there are several layers of granulose cells, it is called a

Secondary follicle

Spermatogenesis occurs in the

Seminiferous tubules

What is the difference between how sex cells are created and how typical somatic cells are replicated?

Sex cells are created by meiosis, and somatic cells by mitosis.

Which of the following is characteristics of the S phase of the eukaryotic cell cycle?

Synthesis of DNA

The phase of mitosis shown in this illustration is ________.

Telophase

The phase of meiosis shown here is

Telophase II

Sperm are produced by the ____ and during ejaculation they are released in a whitish basic, lubricative fluid called _____ which contains ______ and allows for sperm motility.

Testes Semen Nutrients

The main sex hormone in males is

Testosterone

The main sex hormone in males is ______ and it essential for normal development and functioning of the male sexual organs.

Testosterone

The series of events that result in the duplication of a cells genetic material and division of the cell is called

The Cell Cycle

How do the nuclei of cancer cells differ from normal cell nuclei?

The cancer cell nuclei are enlarged, have abnormal chromosomes, and exhibit more frequent gene amplification.

What is DNA?

The material that carries genetic information from one generation to the next

If the head of the sperm were missing the enzymes described in the video, what would be the consequences ?

The sperm could not fertilize the egg.

Which of the following statements about basal transcription factors is TRUE?

They are essential for transcription and cannot increase the rate of transcription by themselves.

How do cells produce new cells?

They divide and create two new cells from a single parent cell

At the end of meiosis I, there are two haploid cells, each with two sister chromatids per chromosome.

True

Chromosome duplication occurs prior to both mitosis and meiosis.

True

Crossing-over allows the reassortment of linked genes

True

Crossing-over occurs during prophase I of meiosis.

True

During spermatogenesis, spermatids differentiate into sperm cells.

True

Eukaryotic transcription factors include activators and coactivators.

True

In animal cells, cell division is accomplished by the formation of a cleavage furrow.

True

Independent assortment occurs in prophase I.

True

Sexually reproducing species produce both sex cells (gametes) and somatic (non-sex or body) cells.

True

The actual structure that homologues bind to is called the spindle axis.

True

The period between meiosis I and II is termed interkenisis.

True

The region of the cell where chromosome pairs line up is referred to as the plate!

True

True of False: Two daughter cells produced by mitosis will have the same number of chromosomes as the original parent cell.

True

Other organisms, such as mammals, are ________, meaning they use a _________ to support the developing young.

Viviparous placenta

Due to the lack of a second _______ chromosomes, these individuals with Turner syndrome will most likely exhibit underdeveloped secondary sex characteristics.

X

Ordinarily, cytokinesis begins during telophase and continues

after the nuclei are formed until there are two daughter cells.

Each homologue may have a different version of a gene. These alternate versions of a gene are called

alleles

Alternate versions of a gene for a particular trait, such as finer hair of type of earlobe, are called ______ and occur at the same location on each ______ chromosome.

alleles homologous

During ___________ of meiosis, homologous chromosomes are drawn toward opposite poles of the cell.

anaphase I

Which phase in an organism with n=2 for each cell does this image depict?

anaphase II

What do you call the chromosome anomaly when a gamete without the normal number of chromosomes, fuses with a normal gamete and continues to develop.

aneuploidy

To increase the blood supply to a growing tumor, tumor cells release growth factors that induce

angiogenesis

During the cell cycle, if the DNA is damaged beyond repair, a signaling protein brings about the death of the cell. This programmed cell death is called

apoptosis

which of the following events occur during prophase I?

breakdown of nuclear envelope, condensation of chromosomes, and movement of centrosomes.

A carcinogen is a type of mutagen that leads to the development of

cancerW

A mutagen that leads to the development of cancer is known as a

carcinogen

Any tissue that already has a high rate of cell division is inherently more susceptible to the development of cancer, which is called

carcinogenesis

The structural and functional unit of life is the

cell

The G1 phase of the cell cycle is characterized by

cell growth

Plant cells divide their cytoplasm by forming a

cell plate

What is the chromosome configuration in prophase II?

cells have one chromosome from each pair of homologues.

A cell organelle, existing in pairs, that occurs in the centrosome and may help organize a mitotic spindle for chromosome movement during animal cell division is called a

centriole

Sister chromatids are held together at a constricted area called the

centromere

What is the microtubule organizing center of the cell?

centrosome

A ______ is the microtubule organizing center of the cell and it divides at the start of _________.

centrosome, nuclear division

When a cell is about to divide, _______ become highly child and condensed into the chromosomes.

chromatin

Just prior to cell division, DNA condenses into rod-shaped structures called

chromosomes

Cellular division without growth is called

cleavage

Cytokinesis in animal cells begin with the formation of a ____ _____ , which is shown in the figure here.

cleavage furrow

The sexual union to facilitate this is called ________ and occurs when a male uses his ______ to deposit sperm into a female _______.

copulation penis vagina

Homologous chromosomes sometimes exchange genetic material in an event called

crossing-over

Which of the following is unique to meiosis?

crossing-over

Which of the following occurs only in meiotic division?

crossing-over

Divison of cellular cytoplasm is called

cytokinesis

Because a sperm from one individual fertilizes an egg from another individual, the offspring are genetically ______.

diverse

Individuals with Down syndrome usually get two copies of the X chromosomes from the _______; however, recent studies indicate that in 23% of the cases the ________ contributed the extra chromosome.

egg sperm

Many aquatic organisms practice a type of sexual reproduction where the egg is fertilized __________.

externally

At the end of meiosis II, there are

four haploid cells, with each chromosome consisting of a single chromatid.

Gonad is a collective term for specialized organs such as ovaries and testes. These structures produce cells called ___________.

gametes

Usually, the meiotic daughter cells mature into cells called

gametes

Daughter cells produced by mitosis will be

genetically identical

What are the functions of mitosis in multicellular eukaryotic organisms such as plants and animals?

growth, development, and repair

Daughter cells produced in meiosis have

half the number of chromosomes as daughter cells produced in mitosis.

Humans have 23 pairs of chromosomes, which is the _______ number, of which 22 pairs are called _______ and one pair is called ______.

haploid autosomes sex chromosomes

The pair of chromosomes circled in this karyotype are called

homologous chromosomes

A display of stained chromosomes is called a

karyotype

Spindle fibers are attached to a disk-shaped structure within the centromere of a chromosome during mitosis and meiosis at a protein complex known as the

kinetochore

The fertilized egg develops into an immature ______.

larva

Which of the following has an antrum?

mature follicle

Which of the following is involved in ovulation?

mature follicle

The gametes, eggs and sperm, are produced by which process?

meiosis

Which form of cell division is illustrated in this diagram?

meiosis

synapsis and the presence of haploid daughter nuclei occur during which division of meiosis?

meiosis I

The periodic shedding of blood and tissue from the endometrium in humans is called

menstruation

During what phase of meiosis I do the homologous pairs of chromosomes align at the equator?

metaphase I

_______ is the type of cell division that allows for growth and repair of body cells.

mitosis

centromeres divide in

mitosis and meiosis II

Which of the following lists the cell cycle phases in correct sequential order? (Remember, the description of a cycle can start at any stage.)

mitosis, G1,S,G2

How do monosomy and trisomy affect the individual?

monosomy could be lethal, and trisomy survivors would have characteristic anomalies.

How do mutations that are due to environmental assaults affect the development of cancer?

mutations due to different environmental assaults can result in abnormal growth of cells and eventually cancer.

A crossover is meiosis is an exchange of genetic material between

nov-sister chromatids of homologous chromosomes.

Eggs are produced in the ____ and released once a month, and, if fertilized by sperm, develop into viable offspring in the ____.

ovaries uterus

Other organisms, such as oysters, are __________, meaning they retain their young until they are developed enough to fend for themselves.

ovoviviparous

An enlarged tip covered by foreskin and a shaft of spongy erectile tissue are characteristic of which reproductive organ?

penis

Any embryonic stem cell that is able to become any type of tissue in the body is

pluripotent

An individual with three or more copies of each chromosome is a

polyploid

The phase of meiosis that is shown here is

prophase I

which of the following events occur during anaphase I?

separation of homologous chromosomes

Terrestrial organisms practice ______ reproduction where the egg is fertilized ________.

sexual internally

What are the factors that increase genetic variation?

sexual reproduction, independent assortment, crossing-over

A disease that is passed between people during sexual relations is called a ________ _____ disease.

sexually transmitted

During anaphase II of meiosis, what separates and moves to opposite poles?

sister chromatids

Genetically identical chromosomal units which are held together by the centromere are called

sister chromatids

Genetically identical chromosomal units which are held together by the centromere are called _______ _________.

sister chromatids

Separation of _______ occurs in anaphase II or meiosis.

sister chromatids

Following DNA replication during the cell cycle a chromosomes has two parts called __________ that are duplicates of each other and their alleles are exactly the same.

sister chromatids.

Diaphragm

soft latex cup that covers a woman's cervix, preventing sperm from entering

The ______ __________ functions to separate chromatids during cell division.

spindle apparatus

The resulting daughter centrosomes produce the _______, which assists the separation of the ________ as they move to the opposite poles of the spindle.

spindle apparatus, chromatids

What is the function of stem cells?

stem cells divide and produce cells that will become mature.

A mutation in the tumor ______ gene could lead to uncontrolled cell division and a tumor.

suppressor

The term __________ refers to the lying side-by-side of homologous chromosomes to form a tetrad during prophase I.

synapsis

Chromosome anomalies cause certain characteristics to commonly appear together. This is referred to as a

syndrome

During _______ I of meiosis the spindle disappears and interkinesis follows.

telophase

The phase of meiosis that is shown here is ________ _________.

telophase It

True or false: The gene p53 is a tumor suppressor gene that is often found mutated in human cancers.

true

A _______ forms when cancer cells invade a tissue and cause cells to pile on top of one another and grow in multiple layers.

tumor

The number of cells produced in meiosis is

twice the number of cells produced in mitosis

Due to having ________ X chromosomes, these individuals will most likely exhibit reduced male secondary sex characteristics.

two

Sex chromosomes determine gender and females have _______ chromosomes while males have __________ chromosomes.

two X X and Y

A tetrad is made up of

two homologous chromosomes, each consisting of two chromatids.

The first cell of the new individual is called a

zygote