Biology Chapter 5

Chromosomes are duplicated during ______

Interphase

_____ is the union of gametes from two different parents

Sexual reproduction

Explain why a male can never be a carrier in a sex linked disease (on the X-chromosome)

Since a male only has one X chromosome, he only has one allele of any genes on that chromosome

Two chromatids attached by a centromere are referred to as sister chromatids. How many total chromatids would a human skin cell contains after DNA has been duplicated?

92

What is the unique challenge associated with studying human genetics?

A geneticist cannot mate two humans to see what traits the offspring would have.

Law of segregation

Allele pairs separate from one another during gamete formation

Law of independent assortment

Allele pairs separate independently of one another during gamete formation

A cell biologist observes a cell under a microscope an determines that the cell contains nine chromosomes. Is that cell diploid of haploid?

The cell is haploid because the cell has an odd number of chromosomes, which would have occurred as a result of homologous chromosomes separating during meiosis I

A normal human egg or sperm has 23 chromosomes, which is exactly one half the number of chromosomes a somate contains. Briefly explain what would happen to the chromosome number every generation if gametes were actually diploid

The number of chromosomes would double from generation to generation

You are a combination of genetic material rom both of your parents. Which cells from your parents united during fertilization to from you? What are very important items in both of those cells from your parents?

This is true because your father and mother both contributed to your genetic makeup through their sperm and egg, respectively. Each of these cells contained chromosomes.

Many of your nerve cells never divide. True or False

True

Only 0.5% of your DNA accounts for your unique characteristics. True or False

True

While most plants reproduce sexually, many can reproduce asexually as well. True or False

True

Incomplete dominance

When neither allele is fully dominant to the other

Turner syndrome

XO, female

Triple-X syndrome

XXX, female

Klinefelter syndrome

XXY, male

Jacob's syndrome

XYY, male

Diploid

a cell from a human liver, a human zygote, a cell from a human heart

Haploid

a human egg, a human sperm

Which of the following is a function of cell division?

all of the above- growth/development of the organism, production of egg and sperm, replacement of lost or damaged cells

alternate forms of a gene are referred to as _____

alleles

A cell has 22 autosomes and an X chromosome. Which of the following could that cell be ?

an egg cell, a sperm cell

There are 46 human chromosomes. Of these 46, 44 are _____ and 2 are _____

autosome, sex chromosomes

similarities of mitosis and meiosis

both types of cell division, both are preceded by chromosome duplication

a heterozygous person who has one disease allele and one normal allele is referred to a ______

carrier

The______ is the series of events that occurs from the time a cell is created until the time that cell undergoes its own division

cell cycle

Interphase

cell is performing normal functions, chromosomes duplication occurs

The _____ is a fundamental concept of biology, which states that life is base on cells, and that cells arise from existing cells.

cell theory

sister chromatids are attached at the _______

centromere

yellow is to pea seed color as _______ is to coat color in labradors

chocolate

Inside a cell, DNA is associated with proteins. This combination of protein and DNA is known as ______

chromatin

The process by which cytokinesis occurs in animal cells is known as _____

cleavage

Division of the cytoplasm into two new cells is referred to as ______

cytokinesis

a genetic cross in which two individual are mated where each one is heterozygous for two characters ____

dihybrid cross

A skin cell is to a somatic cell as a(n) ______ is to a gamete

egg

Every one of the 37 trillion cells in a person's body can ultimately be traces back to one original cell. What is that cell?

every cell in a person's body is descendant from the zygote that was produced when his or her father's sperm fertilized his or her mother's egg.

list three human characters and then provide two traits for each character

eye color- hazel and blue, hair color- black and red, hairline- straight and widow's peak

______ is the transmission of traits from generation to generation, while _____ is the study of that trait transmission

heredity, genetics

_______ contains the same genes at the same locations

homologous chromosome

purple flower color is to pea plant flower color as red hair is to ______

human hair color

crossing over produces _____

hybrid chromosomes

Each homologous pair of chromosomes can line up in one of two orientations. This kind of alignment is known as ______

independent assortment

Genes A and B are located very close together on a chromosome. These two genes would be considered _____

linked genes

uncondensed chromosomes

made of chromatin, contains genes

condensed chromosome

made of chromatin, has centromere, consists of sister chromatids, contains genes

_____ is the type of cell division in animals that produce gametes

meiosis

what rule of inheritance is characterized by one gene affecting multiple characters?

pleiotropy

Using nuclear transplantation to produce a new animal is called ________.

reproductive cloning

Sexual reproduction

requires egg and sperm, involves fertilization, produces genetically different offspring

Genes on the X chromosome that control single human characters are referred to as ____

sex-linked genes

two students are presenting ideas to their study group on reproductive cloning. One student says that the surrogate mother does not pass on any traits to the developing organism, while the other student takes the position that the surrogate passes on traits to the offspring. Which student is correct?

surrogate mother did not contribute the donor nucleus or donor egg, and as such, she would not pass on any traits of the offspring

Which parent determines the sex of the offspring?

the father determines the sex of the offspring because the father produces two different populations of the sperm: one with the X and one with the Y chromosome.

Each row and column in a Punnett square represents a gamete that each parent can produce. Briefly explain why each gamete has inly one allele in it.

the gametes will have only one allele because they will be haploid and haploid cells only have one of each chromosome

There is a lot of excitement about the possibilities if stem cells in the use of therapeutic cloning. What characteristics of stem cells is the source of this power and the excitement about it?

the power of stem cells resides in the fact that stem cells can develop into every cell type in the body. In other words, stem cell could, in theory, be used to make replacement for organs and tissues

A zygote is created from a sperm that contains a Y chromosome. What will the sex of the individual be?

the sex of the individual will be a male

A human zygote is created from a sperm that contained an extra chromosomes 21. How many total chromosomes did the sperm contain? How many chromosomes would the resulting zygote have?

the sperm had 24 chromosomes and the resulting zygote had 47 chromosomes

a plant that produces yellow seeds inbred with a plant that produces green seeds. All of the seeds of the offspring are yellow. Which of the following explains this?

the yellow allele is dominant to the green allele

Which of the following is a similarity that meiosis shares with mitosis?

they both undergo chromosome duplication

Briefly explain why only chromosomes of a homologous pair can have their alleles referred to as homozygous or heterozygous

this is because only homologous chromosomes would have the same genes at the same physical locations on those chromosomes. Otherwise, the alleles of different genes would have no relationship.

Polygenic inheritance

when multiple genes affect one character

Pleiotropy

when one gene affects multiple characters

Codominance

when there are two alleles that are expressed equally in the heterozygous

what is the trait found with the highest frequency in nature?

wild-type trait

Can a karyotype be used to determine the sex of an individual? Briefly explain your answers either way.

yes, because you can use a karyotype to see chromosomes and place them into their homologous pairs. this would allow you to see the pair of ex chromosomes

What is the phenotype of an individual who is homozygous for freckles

A- Ff B- FF C-ff D- none of the above is phenotype D- none of the above is phenotype

The molecule of all organisms that stores all information is ____, which contains many units of hereditary information called _____ that are found on structures called _______

DNA, genes, chromosomes

A cell that is dividing rapidly can complete mitosis in just over an hour. True or False

False, a cell can complete mitosis in less than a minute

All human characteristics follow Mendel's rules. True or False

False, human blood type does not follow the rules of Mendel.

An abnormal gamete formed from nondisjunction always results in a zygote with the incorrect number of chromosomes. True or False

False, it depend on whether or not the nondisjunction occurred in meiosis I or II. If it occurred during meiosis II, then half of the gametes will have the correct number of chromosomes

a situation where a human is missing an autosome is not fatal. True or False

False, it is always fatal

At the end of meiosis I, the two cells are diploid. True or False

False, the two cells are haploid because homologous pairs of chromosomes separate during meiosis

Is it possible for a man with AB blood to have a child with O blood if he is married to a woman who has O blood. What are the possible phenotypes of his children.

No, because both A and B are dominant to O. If the woman has O blood then any child fathered by that man would have either A or B blood

Mendel's law of independent assortment is completely valid as long as the genes you are studying are on different chromosomes. True or False

True

list an example of a cell in your body that undergoes mitosis. How many chromosomes does that cell have?

a skin cell would under go mitosis. a human cell would normally have 46 chromosomes.

Mitotic phase

chromosomes are condensed, cell is dividing, sister chromatids are evenly distributed into two new cells

Which of the following is the correct sequence of event during mitosis?

chromosomes condense. chromosomes align, chromosomes split, nucleus reforms

Meiosis

chromosomes duplicate prior to division, chromosomes condense prior to division, as homologous pairs along the center of the cell

Mitosis

chromosomes duplicate prior to division, chromosomes condense prior to division, center of cell with each chromosome along a separate track

Organisms that are genetically identical and derived from a single parent are known as ____

clones

Briefly explain why the term crossing over is accurate for the process it names

crossing over is accurate because DNA is actually being exchanged between the two homologous chromosomes

During which specific stage of the cell is the cytoplasm distributed, which creates two new cells?

cytokinesis

Mitosis creates _____, while meiosis creates ______

diploid somates, haploid gametes

At the end of meiosis II, there are____ cells, and they are all ___

four, haploid

Mitosis is to a somate as meiosis is to _______

gamete

sexual reproduction produces a tremendous amount of diversity in organisms. List three ways in which this diversity is accomplished

independent assortment, random fertilization, crossing over

A _____ is a mating between two individual who are heterozygous for one character

monohybrid cross

When a gene has more than two alleles, it is said to have ______

multiple alleles

does the individual from the karyotype shown here have a normal number of chromosomes? If not, what syndrome does he or she have? how many total chromosomes would this person have?

no, she or he has down's syndrome/trisomy 21

The failure of chromosomes to separate properly is known as ______

nondisjunction

_____ is the process by which a scientist injects a nucleus from a donor cell into an egg that is lacking a nucleus

nuclear transplantation

Mitosis

produces diploid somates, produces genetically identical cells

Asexual reproduction

produces genetically identical offspring, produces genetically different offspring

Meiosis

produces haploid gametes, produces genetically different cells

The nuclear membrane breaks down during _____

prophase

List the stages of mitosis in order

prophase, metaphase, anaphase, telophase

crossing over creates chromosomes with new combinations of genes are called ______

recombinant chromosomes

A scientist adds a chemical to a dividing plant cell that keeps the cell plate from forming during cytokinesis. The chemical does not inhibit any other aspect of cell division except the formation of the cell wall through the inhibition of the cell plate. Would this result in one cell or two? Describe the number of chromosomes in the resulting cell/cells. Would they have original/normal amount of chromosomes?

this result would be that the resulting cell is roughly twice the size of a normal cell an would have twice as much genetic material/ DNA/chromosomes

An individual is determined to have Jacob's syndrome. Is it possible to determine which parent's gamete had the incorrect number of chromosomes? If so, which parent contributed the abnormal gamete?

yes, it is possible. Since the resulting zygote has two Y chromosomes, it had to be the sperm that brought two Y chromosomes to the egg. It would be impossible for a normal female to contribute an egg with a Y chromosome

What do you know for sure about the genotype of any organism whose phenotype is the recessive trait?

you would know that the pea plant has to be homozygous recessive for the genotype