bio topic 3 Flashcards by Nataliia Kovbas

What change causes sickle cell anemia?

Thymine replacing adenine in DNA

How well did you know this?

Not at all

Perfectly

What is a feature of human genome?

Mitochondrial DNA

How well did you know this?

Not at all

Perfectly

Which statements are characteristics of alleles?
I. Alleles differ significantly in number of base pairs.
II. Alleles are specific forms of a gene.
III. New alleles are formed by mutation.
A. I and II only
B. I and III only
C. II and III only
D. I, II and III

How well did you know this?

Not at all

Perfectly

What is a difference between two alleles of a gene?
A. Their positions on homologous chromosomes
B. Their amino acid sequence
C. The characteristic they influence
D. Their base sequence

How well did you know this?

Not at all

Perfectly

Which genotype would be normally found in a gamete?
A. Rr
B. RS
C. rStt
D. TUt

How well did you know this?

Not at all

Perfectly

How does sickle cell anemia happen?

Mutation happens were adenine is replaced with thymine to create valine instead of glutamic acid

How well did you know this?

Not at all

Perfectly

For what purpose is a karyogram used?

To identify abnormal chromosomes in an individual

How well did you know this?

Not at all

Perfectly

What technique was used by John Cairns to measure the length of the DNA molecule in Escherichia coli?
A. Autoradiography
B. Chromatography
C. Genome sequencing
D. Karyotyping

How well did you know this?

Not at all

Perfectly

Chromosome numbers vary between species. Which statement refers to humans?
A. An egg cell has 22 autosomes.
B. A sperm cell has 23 autosomes.
C. An egg cell has two X chromosomes.
D. A zygote has two autosomes.

How well did you know this?

Not at all

Perfectly

Which is a characteristic of the haploid number of eukaryotic chromosomes?
A. It doubles in mitosis.
B. It is fixed for each species.
C. It is an even number for all species.
D. It is positively correlated with an animal’s mass.

How well did you know this?

Not at all

Perfectly

What is characteristic of homologous chromosomes?
A. They have an identical DNA sequence.
B. They are of the same length in karyograms.
C. They form pairs in prokaryotes.
D. They carry the same alleles.

How well did you know this?

Not at all

Perfectly

Which of the following statements about homologous chromosomes is correct?
A. Each gene is at the same locus on both chromosomes.
B. They are two identical copies of a parent chromosome which are attached to one another at the centromere.
C. They always produce identical phenotypes.
D. They are chromosomes that have identical genes and alleles.

How well did you know this?

Not at all

Perfectly

What is chorionic villi and what are they used for?

Chorionic villi are tiny projections of placental tissue that look like fingers and are use for karyotyping as a source of chromosomes of a baby to run pre-natal diagnosis of abnormalities

How well did you know this?

Not at all

Perfectly

What commonly causes Down syndrome in humans?

Non-disjunction

How well did you know this?

Not at all

Perfectly

What happens in the first division of meiosis?
A. Formation of chiasmata where two sister chromatids join
B. Exchange of chromatids between homologous chromosomes
C. Exchange of DNA between non-sister chromatids of homologous chromosomes
D. Formation of chiasmata between non-homologous chromosomes

How well did you know this?

Not at all

Perfectly

Which process could cause non-disjunction if it occurred during meiosis?
A. Sister chromatids do not align in metaphase I.
B. Homologous chromosomes do not separate in anaphase I.
C. Sister chromatids do not align in metaphase II.
D. Homologous chromosomes do not separate in anaphase II.

What forms when two different chromatids of the same homologous pair cross over?

Chiasma

Which process occurs in meiosis but not in mitosis?

Movement of homologous chromosomes to opposite ends

What event occurs only in meiosis?

Random separation in homologous chromosomes

What is the chromosome number in human gamete with non-disjunction?

What is meiosis?

Reduction division of a diploid nucleus to form haploid nuclei

What causes genetic variety in the formation of gametes during meiosis?

Crossing over in prophase I and random orientation of homologous chromosomes in metaphase I

What do all human males inherit from their mother?

An X chromosome an mitochondrial DNA

What is amniocentesis?

It involves removing and testing a small sample of cells from amniotic fluid, the fluid that surrounds the baby in the womb/uterus.

In the fruit fly Drosophila, the alleles for red eyes and brown bodies are dominant to the alleles for white eyes and yellow bodies. Which cross would be suitable to determine whether the genes are linked? A. Heterozygous red-eyed flies crossed with yellow-bodied flies B. White-eyed flies crossed with homozygous brown-bodied flies C. Homozygous red-eyed, brown-bodied flies crossed with white-eyed, yellow-bodied flies D. Heterozygous red-eyed, brown-bodied flies crossed with white-eyed, yellow-bodied flies

What is the major health issue resulting from the Chernobyl nuclear accident in 1986?

Thyroid cancer

In a person who is heterozygous for sickle-cell anemia, where is the mutation found?

In brain cells

What term describes the failure of sister chromatids to separate during anaphase II?

Non-disjunction

What is combined in the production of cloned embryos by somatic-cell nuclear transfer?

An egg cell without a nucleus and the nucleus of a somatic cell

Amniocentesis and chorionic villus sampling (CVS) are used to test for fetal abnormalities. Which statement is a valid comparison between the two tests? A. CVS is performed later in pregnancy but has more risk of miscarriage than amniocentesis. B. Amniocentesis is performed earlier in pregnancy but has more risk of miscarriage than CVS. C. CVS is performed earlier in pregnancy but has more risk of miscarriage than amniocentesis. D. Amniocentesis is performed later in pregnancy but has more risk of miscarriage than CVS.

Genetically modified maize, called Bt maize, is thought to be affecting the monarch butterfly (Danaus plexippus) in the USA. What is the reason for this?

Bt toxin is in maize pollen, which blows on to plants that the monarch caterpillar eats.

Which statement about the polymerase chain reaction (PCR) is correct? A. PCR allows DNA to be cloned in a test tube and millions of copies can be made in hours. B. PCR allows the synthesis of RNA from DNA molecules. C. PCR is a natural process carried out by some viruses to amplify DNA molecules. D. PCR is a man-made technique used to identify the nucleotide sequence of DNA.